Internal Combustion Engine Final
Technician A says that a tap is used to cut new threads or repair damaged threads on a bolt. Technician B says that a die is used to cut new threads or repair damaged threads on a nut or in a hole. Who is correct?
Neither
Technician A says that overhead cam engines usually have pushrods. Technician B says that overhead cam engines do not have lifters. Who is correct?
Neither
Technician A says that the size of the bolt is the size of the wrench that is used to remove or install it. Technician B says that the length of the bolt is measured from the top of the head of the bolt to the end of the bolt. Who is correct?
Neither
Which product requires heat to remove?
Red thread locker
Which of the following practices is NOT advisable?
Remove all "freeze" plugs from the cylinder head so that you can clean it
When removing bolts, what order should they typically be removed in?
Reverse of the recommended tightening sequence
A screw that can make its own threads when installed is called a _____________ screw
Self-tapping
Which of the following statements about service information is NOT true?
Since all sources will have the same TSB's, it is only necessary to use one source to find bulletins
Why is it so important that all engine components are marked and labeled clearly before disassembly?
So that if any components are reused, they can be installed in their original position and direction
A one-piece oil pan gasket often uses ____________ in the middle to add strength.
Steel
The distance between TDC and BDC is referred to as the :
Stroke
Why is it recommended that you place a piece of plywood in front of the radiator and AC condenser?
To protect the radiator and condenser from getting damaged by other components or tools
The amount of rotational force that an engine produces is called:
Torque
Magnetic Crack detection:
Uses a fine iron powder to detect cracks in iron parts
The most recommended way to clean the surface of a cylinder head or engine block deck is:
Using a flat sander with a fine-grit sandpaper
In a typical lubrication system, what components are the last to receive oil and the first to suffer from a lack of oil or oil pressure?
Valve train components
Which of the following parts should be numbered BEFORE they are removed from the engine? (Choose all that apply)
connecting rods connecting rod bearing caps main bearing caps
A long block can be made from a short block with the addition of ________________
cylinder heads and valve train
If a pyrolytic oven is used to clean parts, caution should be used to limit the temperature. What is the recommended MAXIMUM temperature?
600 degrees F for aluminum parts and 800 degrees F for cast iron parts
One cylinder of an automotive four-stroke engine completes its four-stroke cycle every:
720 degrees
During a cylinder leakage test, bubbles are seen in the radiator, which of the following could cause this?
A leaking head gasket
A bolt with three lines on the head is
A standard grade 5 bolt
To measure the flatness of a cylinder head surface or a block deck surface, which tool(s) should be used?
A straight-edge and a feeler gauge
A steel or copper wire used in a head gasket to seal the combustion chamber is called:
Fire ring or armor
Which of the following components is NOT found on a car with an automatic transmission?
Flywheel
A gasket failure caused by the movement of dissimilar metals is called:
Fretting
All of the following statements about camshaft lobe lift are true EXCEPT:
It is a measurement of the diameter, taper and out-of-round of the camshaft journals
Which of the following statements is FALSE?
It is acceptable to use red threadlocker on most fasteners
Which of the following is true regarding a relative compression test (choose all that apply)
It lets you know how the compression of each cylinder compares to the compression of the other cylinders It cannot give you an actual compression reading It is a very quick way to check for mechanical engine problems that affect some of the cylinders
If the four corners of a piston are scuffed, what likely happened to the engine?
It overheated
Which of the following would be considered "excessive" oil consumption according to most manufacturer's specifications? (Choose all that apply)
1 quart every 250 miles 1/2 quart every 250 miles
Normal oil pump pressure in an engine is ________
10-60 psi
Normal engine vacuum at idle in Rexburg (4850 feet above sea level) should be:
12-16 in. Hg.
A SOHC V-8 engine has how many camshafts?
2
All safety glasses should meet the standards set by
ANSI
Which of the following statements is true?
After a bolt's yield limit has been reached, the clamping force still continues to increase
A good reading for a cylinder leakage test would be:
All cylinders below 20% leakage
Abrasive pads or discs should be used_________________.
