Quiz 2

O2 sensor heater failure

A cracked exhaust pipe before the upstream HO2S can cause all of the following except

Tech A

A new engine has just been started for the first time. Tech A says that a mechanical oil pressure gauge should be installed and monitored during this time. Tech B says to let the engine idle until the oil pressure stabilizes and the thermostat opens

Both Techs

A running compression test is being performed. Tech A says a low reading could be caused by a worn camshaft lobe. Tech B says low reading could be caused by an excessively worn lifter.

Valve guide seals

All of the following leaks could affect combustion on a cylinder EXECPT

Shorted IAT sensor

All of the following would most likely cause black smoke to emit from the exhaust pipe except a

Connecting rods

Aluminum is used in the construction of all the following modern production engine components except:

Cylinder power balance test

An engine is idling rough and has a lack of power. Which test should be performed first

Both techs

Compression testing is being discussed. Tech A says that if one cylinder is found to be low, a wet test should be performed to help narrow down the diagnoses. Tech B says that a difference is 10% between cylinders would be acceptable

Both techs

Compression testing is being discussed. Tech A says that the ignition should be disabled. Tech B says that the fuel system should be disabled.

1,500-2,000 rpm

During the initial start up for a rebuilt engine what rpm should the engine be run at for the first 20 min of operation

Pistons

Magna-fluxing can usually be used on all the following components except

using sealants when not necessary, over torquing, uneven tightening

Many new gasket failures are caused by which of the following?

Both Techs

Turbochargers are being discussed. tech A says that the compressor wheel is mounted in the air intake system. Tech B says that boost pressure is limited by the wastegate.

Tech B

Power balance testing is being discussed. Tech A says that during testing, a large drop in rpm indicates a cylinder that is not producing necessary power. Tech B says that on some vehicles, this test can be performed with a scan tool because of factory programming.

Tech A

Removing the engine is being discussed. Tech A says that it is not necessary to remove the air conditioning compressor or refrigerant from some cars. Tech B says that it is not necessary to disconnect or remove the battery

Tech A

Tech A says a vehicles first road test after having a new engine installed is to help the rings to seal. Tech B says several wide open throttle starts will help seal the rings.

Both Techs

Tech A says adding cold water to an overheated engine can cause aluminum cylinder heads to crack. Tech B says casting defects can cause cracks to appear in engine components

Tech A

Tech A says all metals have a grain structure that helps determine the metal's strength. Tech B only ferrous metals have a grain structure.

Both techs

Tech A says leaking valves could cause noticeable popping noises from the engine. Tech B says that preignition can possibly lead to engine damage.

Neither A nor B

Tech A says machined components are stronger than both cast and forged components. Tech B says machined components are less costly to manufacture than forged components.

Both Techs

Tech A says many modern engine use head gaskets that must be retorqued after initial engine operation. Tech B says retorquing is necessary to ensure the correct clamping pressure on the head gasket.

Tech A

Tech A says most sealants have a shelf life of about one year. Tech B says RTV sealant do not have a shelf life and can be used indefinitely after opening

Tech A

Tech A says seals are used to prevent fluid leaks around rotating parts. Tech B says seals are used to prevent leaks between stationary parts.

Tech B

Tech A says that a new engine should be driven steady and allowed to idle as much as possible during the first 500 miles. Tech B says that it is important to have the oil changed after the first 500 miles of use on a rebuilt engine

Both techs

Tech A says that broken vacuum hoses can cause an engine to run lean. Tech B says that vacuum leaks can cause poor fuel economy.

Neither A nor B

Tech A says that engines with multi-port fuel injection use plastic intake manifolds to cool the air-fuel mixture. Tech B says that intake runners that are short and large in diameter are designed for peak power at lower engine rpm.

Both techs

Tech A says that excessive clearance on a rod bearing can cause a knocking sound from the engine bottom end. Tech B says that a cracked flex plate can cause knocking sound from the engine bottom end

Both techs

Tech A says that exhaust leaks can affect the air-fuel mixture of an engine. Tech B says that exhaust leaks can be dangerous for customers driving their car.

Tech A

Tech A says that inadequate engine oil level can damage a turbocharger. Tech B says low engine oil level can cause damage to a supercharger.

Tech A

Tech A says that it is recommended to replace the water pump when installing a new engine unless there is already one installed or the installed or the original one was recently changed. Tech B says that coolant should he reused as long as it was kept clean when it was drained

Both techs

Tech A says that it is unlawful to disconnect the air conditioning hoses and allow the refrigerant to vent out. Tech B says that the power steering pump can be tied off to the side without disconnecting on some cars

Tech A

Tech A says that noise from piston slap usually starts out by making noise when the engine is cold and goes away after it reaches operating temperature. Tech B says that replacing the oil pump will stop the noise created by piston slap

Both techs

Tech A says that some fuel systems are under pressure when the engine is not running. Tech B says that the cooling system should only be dismantled after the engine has cooled down.

Neither A nor B

Tech A says that the air cleaner assembly has a bypass valve that allows air into the engine when the air filter is clogged. Tech B says that most air filters are mounted after the MAF

Tech B

Tech A says that vacuum is high when engine load is high. Tech B says that vacuum is high when an engine is at idle speed and no load.

Neither a nor b

Tech A says that you should remove all of the engine accessories that are still attached to the engine while it is hanging from the engine hoist. Tech B says that when you are bolting the engine up to the engine stand the bolts should thread into the block at least half the thickness of the bolts

Both techs

Tech A says the catalytic converter helps reduce exhaust system noise. Tech B says a catalytic converter may be mounted Into the exhaust manifold.

Tech A

Tech A says to always use new gaskets when transferring oil pans and valve covers from an old engine to a reman engine. Tech B says it is acceptable to reuse gaskets that are in good condition

Neither A nor B

Testing for a restricted exhaust system using a vacuum gauge is being discussed. Tech A says this test should be performed at idle only. Tech B says that high vacuum on the gauge during all phases of the test indicated a restricted exhaust.

They are torque to yield bolts

The cylinder head bolts have been removed from an engine. The manufacturer of the engine requires replacement of these bolts for the installation procedure of the cylinder head, this is because

500 miles

The first oil change after an engine overhaul or replacement should occur at

Tech A

Turbocharges are being discussed. Tech A says that the engine supplies oil to the turbocharger for lubrication. Tech B says that all turbochargers have coolant lines from the engine attached to prevent overheating.

Torque converter bolts

What must be removed if the automatic transmission is not being removed with the engine

On while the key is on and engine off and off while the engine is running

What should the warning indicator for oil pressure do when the ignition key is timed to the run position and then after the engine is started

Pyrometer

What would be best to use when monitoring the temperature of a new engine that has just been started

Thrust bearing

Which engine component is responsible for limiting crankshaft end play

Incorrect valve adjustments

Which of the following is most likely to cause a light tapping or ticking noise from the engine

Sintering

Which of the following is not a metal treatment method?

Applying increased force

Which of the following is not recommend when trying to loosen a stuck fastener?

Cleaning mating surfaces with mineral spirits

Which of the following is not typical for applying a RTV sealant

12 psia

Which of the following would be considered a vacuum at sea level

Worn cam lobe

Which of the following would most likely cause a low running compression reading on one cylinder

Clogged crankcase ventilation filter

Which of the following would most likely cause oil to be found in the air cleaner assembly?

Cylinder leakage test

Which test will most accurately pinpoint the finding of a bad intake valve

open-ended wrench

Which tool should not be used when trying to remove a fastener?

13.5-15.0 volts

While monitoring the charging system during the initial run time of a new engine what voltage should be maintained