How Diesel Engine Works

How Diesel EnginesWork and Wear

EngineSystems . . . r .

Cooling Lubrication Fuel Air lntake& Exhaust Electrical

plus the commonwarnlng This bulletingivos an ovorviowof diesolengines,how they work and typicallywear, of €nginesand h6lp you give you thorough understanding a signsot engi;" problems. Tho objectiveis to Bepair Options' your Engine dealership's efiectivelymarxetCat€rpillaroproductsand

Abnormalwear is any wear oth6r than that from normalengineoperation, Generally,abnormalwear resultsfrom lncorrectmaintenanceor operating technique. Usingthe wrong oil, oxtondingoil changes intervals,nol maintainingthe coolantconditioner concentration,and inadequatemachinewarm-up are typicalpraciicesthat cause abnormalwear and prematureenginefailure, t is importantto understandlhat there are only live major wear tems in a di€se engine, and they re worth . cylinderliners . prstonings

. vaves, guides,and seats . main and rod bearings

a turbochargerbearingsand seals P l s l o n w l t h n o r m a l w o a r o ^ r l q h l , a b n o r m a lw e a r o n l e l t ,

EngineWear Hand in hand with the d scussionof how engineswork is how they wear. For our purpose,we will classify enginewear inlo two categories;normaland abnorma enginewear. Normalv{earoccurs in al englnes, As pa(s push, slideand work againsteach other, wear occurs. Nornal wear is that wl_ichwe e'pecl ou.ing eng;ne operation, The normalwear ltems in a dieselengine includethe p ston rings, cylinderliners,valvesand valve guides, main and rod bearingsand if equipped, turbochargerbearingsand sea s,

B € a r l n 9s h o w l n q a b n o r h a l w € a r .

lf lhese wear parts are replaced before they wear out approximately 80%of majorenginefailurescan be eliminated.

These parts are relatively inexpensive, and if replaced on a timoly basis, expensive components lik€ cylinder heads, blocks, crankshafts and connecting rods should nev€r n6ed replacement.

W € a r t r e m s r 6 p r a c 6 dw h 6 n r o p a k l n g b 6 l o r 6 l a l l u r e ( o n t h o l s l t ) . P 6 r t s r o p l a c o da l t s r l a l l u r € ( o n i h o r l g h 0 . unnscossary costs sssoclaled wlth alter lallure r€pahE.

Thlnkolih€

RepairBeforeFailure This concept is the basisfor the managementstrategy of repairingbefor€ failure. L€t's look at a quick comparisonbetweonbefore and after failurerepaks so we cloarlyunderstandhow ropairingbefore failure bonefitsth€ customer. In our after failure€xampletho customerignorestho repairindicatorsand continuesoperatingthe 6ngine untila main bearingfails causingmajor damageto the crankshaft. In fact the damageis to the point that the crankshaftcannot be used as a core lor a remanufactured crankshaft- addingslbstantiallyto the ropaircosts, In our beforefailureexamplethe ongineis maintainod correctlyand th€ repak indicatorsare monitored. when an S.O.S report warnsof bearingwear the engineis promptlyscheduledlor repair- before major failurocan occur. Tho inexpensivobearingsare

replacedand there is no damageto the crankshaftor other components, Usingthis €xample,let's summarizethe customor benofitsof repairingbeforefailure.

Nobody knows Cat equipm€nt d6sign and wear trends as w6ll as Caterpillarand Cat Dealers. They regularly pool informatjon to develop wear trends for accurately interpreting S.O.S lest results. Olher oil analysis programs simply don't have this critical information. The bottom line is, S.O.S is the only program that can determine wh€n wear trends go from acceptable to unacceptable- indicatinga problem. LJsedr6gularly, S.O.S can catch problems early so they can be fixed in minirnaltime and with minimal costs to the customer.

EngineRepairIndicatorKit

The kit is convenient and 6asy to use, ln the kit are such tools as: Temp€raiure Fecord€r Labels Coolant ConditionerTest Kit Fiher Cutter Crankcase Pressure Gauge

Also includedis helpfulliteraturesuch as an Overhaul EstimatorForm, EngineEvauationWorksheeland Sp€cialInstructions that give you the basic information neededto completea lhoroughengineeval!ation. Dealersalesmenar€ findingthe kit us€fulin buiding cr€dibility and professionalismwith thelr custon]ers. Now let's look at each oi the dies€lenginesystems individually.

l. CoolingSystem

Over40%of engineiailuresresultfrom coolingsystem problems. Of the live syslems,tho coolingsystemis the mosl criiicalto engineliie.

One of the oasiest ways to determine the overall conditionof an engineis 10 periorm some simple checks or tests. That is the purposeior the Engine ReDairlndicatorKit (ERIK). The kit includesthe basic tools needed to evaluate the engine condition and determinoii a before failureoverhau ls needed, or ii furtherdiagnosisis required.

Over 40/o of engine failuresare due to cooling

systemproblems. Tho compon6nts that makeup lhe coolingsystem includeth6 lollowing. T6mperature 9aug6

Thermostat

a Water Pump - The water pump providescontinuous circulationof coolantwheneverthe engineis turning. Water pumpson Cat enginesare genelallygear driven, excepton the 3208, 3j 14, and 3116 Engineswhich havo belt drivenwator oumos. a Radlator- Th6 radiatortransf€rsheat awayfrom th6 coolant, lowerinocoolanttemperature, Coolant flows throughthe radiatortub6s whileair circulatos aroundth6 tubes providinga transferof heat to the atmosphore. W€ have thrse styl€sof radiators, conventional-style, folded core, and the modular core radrator. o Coolant- Coolantis a mixtureof water, antifreeze (glycol),and coolantconditioner (inhibitor).For propercooling,each must be maintainedin th6 correct 9rooortion, . Th€rmostgl- Technicallythe thermostatis calleda temperatur€regutator. The thermostatassistsin enginewarm-up and h6lpsmaintaincootantand enginetempeEtureduringoperation. Whenthe 6ngineis cold the thermostatattowscoolant circulationjust throughthe engin6,bypassinqthe radiator(to h€lp the €nginewarm-up). Whenthe engineis at proper op€ratingtemperaturethe thermostatopensto allowcootantllow throughth6 radiator(so coolingtakes placo). The thormostat continuallyopens and closesas the cootant temperaturechanoes, . Water Temp€relureGaug€- The l€mperature gauge indicatesthe temperatureof the cootant. The recommend€doperatingranoo is g€nerally between190'-210oF(88"-99.C). . Fan - The tan forces air aroundthe radiatortubes to transferheat out of the coolantand d€crsase coolanttemperaturo. Fansare bolt drivenoff a crankshaftpulley. . Oil Coolers- Oil coolerslunctionto maintainthe corrcct tempetatureof engine,transmissionand hydraulicoil. Therear€ two basictypes: oil to coolantand oil to air. Oil to coolantcoolersare used most often for coolingengineand transmissionoil. Oil ftows throughtub€s whil€coolantftowsaroundth6 lub€s pickingup heat and lowedngthe oil temperature.

