ASE A1 (ENGINE REPAIR) PRACTICE TEST – CUMULATIVE QUESTIONS AND ANSWERS

ASE A1 (ENGINE REPAIR) PRACTICE
TEST – CUMULATIVE QUESTIONS AND
ANSWERS

anvbenginevbmissvbisvbbeingvbdiagnosedvbusingvbavbcylindervbleakagevbtest.vb
TechnicianvbAvbsaysvbthatvbanyvbcylindervbwithvbovervb20%vbleakagevbhasvbexcessivevblea
kage.vbTechvbBvbsaysvbthatvbairvbleakingvbfromvbthevbtailpipevbindicatesvbavbcrackedvbcylind
er.

Avbonly,
Bvbonly,
vbAvb&vbB,

Neithervb.vb-vbanswer--Avbonly:

Ifvbcylindervbleakagevbexceedsvb20%,vbcheckvbforvbairvbescapingvbthevbtailpipe,vbthevbPCVvb
valvevbopeningvbinvbthevbrockervbarmvbcover,vbandvbthevbtopvbofvbthevbthrottlevbbodyvborvbcar
buretor.

Airvbleakingvbfromvbthevbtailpipevbusuallyvbindicatesvbanvbexhaustvbvalvevbleak

duringvbavbcompressionvbtest,vbavbcylindervbhasvb40%vbofvbthevbspecifiedvbcompressionvbre
ading.vbWhenvbthevbtechvbperformsvbavbwetvbtest,vbthevbcompressionvbreadingvbonvbthisvbcy
lindervbhasvb75%vbofvbthevbspecifiedvbreading.vbThevbcausevbofvbthevblowvbcompressionvbre
adingvbcouldvbbe

wornvbpistonvbrings,
avbburnedvbexhaustvbvalve,
avbbentvbintakevbvalve,
avbwornvbcamshaftvblobe,vb-vbanswer--wornvbpistonvbrings

ifvbcompressionvbincreasesvbduringvbavbwetvbtest,vbthisvbindicatesvbwornvbpistonvbrings.vbC
ompressionvbwouldvbnotvbincreasevbifvbanvbexhaustvbvalvevbisvbburned,vbintakevbvalvevbisvb
bent,vborvbcamshaftvblobevbisvbworn.

thevbcustomervbcomplainsvbthatvbthevbenginevbcranksvbbutvbdoesvbnotvbstart;vbthevbfirstvbthi
ngvbtovbcheckvbshouldvbbe

valvevbtrainvboperation,
batteryvbvoltage,
compression,
enginevbvacuum,vb-vbanswer--valvevbtrainvboperation:

,ifvbthevbenginevbcranksvbproperly,vbthevbbatteryvbisvbnotvbthevbproblem.vbCompressionvbwo
uldvbnotvbbevbthevbFIRSTvbtest,vbandvbbecausevbenginevbvacuumvbisvblowvbduringvbavbcrank
,vbavbvacuumvbtestvbwouldvbnotvbbevbconclusive.

duringvbavbcylindervbbalancevbtestvbonvbanvbenginevbwithvbfuelvbinjection,vbonevbcylindervbpr
ovidesvbveryvblittlevbrpmvbdrop.vb
TechvbAvbsaysvbthevbignitionvbsystemvbmayvbbevbmisfiringvbonvbthatvbcylinder.vb
TechvbBvbsaysvbthevbenginevbmayvbhavevbanvbintakevbmanifoldvbvacuumvbleak.

Avbonly,
Bvbonly,
vbAvb&vbB,

Neithervb,vb-vbanswer--BothvbA&B

Bothvbavbmisfiringvbignitionvbsystemvbandvbanvbintakevbmanifoldvbleakvbcouldvbcausevbavbcyl
indervbtovbcontributevbtoovblittlevbpower

whilevbdiscussingvbbasicvbdiagnosticvbprocedures,vb
TechvbAvbsaysvbthevbmostvbcomplicatedvbdiagnosticvbtestsvbshouldvbbevbperformedvbfirst.vb
TechvbBvbsaysvbthatvbyouvbshouldvbfirstvbquestionvbthevbcustomervbtovbobtainvbasvbmuchvbinf
ovbasvbpossiblevbaboutvbthevbproblem

A,
Bvb,
Avb&vbB,
Neither,vb-vbanswer--B

Alwaysvbattemptvbthevbmorevbsimplevbdiagnosisvbfirst

withvbthevbenginevbidling,vbavbvacuumvbgaugevbconnectedvbtovbthevbintakevbmanifoldvbfluct
uatesvb(fromvb15vbtovb20).vbThesevbfluctuationsvbmayvbbevbcausedvbby

latevbignitionvbtiming,
intakevbmanifoldvbvacuumvbleaks,
avbrestrictedvbexhaustvbsystem,
stickyvbvalvevbstemsvbandvbguides,vb-vbanswer--stickyvbvalvevbstemsvbandvbguides


-latevbignitionvbtimingvbwouldvbresultvbinvbavblow,vbsteadyvbreading
-intakevbmanifoldvbleaksvbwouldvbcausevbavbveryvblow,vbsteadyvbreading
-
avbrestrictedvbexhaustvbsystemvbwouldvbcausevbvacuumvbtovbslowlyvbdecreasevbaftervbthevb
enginevbwasvbacceleratedvbandvbheldvbsteady

oilvbisvbleakingvbfromvbthevbcrankshaftvbrearvbmainvbbearingvbsealvbonvbanvbengine.vbTechvb
Avbsaysvbthevboilvbsealvbcouldvbbevbfaulty.vbTechvbBvbsaysvbthevbPCVvbsystemvbmayvbnotvbbe
vbfunctioning.



