Engine Repair Midterm

Which of the following statements is not true about thermal cleaning?

After a part has been thermally cleaned, it should be submerged in water to cool it quickly.

After installing cam bearings: Technician A checks that the oil holes in the bearings are properly aligned with those in the block by squirting oil into the holes. Technician B checks for proper alignment by inserting a wire through the holes. Who is correct?

Both A and B

After removing the vehicle's hood in preparation for removing the engine: Technician A places the hood on the roof of the vehicle. Technician B sets the hood aside in a safe place on fender covers or cardboard. Who is correct?

Both A and B

Technician A labels or marks all electrical wires before disconnecting them. Technician B labels or marks all vacuum hoses and verifies the connections to the underhood decal before disconnecting them. Who is correct?

Both A and B

Technician A says head gasket thickness has an effect on compression ratio. Technician B says connecting rod length has an effect on compression ratio. Who is correct?

Both A and B

Technician A says that a cylinder wall with too smooth a surface will prevent the piston rings from seating properly. Technician B says that a cylinder wall should have a crosshatch honing pattern. Who is correct?

Both A and B

Technician A uses a crane to remove an engine from its compartment. Technician B uses an engine cradle to remove an engine from its compartment. Who is correct?

Both A and B

Technician A uses a feeler gauge and straightedge to determine the pump cover flatness. Technician B uses an outside micrometer to measure the diameter and thickness of the outer rotor. Who is correct?

Both A and B

Technician A uses a micrometer to measure the connecting rod journal for taper. Technician B uses a micrometer to measure the connecting rod journal for out-of-roundness. Who is correct?

Both A and B

Which type of oil ring is slotted so that excess oil can pass through it?

Both A and B

While discussing the common causes for cracks developing in a cylinder block or head: Technician A says that the chilling of a hot engine by a sudden rush of cold water or air over the surface may cause cracking. Technician B says that excessive overheating is a common cause. Who is correct?

Both A and B

While looking at the results of an oil pressure test: Technician A says that higher than normal readings can be caused by using an incorrect viscosity oil. Technician B says that higher than normal readings can be expected on a cold engine. Who is correct?

Both A and B

While loosening the axle shaft hub nuts on an FWD vehicle: Technician A says that a large breaker bar should be used to prevent damage to the bearings. Technician B says that these nuts should be loosened with the vehicle on the floor and the brakes applied. Who is correct?

Both A and B

While working on an engine with an excessive amount of sludge buildup: Technician A says that the presence of sludge is a signal to look for wear on other components. Technician B says that excessive buildup can indicate a poor maintenance schedule. Who is correct?

Both A and B

Each half of a split bearing is made slightly larger than an exact half. What is this called?

Crush

Which of the following is not a true statement about diesel engines?

Diesel engines rely on glow plugs instead of spark plugs to initiate ignition.

Which stroke in the four-stroke cycle begins as the piston reaches BDC after combustion takes place?

Exhaust stroke

In an HCCI engine, combustion immediately and simultaneously produces a steady flame across the mixture.

False

On many FWD vehicles, the suspension system must be partially disassembled to remove the radiator.

False

SAE mandates that the engine, when viewed from the front, will be rotating in a counterclockwise direction.

False

The camshaft is always located in the engine block.

False

The first step in removing an engine is usually the removal of the intake and exhaust manifolds.

False

What is the best way to lift a vehicle when preparing to remove an engine?

Frame contact hoist

Cam bearings in OHV engines are typically which type?

Full-round

Which of the following is not of concern when checking a piston?

Groove wear

Technician A checks crankshaft oil clearance with a feeler gauge. Technician B uses a dial indicator to check crankshaft oil clearance. Who is correct?

Neither A nor B

Technician A says that if an engine had good results from a compression test, it will have good results from a cylinder leakage test. Technician B says that if an engine had good results from a cylinder leakage test, it will have good results from a running compression test. Who is correct?

Neither A nor B

Technician A says that piston ring end gaps should be the same for each ring on a piston. Technician B says that piston ring end gaps should be aligned before installing the piston into its bore. Who is correct?

Neither A nor B

When a customer states that black exhaust smoke is coming from the exhaust: Technician A says faulty oil rings may be the cause. Technician B says a faulty head gasket may be the cause. Who is correct?

Neither A nor B

While diagnosing the cause for blue smoke from the tailpipe of a gasoline engine: Technician A says that a faulty fuel injection system is a likely cause. Technician B says that it is most likely caused by coolant leaking into the combustion chamber. Who is correct?