Oil to ajr coolersaro used most often for hydraulic systems,wherea much greatartemp€raturedrop is tequared,such as on many excavators. Air to oil coolersare similarin designand principleto radiators. Ak blowsacrossthe surfaceof oil cooler tubes dissipatingh6at awayfrom the oit to the atmosohere.

Howthe CoolingSystem Works

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The primarytunctionof the coolingsystemis to maintaincorrect enginetemperatureby takingaway unwantedhoat generatedby combustionand friction. Approximatoly 33% of th6 h€at €nergydev€loped duringcombustionis convert€dihto usabte horsopower,7% radiat€sdirsctly off enginesurfaces and 30% out the exhaust. The remaining30% is dissipatedby the coolingsystam. Coolantckculatesthroughpassagesin th6 engine calledwat6r or coolantjackets. The coolantabsorbs heat from the hot enginosurfacesand carriesit to the radiatorwh€r€it transfersto the atmosphere, The coolingsystemalso h€lps maintainthe correct temp€ratureof engine,transmissionand hydrauticoil throughth6 use of oil coolers. Now let's look in more detailat how coolantflows throughthe engine.

DiagnosingCoolingSYstem

Problems

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1 . Coolant llow is iniliated by the water pump that starts and continues pumping as soon as the engineis slarted. 2 . Coolant circulates through the engjne oil cooler to cool the engine oil. 3 . From lhe oil cooler' coolant travels into the engine block and around the hot cylinder linefs pickingup heat and coolingengineparts Then it travels through intricate passages in the cylinderhead(s) pickingup more heat aroundthe criticalvalve areas. 5. From the cylindorhead(s) the coolantgoes to the thermostat and on to the radiator for cooling li tne engine rs cold the thermostatwill remain closed and will recirculate the coolant through the enginebypassingthe radiator.

Engines with turbocharg€rs and aflelcoolers circulate oaitiallton,ot coolantfiom th€ water pump oirectlylo ihe aftercoOrer.Here the Coolanlis used tO lower th€ air temperature so that more air can be packed in lhe cv,inde., This allowsmore f,lel to be burned a"d c:eates highereng:nehorsepoweroutpul ln addlron' some machineshave torque converterand transmissionoil coolerswhich are also cooled by enginecoolant. 8

which causes the most engine failures problems with the cooling system or the lubrication system? Initially most people say th€ lubricalion system' however the correcl answer is the coolng system A cooling system that tuns too colcl causos rYlarginallubrication because the low tomperature prev€nts the oil from warming up so that it can flow and coat parts adequately. A cooling system that runs too hot also causes marginal lubrication b€cause the high temoeraiures breal down th€ oil properlies so that oaris are nol orotected correclly. Both cases of marginal lubrication can be traced back to cooling syst6m proolems

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OII al norhal op€ratingtemPsratureon the lelt' thlck on ih6 rlght' viscousoll at low t6mperatu16 Cooling and lubrication are closely related oecause tempeiature greatly affects lhe oil's ability to lubricate and protect Parts Properly Generally,e4ginesare designedlo operale between 190"-21ooF(88'-99'C) - and they will not operate well. or livo up to thoir exp€cted life, il continuallyrun either colder or hotter than this. lf the engine runs hotter (overheating), or iJ it continually operates oelow liris temperalure (overcooling), the result is the same - excessivo engine woar and damage Let s oxamlne overheating and overcooling and the indicators or warning signs o{ these Problems

Overheating Overheatingis by far lhe most w€ll-known cooling system problem. lf l6ft unresolved it will almost always cause quack, catastrophic engine failure, somgtimes in a matter of minutos.

Indicatorsot Overheating o S.OrS - high wear metals & oxidation . High readingon temperaturegauge . Crackedcylinder head . Turbochargertailures . High temperaturelabel readings Ov€rh€ating oft€n causesexcessiveor prsmaturering and liner wear, pistonscuffing,and bearingscuffing. Extremeoverheatingcan also cause the cylinderhead to crack.

Thls lllustrat€s rh. hea! bulld-up lgadlng ro a sotzur€ condlllon. Nole how h6ar afl€cis all parts torrnlnq th6 combusllon chamber, Includlng th6 valvos, luel nozzlo and cyllnd€rhoad. Without proper cooling, temperatures inside an 6ngine will soar, - €sp€cially around th€ combustion chamber

whereextremehot spots can dev€lop, Ovarh€ating causesparts to expandcausingmore friction,and thus more heat. Temp€raturescontinu€to increase untillhe parts cannotmove and will ultimatelysoize. For example,a pistonwill expandcausingthe clearancebetwoonit and the cylinderliner to decreaseto the point that the Distonseiz€sin tho liner, Often in this cas6, the pistonis pulledapan from the connectingrod and pistonpin allowingthe rod to breakthroughthe lin€r and go throughthe side of the engineblock. Catastrophicfailur€- and withoutpropercoolingit takes only a shon tim€ for such a failur€to occur, Overheating also caus€sa br€akdownof the oil which is the main safeouardaoainstwear. As lsmperatures increase,th6 oil thins out, destroyingits lubricating qualities. In this thinnedout state the oil doesn't have the strengthlo supportth€ parts adequately. lt doesn't providoa barrierbetwaanmovingsurfacos. The resultis metal-to-metalcontactand excessive

It's importantto note h6re how ovarheatingcan aflect the entire6ngine. Take for examplea customerwho had a crack€dcylinderhead due to overheating, roplacedit and then had a pistonseizurea shon ms later, The knownproblemwas the c€cked cylinder head, lt was €asy to diagnose, But unknownto the customerwas the additionalDroblemof scuff6d pistons. Whenth€ enginetemperatureincreasedthe pistonsexpanded,and the oil lhinnedout, causing scutfing. The sculfingcausodincreas€dfrictionwhich eventuallycausedone of the pistonsto s€izo. Both problems,the cGcked h€ad and scuffedpistons, occurrodat th€ same time, but only ono, the cracked cylinderhead, was diagnosed. Tho point is to thinkof all the consoquoncesof an overheatingproblem, beyondthe most obvious. S.O.S roportson €ngin€swith ov€rheatinglypically showelevatedconcentrations of w€ar metals,with no substantialincroasein dirt (silicon). kon (cylinder liners),chrome (pistonrings) and lead (bearing overlay)readingsmay incleasodue to the eflects of marginallubricationfrom ov6rh6ating. In addition, since heat acts as a catalystto the oxidationprocess, infraredtest r€sultsmay show elevatedoxidation reaotngs,

Overcooling Overcooling is less lndorstood than overheating' but the results can be just as damaqing. Both causo

heat, there will be no increased oxidation as occLlrs during ovorheating conditions ln addition to encouraging enrollment in S.O.S, check lhe following points to help insure the cooling system is operating

CoolingSystemChecks

o I on l6fl shaPodplstonat amblonll6mp€rature Elliptlcally Ths sah€ plslon at normaloporailnqtomPeraruroon rlght. Overcooling prevents the oil and parts kom getting to the correct temperature. This is especially prevalent during engine start-up and in low ambient temperature aoolications, In these situations the oil is cold and thick and doesn't flow correctly or quickly enough' resulling in marginal lubrication Also' when pans don't reach the correct operating temp6ralur€ they don't sgat together properly - causing wear' Pistons are a goocl example lf overcooling occurs. pistons don't expand to lit correctly" in tho cylindor' ln elf€ct you have an " out-of -round lelliptically-shapod) piston moving up and down in a round cylinder liner' The result is €xcessive wear around the piston skirl'