A,
B,

,Avb&vbB,
Neither,vb-vbanswer--A&B

Avbhigh-
pitchedvbsquealingvbnoisevbisvbheardvbduringvbhardvbacceleration.vbThisvbmayvbbevbthevbca
usevbof:

intakevbmanifoldvbleak,
thevbchokevbstuckvbclosed
fuelvbsystemvbleak
smallvbleakvbinvbexhaustvbmanifoldvb-vbanswer--smallvbleakvbinvbexhaustvbmanifold

-intakevbmanifoldvbleakvbcausesvbavbhigh-pitchedvbwhistlevbatvbidlevbandvblowvbspeeds
-carbvbchokevbstuckvbclosedvbwillvbnotvbcausevbavbhigh-pitchedvbwhistle
-fuelvbsystemvbleakvbnormallyvbwouldvbnotvbcausevbavbnoise

avbheavyvbthumpingvbnoisevboccursvbwithvbthevbenginevbidling,vbbutvbthevboilvbpressurevbisvb
normal.vbthisvbmayvbbevbcausedvbby:

wornvbpistonsvbandvbcylinders,
loosevbflywheelvbbolts,
wormvbmainvbbearings,
loosevbcamshaftvbbearings,vb-vbanswer--loosevbflywheelvbbolts

-wornvbpistonsvbandvbcylindersvbwouldvbcausevbavbthumpingvbnoisevbduringvbacceleration
-wornvbmainvbbearingsvbcausevbavbthumpvbwhenvbthevbenginevbisvbstarted
-loosevbcamshaftvbbearingsvbwouldvbcausevbavbgrowlingvbnoisevbatvballvbtimes

aftervbavbvehiclevbisvbparkedvbovernightvbandvbthenvbstartedvbinvbthevbmorning,vbthevbengine
vbhasvbavbliftervbnoisevbthatvbdisappearsvbaftervbrunningvbforvbavbshortvbtime.vbthisvbmayvbbevb

causedvbby:

lowvboilvbpressure,
lowvboilvblevel,
wornvbliftervbbottom,
excessivevbliftervbleak-down,vb-vbanswer--excessivevbliftervbleak-down

lowvboilvbpressurevbwouldvbresultvbinvbavbcontinuousvbnoise
lowvboilvblevelvbwouldvbresultvbinvbavbcontinuousvbnoise
wornvbliftervbbottomvbwouldvbresultvbinvbavbcontinuousvbnoise

whenvbusingvbavbcompressionvbtester,vbthevbreadingsvbonvbthevbcylindersvbarevballvbeven,vb
butvblowervbthanvbspec.vbthisvbcouldvbindicate:

blownvbheadvbgasket,
carbonvbbuildup,
crackedvbhead,
wornvbringsvbandvbcylinders,vb-vbanswer--wornvbringsvbandvbcylinders

-avblowvbreadingvbonvbtwovbadjacentvbcylindersvbmayvbindicatevbavbblownvbheadvbgasket

, -carbonvbbuildupvbwouldvbcausevbavbhighvbreading
-avblowvbreadingvbonvbtwovbadjacentvbcylindersvbmayvbindicatevbavbcrackedvbhead

avbcylindervbbalancevbtestvbisvbbeingvbperformedvbonvbanvbenginevbtovbdeterminevbwhichvbc
ylindervbisvbcausingvbavbmiss.vb
TechvbAvbsaysvbthatvbwhenvbthevbfaultyvbcylindervbisvbdisabled,vbenginevbrpmvbwillvbdropvbm
orevbthanvbforvbthevbothervbcylinders.vb
TechvbBvbsaysvbdisablingvbthevbfaultyvbcylindervbwillvbcausevbthevbenginevbtovbstall

Avb,
B,
Both,
Neither,vb-vbanswer--Neither

thevbfaultyvbcylindervbwillvbnotvbcausevbthevbenginevbtovbstall,vbneithervbwillvbitvbcausevbthevbe
nginevbtovbdropvbinvbRPMvbsincevbitvbisvbfaulty.

anvbenginevbisvbidlingvbatvb750vbrpm.vbthevbpointervbonvbthevbvacuumvbgaugevbisvbfloatingvbb
etweenvb11vbandvb16vbinvbHg.vbThevbmostvblikelyvbcausevbis

retardedvbtiming,
advancedvbtiming,
stuchvbEGRvbvalve,
toovbleanvbidlevbmixture,vb-vbanswer--toovbleanvbidlevbmixture

allvbothersvbwouldvbnotvbresultvbinvbgaugevbfluctuation

thevbfirstvbstepvbavbTechvbshouldvbtakevbforvbdiagnosisvbis:

thinkvbofvbpossiblevbcausesvbofvbthevbproblem,
questionvbthevbcustomer,
roadvbtestvbthevbvehicle,
listenvbtovbthevbcustomer,vb-vbanswer--listenvbtovbthevbcustomer

thevbcustomervbsaysvbthatvbthevbenginevbrequiresvbexcessivevbcrankingvbtovbstart.vbthevbLE
ASTvblikelyvbcausevbofvbthisvbproblemvbwouldvbbe:

crackedvbcylindervbblock,
jumpedvbtimingvbbelt,
faultyvbfuelvbpump,
stuck-openvbEGRvbvalve,vb-vbanswer--crackedvbcylindervbblock

whichvbofvbthevbfollowingvbisvbLEASTvblikelyvbtovbcausevbenginevbnoise?

loosevbpistons,
wornvbcylinders,
wornvbmainvbbearings,
loosevbcamshaftvbbearings,vb-vbanswer--loosevbcamvbbearings

-loosevbpistonsvbmayvbcausevbavbrappingvbnoisevbwhilevbaccel