Neither A nor B

While discussing abrasive cleaners: Technician A says that shot is angular in shape and is used for aggressive cleaning. Technician B says that grit is an angular-shaped media and is used to peen metal surfaces. Who is correct?

Neither A nor B

While preparing to remove an engine: Technician A turns the crankshaft pulley to set the engine at number 1 cylinder TDC. Technician B removes the drive belt and crankshaft pulley. Who is correct?

Neither A nor B

Which of the following statements about engines is not true?

Only gasoline engines are classified as internal combustion.

Which of the following is not considered part of the organic soil grouping?

Rust that is a product of coolant and aluminum

A vehicle is producing a sharp, metallic rapping sound originating in the upper portion of the engine. It is most noticeable during idle. Technician A diagnoses the problem as piston pin knock. Technician B says that the problem is most likely a loose crankshaft thrust bearing. Who is correct?

Technician A

Technician A installs a cup-type core plug with its flanged edge outward. Technician B installs a dish-type core plug with the dished side facing inward. Who is correct?

Technician A

Technician A says that crankshaft counterweights offset the weight of the connecting rods and pistons. Technician B says that crankshaft counterweights are used to dampen crankshaft torsional vibrations. Who is correct?

Technician A

When removing the balance shaft assembly: Technician A inspects the bearings for unusual wear or damage. Technician B smoothens a damaged camshaft or balance shaft journal by lightly sanding it. Who is correct?

Technician A

While determining the cause for air leaking out of the oil throttle body during a cylinder leakage test: Technician A says that a burnt intake valve is indicated. Technician B says that a warped cylinder head or bad head gasket is indicated. Who is correct?

Technician A

While determining the most likely problem of an engine with poor compression test results but acceptable cylinder leakage readings: Technician A says that the problem may be incorrect valve timing. Technician B says that the problem is worn valve seats. Who is correct?

Technician A

While discussing cleaning engine parts: Technician A says that the cleaning method used depends on the component to be cleaned and the type of cleaning equipment available. Technician B says a parts tumbler is good for cleaning aluminum components such as intake manifolds and cylinder heads. Who is correct?

Technician A

While removing a cylinder head: Technician A keeps all rocker arms and pushrods in order. Technician B loosens each head bolt, starting with the center bolts and moving toward the ends. Who is correct?

Technician A

When removing the piston and rod assemblies from a cylinder block: Technician A positions the throw of the crankshaft at the top of its stroke and removes the connecting rod nuts and cap. Technician B covers the rod bolts with protectors and pushes the piston and rod assembly out with the wooden hammer handle or wooden drift and supports the piston as it comes out of the cylinder. Who is correct?

Technician B

While conducting an engine vacuum test: Technician A says that a steady low vacuum reading can be caused by a burned intake valve. Technician B says that an overall low vacuum reading is caused by something that affects all of the engine's cylinders. Who is correct?

Technician B

While diagnosing the cause for an engine having good results from a compression test and cylinder leakage test but poor results from a cylinder power balance test: Technician A says that incorrect valve timing is the most likely cause. Technician B says that a severely worn cam lobe is a likely cause. Who is correct?

Technician B

While discussing piston slap: Technician A says that it is a high-pitched clicking that becomes louder during deceleration caused by detonation. Technician B says that it is the noise made by the piston when it contacts the cylinder wall due to excessive clearances. Who is correct?

Technician B

Which of the following is an expression of how much of the heat formed during the combustion process is available as power from the engine?

Thermal efficiency

Many engines in FWD vehicles must be removed with the transmission still attached.

True

Which cleaning method uses high-frequency sound waves to create microscopic bubbles that loosen dirt from parts?

Ultrasonic

Which of the following is not a common way to identify the location of cracks in the engine block or cylinder head?

Vacuum test

Which of the following are not typically found in the block of a modern engine?

Valves

Which of the following statements is not true?

When removing an engine from a RWD vehicle, suspension disassembly is often required.

Most pistons used today are made of ___.

aluminum

Hydrocarbon solvents are ___ .

both A and B

Parts must be ___ when they go into an abrasive blast machine.

both b and c

The connecting rod journal is also called the ___.

crankpin

An engine block should be mounted to an engine stand using a minimum of ___ bolts.

four

All of the following are functions of the flywheel, except it ___ .

has marks used to set the valve timing

The buildup of minerals and deposits inside the cooling system is called ___.

scale

The stroke of an engine is the ___ crank throw.

twice