Indicatorsot Overcooling . Not enough heat in the cab o S.O.S - high wear metals, no oxidation . Low readingon temperaturegauge . Sculfed bearingsor Pistons lnstead of immediate engine failuro, which is common with overheating, overcooling causes woar that orooresses over a longer time. It an engino will norirally run SOOOhours to overhaul in an application' with overcooling il will typtcally run only 6000 hours Overcooling is harder to detect, but S'O'S is still the best indicator. The S.O.S results will be similar to overheating. However' since there is no excessive

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Thermostals- Whenthe engineis cold the thermostatassiststhe enginein lvarming-upand reachingcorrect operatingtemperaturequickly You can't tell by lookingat the thermostatif it's working correctly,how€verthere are some indicatorsthat will tell vou if it isnt workingcorrectly. In cold climates'il a thirmostat is stuck open it will tako an €xcessiv€ly long time for the engineto warm-up and littla or no heat will be availableto heat th6 cab. lf the thermostatis stuck closedthe enginewill overheat ln this case the enginewill be very hot whileths radiato hos€s and tubes are cool, indicatingthe coolantis not goingthroughthe radiator. lt is importantto remrno ownorsand oporatorsto neveroperatea Cat enoine or machinewithouta thermostat- overheatingcan result. CoolantTemp€ratur€Gsugo - lf you suspecia taulty gaugo,you can place a few temperaturelabslson th€ engineand aadiatorto get an approxamate te-p.ratrrt reading. ll you still susped a problam the servicedepartmentcan use a Thermistor Thermometertor a more accuratereadingand for turtherinvestigatron Emohasizewith customersthe importanceof using cori""t st"n-rp procedu@s. Remindthgm to not start ope6ting untilthe onginehas reachedthe corrgct temperature,indicatedby th€ coolant temperaturegaugepointingin the gre9n area Also warn them if the gaugepointsin the red area' indicatjngoverheating,the machineshouldb€ shut down or the loadsreducedimmediatelyso tho problemcan be inv€stigated.

Radiato.& F n - The radiator,fan and th6 surroundingar6a must be free of debds for adeouate coollng. Cleaningmust be performedas often 6s need6d. This might be monthty,w€ekty,nighrtyor even €very f6w hours, such as in some landfillor forestryapplications.Also rememb€rthat tooseor brokonfan bladesand belts will reduce coolingsystem efficiency. Reversiblefans are fr6quentlyused on machines workinoin landfilland oth6r applicationswheredebris can hind€rcoolingefficioncy. Reversiblefan btad€s can be turned 1800to eith€rblow air from the engino or to suck it throughthe radiator. tt is importantthat machineswith roversiblefans followthe Cat r€commendalions outlinedin the machinelaterature, otherwiseoverheatingcan result.

Coolanl or oll drlpplnq lrom !h€ wo6F hot€ on th€ std6 of lho wat€r DumD lndlcate. w6ar.

Waler Pump - Th€ major indicatorof water pump (coolantpump) wear is coolantor oil drippingkom the weep hole on th€ side of the Oump. This indicatesth6 pump seal is wearingand meansthe pump will need replacementsoon, Note, slightdrainingof coolantor oil from the weep hole is normal, A l€akyor worn pump seal can be identifiodil th€re is continuousflow or measurable coolantloss every day.

RadialorCap S€El- The rubborseal in the radiator cap must b€ in good conditjonfor correct s€alingand pressurizing of the coolinosystem. lf there are cracks in the s6al or signsaroundthe radiatorfilt ar6a indicatingthe coolanthas boilodov6r, th€ seal probablyneedsr€plac€ment. Cat coolingsystemsgenerallyoperateunder8-16 psi (55-110kPa)pressure.Thisraisosthe boilingpoint of the coolant. lf th€re ls inadequatesyst€m pr6ssur.6,thg coolantwill boil ov€r and the onginewill ovorneat,

Coolanl- Coolantis the mixtur€of water, antifrseze (glycol)and coolantconditioner(inhibitor). Cat Antifreez€protectsagainstboil-overs,heezingand corrosion. lt's significantto note that antifreezeis ne6dednot only in cold weather,but warm climates as well. In warm weather,glycol (antifreeze)is ne€d6dtoi rais6the boilingpoint, pr€ventboil-overs and overheating,to keep scale depositsto a mlntmum. Caterpillarrecommendsmaintainingthe glycol concentrationin coolantb€tween30-60%,depending on th6 aoolication.

that Cat Coolant Conditioner (inhibitor) is the additive parts' ol erosion orevgnts corrosion and cavitation baterpillar recommends maintaininga 3-6"/0 concentration of conditioner' regardless oi tne antilreere concentration A note here is that Cat lt ls Antitreeze already contains coolant conditionor' so (inhibitor) conditioner additional flOi n"""""u,u t; add on ini,iuttitt o{ the cooling systom with Cat Antikeeze' However, the conditioner concentration should be checked regularly and mainlained at the i".ommenoiO concentration. Gonerallyit is only necessary to add inhibitor at each engine lubrication Be service intervat {250 or 5OOservice meler hours) much sure rhe concentration is between 3-6%' too corrosion inhibitor will form insoluble salts which cause

Encourage customers to maintain their coolanf accoroirig to the rocomm€nded procedures in the Lutlrication and Mainlonance Guide Also' encourage the use of Cat Antifreeze and Cat Coolant Conditioner' Both products are formulated to caterpillar lor Cat "p""'i'c"tion" to provide lhe best proteclion eouromen(.

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Belts and Pulleys - The fan is belt driven off the crankshaft as are some water pumps cat recomm€nds about 1" (25 mm) play in the belts ano Belts should be checked daily for proper tension position ot sions ol cracking and wear. The correct tits in tne pullev grooves should be as illustrated' "ride" above the pulley grooves The belts should

System ll. Lubrication mai,1 The engine lubricating syslem has three parts' lubricate and cool, lunctions: to clean'

EngineOil 1. Cleans 2. Cools 3. Lubricates

as thrs Cavtarioneroslonwlll plt and corrode Paris such (bottom) llner cvrinder (top) and .n"-0..r J.*"-u,"it" wtthoLt lhe needed condil'oner.severecavitalion liner erosion will pit and corrode the outer cylinder llners' to tne next block the surfaces and surfaces o{ rt can not stopped lf Erosjon can be very damaging block cylind€r or liner the ,hrough iiog|.;"" "o.pr"*V

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. Cleaning: Oil cleans parts by carrying away durrng darnaging motal particles that materialize normal engino operation Oil also cloans the lacqLre cylinder walls and carries away carbon ano combust!on' produced during deposits part . Cooling: The second function oJ oil is to cool by absorbinq and carrying hoat away

. Lubricating: Thkdly' oil forms a thin film or layer parts to suppon between the surlaces of moving and separate them This prcvents metal-to-metal contact that causes excessiv€ wear'

The components of the lubrication system includ€ the following.

Howthe Lubrication System Works

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By-pass valv€

Dlpstlck

. Oil Pump - The oil pump operateswheneverthe engineis turningto providecontinuouscirculationof oil throughthe engine. . Oil Cooler - Coolant circulates through the oil coolor providing a heat transfer, fiom the oil to the coolant. This lowers the oil tomperature and protects the oil prop€rties. . Oil Filter - Th€ oil filter cleans the oil by collecting .aetal particles and other debris that can damage engineparts, . Oil Level GEuge (dipstick) - The dipstick provides a method to check the amountof oil in the engino. . Oil Pressure Gauge - The oil pressure gauge indicates the pressure in the 6ngine lubrication system during engin6 operation, . Oil Pan - The oil pan (sump) bolts to the boltom of the engine and is the reservoir for the engine oil. . Oil Fill Pipe - This is where oil is poured into the engine.

1. Oil travelsfrom the oil pan (sump), at the bottom of the engine, up throughthe oil pump and 2. th6n to the oil cooler. Here the oil is cooled by enginecoolant, 3. Then the oil goes through the oil filter(s) where debris and contaminants are removed, 4. Clean oil then mov€s into th6 oil manilold where it goes in two directionsi A. into the engine to lubricate components, such as th6 bearings, g6ars, pistons, lin6rs, valves,6tc. B. and a smallerflow directlyto the turbocharger. The oil then returns to the engine oil sump (pan) to start the cycle again. A bypass valve in the filter base allows unfiltered oil to by-pass a plugged filter so the engine will always hav6 some oil. When the oil is cold an oil cooler bypass valve bypassos oil around the oll cooler during start-up.

SYstem Lubrication Diagnosing Problems Thereare two major Ubricationsystemproblemsthat can cause excessiv€enginewear: inadequate lubricationand contaminantsin the oil.

Lubrication lnadequate Inadequatelubrication,or marginallubrication'can developfrofi a numborof causos. The most common, and the easiestto coriect, is cold engine sta.ts. Whenth€ enginsis cold, the oil is thick and doesn'tflowwell. lf enginespeedor loadis increasedbefore the oil is warmed-upmarginal lubricationwill occur. In effect, the parts will be operatjngwithoutadequat€oil. Followingthe recommendedstart-Llpprocedureswill eliminatethis problemand help assurelong enginelife. Notethat in extremelylow ambienttemperaturesauxjliaryoil heatersmay be required.

Lackof LubeIndicators . Low oil pressure . Scuffedbearings

In The Oil Contaminants The secondtyp€ of lubricationsystemproblemis contaminatedoil. The leadingcause is €xonded oil changep6riods. when oil changesaro pushed beyondtho recommendedporiodthere is a br€akdownof the oil itself and it losesits abilityto suspendcontaminants,som€thingsimilarlo a contaminantoverload. Whonthis happens, contaminantsembod themselv€sin bearingsurlac€s and other movingparts causingdamageand wear'

Oil lndicatorsot Contaminated . S.O.s - high metalsor silicon . Contaminants In usedoil lilters . Scratchedbearlngs,pistonsor rings . Milkycoloredoil (wateror antifreEze) Dirt and metal particlesare the most common contaminants,but soot, water, and antifreezealso contaminatethe oil causing€xcessiveengineweal. oil is the singl€larg€stcause or Note: Contaminated enginecrankshaftbearingtailur€ B€tween70% and 80% of 6ll crankshaftbearingfailuresare causedby contaminatedoil.

other calses of inadequatelubricationinclucle:

wrong Viscosityof Oil lf the oil is too thin, it will not coat the parts adequately; and if ('s too viscous, or thick, it will not flow correctly. In either case, the oil is not providing adeouate protect|on.

Not EnoughOil ll ther€ isn't enoughoil in the engine' there of course' will b€ inadequateprot€ctionbetwsenmovingparts. Tho resultwill be almostimmediateenginedamage Notoalso that even op€ratingwith a low oil level causesproblems. lt allowsair into the system' loweringthe lubricationsystempressurc,whichin turn preventssufficiontlubricationto some parts-

Overcooling Whenan engioeruns too cold it do€sn't get hot enoughto boil off water producedduringcombustion The waterthen mixeswith oth€r combustion by-productsformingacids. The acidsdamageoil propertiescausinginadoquatelubricationand excessivewear.

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Boarlngs on lstt ar6 damag€d from d6brls and fallguoi onos on rlghl show normal woar'

By far, bgaringsare the most sensitiveenginepartsto oil relatedprobloms,esp€ciallyturbochargerboarings. lf a lubricationproblgmexists,the first sign will be worn turbochargerbearings. Maindnd rod b€arings are the next most suscaptibleparts. But because they are thicker,they can often surviv€marginal lubricationlongerthan the thinnor,faster moving turbocharg€rbearinos. The point to rem€mberis; if boaringwear is a problem,th€ caus€ will normallybe found in the lubricationsyst€m.

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Beloreleavingthe discussionon contaminatedoil here's ong importantm6ssag6that needsto b€ discussedwith ev6ry equipmentowner. One of the b€sl ways to ext€ndenginelile is to simplychangeoil and filtors accordinOto recommendedschedlles. Also to inspectfilters regularly. Thesesimple procedurescannot b€ overstressed.

Oil Filters It's a good practicefor ownersand operatorsto cut open usad oil filters and examinethe tilter paper and oil for m6tal particlas.

Hereare some other ar€asthat can warn of lubricationsyst€mprcbl€ms,

Low Oll Pressure lf an oil filter plugs, a bypassvalv€will open and allow unfilter€doii to lh€ engine. The operatormay notice a slightreductionof plessureon the gauge, for example,Irom 50 to 45 psi (345to 310 kPa). When the filtor is r€placed,the pressurewill go back up to the previouslevel. Extremolow oil pressuremay indicatea dangerousproblempossiblycausedby an insufficientamountof oil, a malfunctioning oil pressur€ pump gears, reliefvalv6, or worn oil

Cat Filters and Fluids Caterpillar Filters and Fluids ar€ speci{ically designed to provid€ Cat €ngin€s and equipment the best protection aoainst excessiv€ and costly w6ar.

:t t Cunl.g op6h oll tlltors ls rh6 bost vlsualch6ck for cleloctlng Intsrnal on9ln€ w€ar,

Otherthan S.O.S, this is the best methodfor dotectinginternal6ngin6wear. h's a practic€that shouldbe a regularpart of th€ oil and filter change procodure. SeOoS We've akeadydiscussedS.O.S as a indicatorfor siOnaling acceleratedenginewoar. lt shouldalso be notedthat it monitorsthe conditionof the oil. S.O.S indicatosif tho oil is contaminatedor if the orogenies of tho oil are breakingdown.

Cat Filtersare manufacturedto meet exactino requirementsof each enginemodel. Th6se help preventthe filter from pluggjng specifications prematurely,.uptu ng or passingdamaginodebris. Cat DieselEngin€Oil is specificallyformulatedto reduc€depositsand providethe b6st wear protection for Cat dieselengines. Cdt EnginoOil also provides oxcellentprotectionand is recomm€ndedfor mixed fleets or other brandsof onginos.

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lll. FuelSystem h is the function of the fuet injoction pumps and injectors 10 supply fuel into €ach cylinder in tho correct amount and at the right time ior efficient combustion. The components of th€ fuel system include tho following'

prrmrng

Sscondarv ru6t lthor

DireclInjoctlonEnsin€ . Fuel Tank - The tank is the reservoir for holding tuet, . Fuel Trsnsler Pump - The transter pump marntarns a constant flow of low-pressure fuel kom lhB fuel tank 10 the enginefuel system. Not6, th€ transfer pump is diflerentJrom the tuel injectionpumps. . Fuel lnj€ction Housing All engines,except those with unit injectors, have a Iuel iniection housing that holds the individualfuel injection pumps (one per cylinder). . Fuel lnj€ction Pumps - There is one fuel injection pump for each cylindor. Unliketho fu€l tlansfor pump which is low pressure,the fuel injection pumps operate at high pressure, Injection pressurescan run kom 2,800 to 20,000psi (19,290 to 137,800kPa). Each pump rnetersthe correct amountof fuel and pumps it, at a high pressure, through metal lines to each luel injector. . Unit Injeclors - The unit injector combines a fuel injection pump and a fuel injector into one assembly. Unit injectorseliminatohigh pressure fuel lines between the pump and injoctor allowing for higherfuel injoctionpressures. 16

. Fuel Fillers - Fuel passeslirst througha primary, then a secondaryfuel filter. lt's criticalto have cl€an fuel for these high pressurspumps Someo the clearancesbetw€enparts are as smallas a tew millionths of an inchand evonthe smallestdebris can causedamage, . Water S€parator- Waterseparatorsare usedlo protectagainstrust causedby water-contarnlnate fuel. All 3208 engin€shave water separators Note they are not standardequipmenton all engin€sand shouldb€ used on any enginewh€re water contaminatedfuel is a problem . Fuel Pr6ssureGaug6- This gauge readsthe pressureg€neratedby the luel lransferpump down streamlrom the tilters. It a filter becomesplugge a pressurereductionwill show up on the gauge.

. Fuel Lin6s - Fuel linesare most commonlydefine as thoso from the fuel injectionpump housingto th iniectors. On orecombustionand direct injection €nginesthe fuel linescarry high pressureluel Sinceunit injectorshave the injectionpumpsbuilt into the inioctorassgmbly,they do not have high pressurelrnes,

Howthe FuelSystem Works

with traditional precombustion and dkect iniection systems,

There are tvrc methods of detivering fuel into the combustion chamber; the first is precombustion, where fuel b€gins ignitionin a precombustionchamber before going into the cylind6r;and the second is direct injection, in which the fuel is injected direc y into the cvlinder for combustion.

The fuel travels through all Cat Engines in basicatlythe same way, up until the point of fuel injection. (1) Fu6l goes from th6 tank, (2) through a water separator, (3) through a primary fuel filter, and (4) into the luel transfer pump. (The primary filt€r can be before or afler the transfer pump). From the transfor pump luel (5) goes to a secondary lilt6r, and then either (6) to a tuel injecdon pump (precombustion and direct injection) or to a unit fuel injector.

It is also important to understand unit fuel injectors which are used on many of the latest model Cat engines. lJnit injectors use a direct injection method of fuel dehvery but they are dif,erent lrom engines

D l r € c t l n l e c t r o nE n g l n e

Precombustion The precombustionchamber (PC) systemis found primarilyon older model engines. Fuel is putledfrom the tank by the fuel transferpump and pumped throughthe primaryand secondaryfuel filtersto the fuel injectionpump hous;ngwherethe individualfuel pufips are locatgd (one per cylindor). The luel injgctionpumpsforce fuel throughhigh pressurefuel linesto the fuel nozzlesmountedin lhe cylind€rhead. A precisiondrilledholo in the end of each nozzle atomizestuel as it entersth€ precombustionchamber. As the fu6l beginsto ignite,the heat of combustion torces the remainingfuel and air mixtur€throughan orifice in tho precombustionchamberinto the cylinder. Glowplugsar€ mountedin the PC chamberhousings to warm the air and assistin startingPC engines, lt's easyto idontifyPC enginesbecauseof ths etectrical glow plug wires runningto each precombustion chamberin the cylinderhead. And, you can easily tell pistonson PC enginesby the steel heat plug mountedin the center on 6ach piston. 17

DirectIniection

Manyol the latest mod6l Cat engin€s,includingthe 35006nd 1.1 LiterEnginesuse unitfu€l iniectors. Each unit injectorhas a high pressureinjectionpump and injectornozzlebuilt-in 6ach unit assembly. Ther is one unit injoctorfor each cylinder.They are mountedin th6 cylinderh€ad. Low pressurofuel is deliveredfrom the fuel transfergump to aach unit injoctor,then throughthe injectorassemblydirectly into the cylinder. A rockerarm assembly,similarto that usod to operatethe enginovalv€s,operatoslhe fuel injectionpumps. By eliminatingthe fuel lines,the injoctorpresssrescan be increasedresultingin more efficiantatomizationand combustaon.

FuelSystem Diagnosing Problems Underfueling

On direct injection (Dl) enoines fu€l travels from the tank through th€ filters, pump, and lines to the injeclor housing the same as on precombustion engrnes. However, inst€ad of pre-ioniting the fu€|, direct injection engines inject frlel directly into the cylinder' You can tell pistonson Dl enginesbecausethe lop of the piston crown has a conical crater design and no steel heat plug.

UnitInjectors

occurs whenthero is not snoughfuel to Und€rfueling power meet the demandson the engin6. lt doesn't normallycause enginedamagebut will cause a lack of pow6r. Most often the cause is a pluggedfuel filter,and th€ remedyis to simplychangethe lilter.

Indicatorsot Underfueling . Low power . Lowfuel pressure(pluggedfilter)

CorrectFuel

The typ€ of diesgl fuel as well as th€ maintenanco of the luel is important to the performance and life ol ar 6n9ine, First, the fuel must be clean _ fr66 of waler and contaminants, and second it must be the corroct type for the application,

lndicatorsof Incorrect Fuel . Difficult starting . Enginecutting out

In low ambienttemperatures,liohterfuels, liko dies€l fuel numbor1, are us€d to gr€ventproblemsof fuel jelling (a situationwh€rethe fuel coagulates preventingsufficientflow).

18

In ar6asoutsideNorthAmerica,it's importantth6t ownersmatch the TBNnumber (TotalBaseNumber) ol the engineoit to the sutfurcontentof th€ fu€|. NormallyTBNadditivesin th6 engineoil neutlalizefu6l sulfurby-productswhich rosultfrom combustion, How€ver,if ths concentrationof sulfur in the fuol is too high, or the oil TBNtoo low, sutfuricacid will dev€lop. This can cause corrosionand 6xc6ssive wear of pistonrings, b€arings,and liners. To countor such problemscustomerscan changeto a higherTBN oil or shonen the oil chanoeintervals. Note: recommendshorteningth€ oil changeintervalsonly after thoroughdiscussiohwith ths appropriate Catergillaroersonnel.

Overfuellng Overfuelingoccurswh€n too much fuet is injoctedinto lhe cylind€r. Excossivebtackexhaustsmok6 is the loadingwarningsign. Therearg many causes,such as a high fuel rack setting,misadjustgdaklfu€l ratio controlor faultyfuel injector. All involv€the fuel systemand must be handledby appropriate dealorships6rvic6oersonnol.

Indicatorsof Overfuelingor Incorrect Atomization . Black smoke

burningstrcam of fuel, much like a cltting torch. The temp€raturesget so high and th€ burningis so concentratodthat it can actuallyclt into the piston. In addition,som€ ol the unburnedfuel runs downthe lin€rwalls. This washosoff the protectiveoil, rcducinglubricationand acc€leratingdng and liner wear and pistonscuffing. Whenfuel is not atomizedcorrectly,the combustion proc€sslakes longerthan normal,leavingunburned fuel in the cylinder. Again,the problemof fu6l runningdownthe liner wallsoccurs. This is typicallya fuel systemproblomand shouldbe handledby the servic€depanm€nt, The leadjngindicatorsare; excessivoblacksmoke, a lack of power,and fuel contamination of th€ engineoil,

lV. Air Intake& Exhaust System The ak intakesystemsuppliesclean ak for enoino combustion. Ths exhaustsystemtakes awayexhaust gasesand h6at, and driv€sthe turbocharger. The componentsthat mak6 up the air intakeand exhaust systemincludethe following.

. Increasedtuel consumption . S.O.S showingtuel In the oil

Plstontallur. du6 to Incorr.cttuot InJ6crton Wheninconoct atomizationor fuol injectionoccurs, fuel is Injectedinto thg cylind€rin a stream inst€adof in an atomizedstato, This happonsif an injsctoris pluggedor has a brok€ntip. Instoadot a smooth, completebuhing of th€ fu€I, the liquidignitesinto a 19

Pr€cleanel- The pr€cleanerremoveslarge paniclesof dirt and debris. I Air Filters - Usually there are two air filters' a primary and secondary lilter. They collect contaminants and prevent dirt from entenng tn€ 6ngine. r Air Filter Service Indicator - The indicator monitors restriction through the air filters. lt is the most accurate method for determining when to change air filtors, Every engineshouldhave ona An interesting tact is that changing filters too olten can actually do more harm than good - because dirt can so easily enter the engine during a lilier change. This mak€s lhe indicator a very useful and importantmaintenancetool

Howthe Air IntakeandExhau SystemWorks

a Turbochatger - Exhaust gases drivB the turbocharger which pumps additional air into lhe engineallowingmore fuel to be bLlrned'thereby increasing the horsepower output . Aflercooler - The aftercooler cools the air aiter it leaves the turbocharger but before it enters the engine, This increases lhe air density' so more alr can bo packed into each cylinder.

. Air Intak€& ExhEuslManifold6- The air intakeand manifoldsconnectdk€ctlyto the cylinder exhaLrst cleanair dislributes nead(s), Theintakemanrlold intoeachcylinder' irom the air tilteror turbochargor exhaustgas€s collects manitold whilethe exhaust to the them lrom each cylinderand dkects and/orto the muffler. turbocharger . Mulfler - The mufller reducesthe soundlevel and providessufticientback pressureto the engine,so th6 enqins"broathes'asdesignad.

1 . Air first entersthe systemvia the precleaner'

H€re large dirt particlesare removed 2 . Then air movesthroughthe primaryand secondaryair filterslor further cleanrng' On turbochargedongin€sths spinningo{ the turbochargercomprgssorwheelpulls air Into tne turbocharger. 3 . The complessorwheelcompressesthe air (whi also heats it) and s€nds it to tho aftercoolor' The aftercoolerreducesthe air temperature makingit more denseso more air can b€ pack into the cylind€rs 4. Tho densecompressodair mov€strom the aitercoolerthroughthe air intakemanitoldand cylinderhead(s) 5. past the intakevalv€sinto €ach cylinder combustlonchamber. As the intakevalvesclo and thg pistonmovesup in the cylinderthe air comoressgdturther. when lhe pistonis near I roo of its stroke, fuel is injectedinto the combustionchamber, The fuel mixeswith the hot, compressedair and ignites The force of the combustionpushesthe plstondown on the

6. Wh€nth€ pistonmoves up againit is on tho exhauststrok€. The €xhaustvalvesopen allow exhaustgasesout throughthe oxhaustmanifo

20

T h e c o m b u s r l o nc y c l €

On engineswithoutturbochargersair movesdir€ctly from the precleanerand air cleanerthroughthe intake manifoldinto the cyljnd€rs. After the combustion cycle, exhaustgases exit throughth€ exhaustmanifold and muffler.

Diagnosing Air Intake& ExhaustProblems The two major problems associated with the air intake and exhaust syst€m that can affect engine performanc€ and life ar6: not enough air and dirty air.

Not EnoughAir E x h a u F tg a

lndicatorsot Lack of Air . Black smoke

Turbocharger operation

. Low power

Exhaustgasesflow throughthe €xhaustmanifoldinto the turbineside of the turbochargerto drive the turblnewheel. The turbinewheelis connect€dby a shaftto lhe compressorwheel, The compressor wheelpullsair into the system. Exhaustgases aft€r drivingthe turbinewheel pass out throughthe muffler and oxhauststack.

. Hard starting

2l

-

Wh6nair tilt€rs becom€ pluggodor there is a restrictionin ths system,tho engineis staNed for ak. The enginecan not efficiontlyor completelyburn the fuel. Most often this problomis diagnosedby an operatorwho complainsof excessiveblack smokeor a loss of power- before actlal €nginedamage occurs, Tho most commoncausesof air rostrictioninclud6the followin9. PluggodAir Flli€rs - Dirty, plugg€dair lilters are the most ovorlookedand yet the primarycaus€ ol air restriction. Th€ first item that shouldbe ch€ckedil ther€ is blacksmoke or a lack of powercomplaintis th6 ak filter. Rem€mberair filter serviceindicators are the most accurateway to knowwhen to cnange the air filters. They shouldbe recommendedlor all €noines,if not alreadyequipped.

Tho ak fllt€r sorulc6 Indlc.tor

M6lfunctioningTurbochsrger - ll turbocharger bearingsor sealswear to the point that turbocharger speed is reducedor if the bladescontactthe housing thers will be insufficientair going to th€ cylindersfor comol€tecombustion. PluggedAft€rcool€r- Any restrictionin ihe aftercoolerwill docreasothe amountof air into the cylindors, ExhaustBestrlction- A restrictionin the exhaustwill slowtho turbochargersince it is drivenby exhaust oasos. This will reduc€the amountof intakeair going into th6 cylindersand calse a loss of powor. Exhaust rcstrictionscan be causedby customizedexhaust systemsthal are incorrecttymatchedto the engin6' damagedmufflersand pipes and other items that restrictair flow.

Anythingthat inhibitsor restrictsair coming into tho engin€,throllghthe air filt€r, turbochargeror aftorcoolor,or going out, throughthe exhaustsystem will affect eltici6ntcombustion. As noted betor6' the l€adingindicatorsar€ black smoko, which indicates unburnedfuel (du6 to not €noughintakeair) and a loss of power.

Dirtyair Indicatotsof DirtyAir . Highoil consumption . Worn: Rings Liners Bearings Turbocharger Pans

Dkt in an enginecauseswear' As little as one teaspoonof din can cause severedamageand possiblyshut the enginedown. Commonproblems that can allowdirt in an engineincludea split or sma pin-holein a hose, a loose hose or pipe connection or a to.n air lilter. Dirt that ontersthe enginecollectson the oily cylind lin€r walls. As th€ pistonrings movo r'lpand down alongth€ wallsthe dirt causesfine wear, much likg sand oap€r, on the pislon ring grooves,ringsand cylinderliner surfaces. S.O.S is the b€st indicatorof dirt entry Belorew€a of the ringsand linerswill cause blowbyand increas oil consumptionS.O.S will warn ol an increasein siliconlevels- alortingthe ownerto a problem.

OilConsumption andBlowby

t,

Corroct rlng and llner contact

,iii

Woar rnd Incr6asod oll consumDtlon

N o r m a l € n g l n e o p € r a t l o no n l h e l e l t , r l n g a h d l l n o r w 6 a r c a u s l n s I n c r e a E e do l l c o n s u m p ! l o no n i h 6 r l g h t .

Here is a good plac6 to explainoil consumptionand blowby. Oil consumplionoccurswhen lubricatingoil on the cylinderliner wallsis allowodpast the piston rings into the combustionchamberor when oil passes antothe combustionchamberdue to excessive clearancebetweenthe valvesand *tt q'l::-:--,- d, Normallythe ringscontrolthe amountand thickness the oil on the liner wall, but if wom, the increased clearancebetweenthe ring and linsr allowsexc6ssiv6 amountsof oil in the combustionchamber,.Th€ oil then burnsalongwith the fuel. As the engine oporates,additionalamountsof oil are consumed creatingth6 need to continuallyadd oil to the engine.

Blowbyoccurswhen combustiongsses travel past th6 ringsand/or valvesand valv6 guidestrom the combustionchamborinto the crankcase. This allows carbon,soot and othsr contaminantsto mix with the oil increasingenginewear. other causes ---- of - increased - oir consumptionand browby n"frOa a worn tulbochargelbearingsand s€als a worn crankshaftseals . worn oil-lubricatedgovornorseals . oil l€akinginto the ,!el or coolingsystems

23

O consumbtton occors on rho lhtak6 s[oko as too much oll ls l6il on lho cyllnd6r llner wh€n tho plston hovo3 downward, Blowby occurs on th€ compresslon and powor slroko as aas€s pass b6tw66n worn rlngs and llnerc'

Th6 terms oil consumptionand blowbyare otten used interchangeably.To assistin diagnosingengine problems,blowbyis a more specificterm and is easierto measurelhan increasedoil consumption. Blowbycan be checkedby measuringcranKcase pressurewith a pressuregaugeor by chockingblowby volumewith a blowbymeter. Oil conslmptionis harderto measlrrosince it dependson good many consistentmaintenancerocords- somethang customersdon't have. Also blowbycan be moasured at any time. wheroasoil consumptionhas to be measuredover sev€raldays or weeks, The important pointis oil consumptionand blowbyboth r€sultfrom €nginewear, and the most commontype ot engine wear is pistonring and liner wear,

V. ElectricalSystem Batt€ry

Plug

The primaryfunctionof a dieselengine'selectrical systemis to start the engine. The secondaryfunctio is to powerlights,gaug€sand vehicleelgctrical components. (som6 of the latest€nginesin the on*highwaytruck marketalso have electronictuol controls). It's intgrostingto noto that after crankinga diesel engine,the batteryis no long€rneededto continu€ runningbecausether€ is no ignitionsystemrequired fot combustion,as on a gasolineengine

24

MaiorComponents in the Electrical

System . Battery- The battorystoreselectricalenorgy. a Alt€rnelor- Th€ alternatorcreatesolectricalenergy to replenishth6 charge level in the battery. A voltageregulatoris insidethe alternator. . Slart€r - The start€rmotor is poweredby el€ctrichy Irom th€ battery. lts functionis to start the engine. . Glow plugs - Glowplugs pr6h6atthe air for easier enginestarting. Th6y ar€ only found on pr€combustion engines.

Howthe ElectricalSystemWorks

The batterystoreseneroyand providesthe pow6r neededtor the sloctricalstarterto crank the engine. As electricalenergyis used out of the batteryit has to be replenished.Tho alternatordevelops€lectrical enorgyduringmachineoporationto replenishth6 battery.

Fot quickerand aasier€ngin€starts, precombustion sng;nesus€ €lectricalglow plugsto warm and preheat th€ air in the precombustionchamberbefore cranking. They heat for approximat€ly one minute. And even at 60"F (15.5oC)temperatur€sit's a good practiceto heat th€ glow plugsfor a short time. lf not preheat€d,th€ extremetemperatur€change,from ambi€ntto combustiont6mper6turo,can causeth6 tips of the glow plugsto br€ak off. Basicallyit's b€ttorto h6at them up graduallywith el€ctricitythan to shockthem with combustionheat.

Dlagnoslng EleclrlcalSystem Problems Battery

A majorityof electricalsystemproblomsar€ relatedto the balt€ryand most commonlyresultfrom a lack of maintenanco.Battarymaintonanceis very simplekeep the batteryfilled, clean, and clampoddown corl€ctly. ll not secur€dcorrectlywith the clamps, the batt€ry will bouncearoundduringmachineoperationcausing the internalplatesand connectionsto crack and break resultingin a batteryfailure. Extremejarringcan ev€n cause the cas6 to crack, allowingths fluid to leak.

Glow plug uEod tor siartlng prooombustlon 6ngln€g

25

SlowCrankingSpeed

Dieselenginesrequiresufficientcranl(jngspo6olo developtie high compressionpressuresneededto idnitethe fuel. lf th6 crankingspeed is slow the e;oine will be hard to start. Beforecallingthe servrc lf d"_pun-"nt.h""k th" batt€ryand all connections th6 problomis still not identiti6da servicemancan ItLJx tne "ta.ttr ano moasur€the crankingrpm ol the 6ngin€ The starter or batterymay need ropalror replac6m€nl

OtherMaterialonCatEngines & EngineRePairOptions Battoryterminalsand connectionsshouldbe cl6anand corrosion-free. on oth€r than maintenance-tree batteries,the lluid level must be maintainedaccordrng to the Lub.icationand MaintenanceGcommenclations. i;e €lectrolyteconc€ntrationcan be checkedwith an hydrometer. This tells how much chargeis in the "dead' baltery is rechargedovernight Oattery. tf a and i; th€ morningstill showsonly a low chargeor no chargeat all. the bstlery will no longeracc€pl a chargeand must be replaceo.

GlowPlugs Hardstarting.crankinga long tim€ or runningrough glow untilthe enoin€is warmodup aro signsthat the glow correctly Each olrjosmav iot be {Llnctioning an electricalmeter' with checked olui can be easily tune ups and as a during ptugs checked 6r€ inJ gtow overhauls' engine the reoularpart of each of

Alternator& VoltageRegulator Oncothe engineis running,the alternatorservosas gauges'E[4S tnr "t."t|.i""ipo,n"|. sourceto run lights, the plus replenish oanels,and eiectricalcomponents, ofl the chargein the battery. lt is belt driven crankshaft. lnsidethe alternatoris a voltageregulatorthat limits the voltag€outputto the battory. This prevents overcharglng. systeman lf a oroblemdevelopswith the charging "on" Thiscould will in cab lhe lioht Oo alto;nator sionalthe alternatoris not supplyingan adequate "tiu,g", o, " wiro is not connectedcorreclly ll not .orrJcted, tn. electricalenergywill drain out of th€ batteryuntil no more charge remains'

26

For moro informationon Cat Englnesand Cat Engin Repairoptionscheck the followingmaterials o ERIK- Engin€RepairIndicatorKit - Pari number 4C3502 . lntroductionto Di€selEngines- TECB6005 (TrainingBull€tin) . Guid€for ManaoingEnginePerlormance PEDP71Ol(Advertisingbrochure) . Howto PreventEngineFailure- PEDP6101 (Advortisingbrochure) (Flipchart) o Cat EnginoPartsQuality- PELP7901 "Decisions"- PEVN6020 . EngineR€pairOptions (VideotaPe) . Sch€dul€dOil SamplingSrOoS- PEDP7105 (Advertisingbrochure)

Air FilterServiceIndicator- pEHp9O13 (Adv6rtisingbrochure) Oil and Your Engine- SEBD0640 (T6chnicalPublication) Coolantand Your Engin6- SEBDog70 (TechnicalPublication) Fueland YourEngine- SEBD0717 (TochnicalPublication) KnowYourCoolingSystem- SEBDo5IB (TechnicalPublication) catelpillar'sMachineLubricationRecommenoaI|ons - SEBU6250 - (T€chnicalPublication) Thereare many oth6r matorialsavailabl€,check the I\rarketingTrainingMalerialsCatatog(TECM005O) and ProductSupportPromotionMatoriatsCatatog (PEGP9800) for compl6tatistings. (your d€al€rship Promolionand/or TrainingManagerhave these catalogsavailabl6.)

Conclusion You now have a good undorstandingol how diesel engines work, how they wear and the common warningsigns of problems. use this knowledge to h€lp your customersi a develop correct prBventativomaintenance practicos . choose appropriate inspsction programs . solect the best repair options for their spec.tic situation And, as a last note, remember to always demonstrate and reinforce with cilstomers that your dealership's capabilitiesand Cat products offer the best vatue available.

lndex Wl e a r. . . . ' . . . . 2 N o r m avl s . A b n o r m a R e p a iB r e f o r eF a i l u r eB e n e f i t s . . . . . . 3 SrOeS- ScheduledOil Sampling... 5 ERIK- EngineRepairIndicatorKit .. 6 ................6 l . C o o l i nSgy s t e m .,,.,.,.. 7 Components W P r k s. . . . . . . . 7 H o wt h e S y s t e m P r o b l e m&s I n d i c a t o r. s. . . . . . . . 8 O v e r h e a t i n. .g. . . . . . . . . . I ... . . ........ 10 O v e r c o o l i .n. g T h e r f i o s t a .t .s. , . . . . . . . . 1 0 C o o l a nGt a u g .e. . . . . . . . . . . . . . . 1 0 11 .. R a d i a& t oFra n . . . . . . R a d i a t o r C a p . . ... . . . . . . 1 l WaterPump... . . . ...... l1 C o o l a n t . . . . .. .. . . . . . l l B e l t s& P u l l e y .s . . , . . . . . . . . 1 2

l l . L u b r i c a t iSo yns t e m. . . . . . . . . . . . ........ ' Components H o wt h e S y s t e mW o r k s. . . . . . . . P r o b l e m&s I n d i c a t o r. s. . . . . . . . I n a d e q u aLt eu b r i c a t i o .n. . . Wrong Oil . . . . . . . . . . . . . . . N o tE n o u g O h il ......... . . . . . . . . . O v e r c o o l i n .g. . . . . C o n t a m i n a ot ei ld. . . . . . . . . . . . . Oil Filters . . . . . . . . . . . . . . . .

12 13 13 14 14 14 14 14 14 15

s . o . .s. . , . . . . . . . . . . . . . . 1. .5. . . . . . 15 L o wO i lP r s s s u r.e. . . . . C a tF i l t e&r sF l u i d s. . . . . . . 1 5

I t l .F u e lS y s t e m Components

...... 16 ..... '... 16

Th€ lnrormatloncontalnodh6rolnls Int6nd€dfor clrculatlon onlvto Cat€rplllarand d€al€r6mployo€swhoss dutles requlrsknowledgoof such roports 6nd ls Intsndsd excluslvelylor th6lr lnformatlonand training, li may contalnunvorlflodanalysrsand tacts obssrv€dbv various caterplllaror dsaler 6mploysss.

W o r k s. . . . . . . . 1 7 H o wt h eS y s t e m . .n. . . . . . . . . 1 7 P r € c o m b u s ,t .i o D k e cI tn i € c t i o. .n. . . . . . . . . . . . 1 8 l J n iItn j € c t i o. .n. . , . . . . . . . . . 1 8

P r o b l e m&s I n d i c a t o r.s. . . . . . . . 1 8 U n d e r f u € | i n g . . . . . . . . . . . .1. 8. . . . C o r r e cFtu e.l . . . . . . . . . . . . 1 8 O v e r f u o .l i. n. .g. . . . . . . . . . . . 1 9

tv. Air Intake& ExhaustSystem ... 19 C o m p o n e n. .t .s. . . . . . . . . . . . . . , 2 0 H o wt h e S y s t e mW o r k s. . . . . . . . 2 0 Turbocharger Operation. . .... 21

&sI n d i c a t o r. .s. . . . . . . 2 1 Probfem Not EnoughAlt . . . . . . . . . . . . . . . 21 P l u g g eAdi rF i f t e r. s. . . . , , . . . 2 2 Problems. . .... 22 Turbocharger P r A f t e r c o o l e o b l e m .s. . , . . . . . 2 2 E x h a u sRt e s t r i c t i o. .n. . . . . . . 2 2 D i r tAy i r . . . . . . . . . . . . . . . . . . 2 2 & Blowby. . ., 23 OilConsumption

E l e c t r i cSayl s t e m. . . . . . . . . . . . . . ,........ components H o wt h e S y s t e mW o r k s. . . . . . . . P r o b l e m&s l n d i c a t o r.s. . . . . . . .

24 25 25 25

25 . , 2 6 . . . , , . . . . G l o w P l u g. s , 26 A l t e r n a .t .o, r. . . . . . . . , , . S l o wC r a n k i n .g . . . . . . . . . 2 6

Battery

OtherMaterials Concfusion

'. " " 26 "'.."'27

How6vor.€flort has bssn mad€ to provld€rellablBrosults r€gardlnqany IntormatloncomparlngCatorplllarbullt 6nd comp€tltlvs6qulpm€nt. Ellort has b6on mad6 to uss th6 that th€s6 616 subj€ct lat€3t mat€rialIn th6 tull und6rstandlng to chanqewlthoutnotlca Anv rsDroductlonot thls rel€asewlthoutth€ forsgolng ls prohlblted. copynght 1989Cat€rPlllarhc exDlanatlon