All of the above
To determine if a product or substance being used is hazardous, consult
An MSDS
When jump-starting a vehicle, the negative cable should be connected last, and should be connected to the engine block rather than the battery terminal in order to prevent:
An explosion
Which of the following is recommended for use on exhaust manifold bolts, studs or nuts?
Antiseize compound
Which of the following statements is true about removing bolts from a manifold, cylinder head, or cover? (Choose all that apply)
Bolts should be removed in the opposite order of their tightening sequenceNone of the above is correct
Lower than specified oil pressure is measured on an engine. Technician A says that worn rod or main bearings could cause this. Technician B says that a clogged oil pump pick-up screen could cause this. Who is correct?
Both
Technician A says that crankshaft end-play can be measured with a dial indicator. Technician B says that crankshaft end-play can be measured with a feeler gauge. Who is correct?
Both
Technician A says that for accurate bolt tightening, the threads of the bolt must be cleaned before installation. Technician B says that all bolts should be tightened using a torque wrench. Who is correct?
Both
Technician A says that nitrile gloves will prevent toxins from entering your body through your hands. Technician B says that nitrile gloves can prevent minor cuts and scrapes. Who is correct?
Both A and B
If an engine is making a noise that sounds like a rod knock, how can this be verified and narrowed down to a specific connecting rod?
By disabling the spark to each cylinder, one at a time, to see if the knock sound decreases
Most engines (except some Hondas) rotate in a ______________ direction as viewed from the harmonic balancer.
Clockwise
A "block tester" is used to detect:
Combustion gases leaking in to the coolant
An engine oil cooler uses what to cool the oil?
Coolant
What stroke of the engine precedes the intake stroke?
Exhaust
Which measuring tool needs to be set up (adjusted) to a fixed dimension before it can be used?
Dial Bore Gauge
Grooves or lines worn into a bearing or journal indicate:
Dirt or debris in the engine oil
The dangers of wearing a ring while working in a lab or shop include:
Electrical Burns Getting the ring caught in moving parts Both of the above answers
The horsepower of an engine cannot be measured directly. It is calculated based on the __________ and the ___________.
Engine Speed; Torque
The part of the engine usually referred to as the combustion chamber is found:
In the cylinder head
Why is a dry-sump system used in some high performance engines?
It allows the vehicle to corner or brake for long periods
Which of the following tools is considered more accurate and should be used for measuring pistons, journals, valves, and other precision components?
Micrometer
The threads of a bolt are measured in what units?
Millimeters Threads per inch Both A and B
Which of the following statements about main and rod bearings is true? (Choose all that apply)
NO - A rod bearing fits between the main journal and the connecting rod bore A main bearing fits between the main journal and the connecting rod bore
A journal is a part that is found on which of the following engine components? (choose all that apply)
NO - Connecting Rod Crank Shaft
Which of the following problems can be detected by a running compression test that would not likely be detected by a cranking compression test? (Choose all that apply)
NO - 1/2 A worn camshaft lobe
If an engine at sea level produces 100 horsepower, it produce about _________ horse power in Rexburg, Idaho (approximately 5000 feet above sea level).
NO- 75 60
Hearing protection should be worn anytime the noise level exceeds
NO- 80 dB 70 dB
Which of the following is not a benefit of AERA membership?
NO- Access to a technical hotline Access to service bulletins that are not available otherwise
When determining that an engine has failed, you should be careful not to base your diagnosis on questionable test information. Which of the following tests and results most concretely shows that the engine needs to be repaired?
NO- An idling vacuum gauge reading that is far below specifications A cylinder leakage of 45% on some of the cylinders
Which of the following statements is true?
NO- Anaerobic sealers will dry out if the lid is left off RTV silicone is a non-hardening sealer
On a longitudinally mounted engine, the left side of the engine is going to be on the:
NO- Back of the engine compartment Front of the engine compartment
If the firing ring of a head gasket appears to be flattened or mis-shaped, what is the likely cause of this?
NO- Burning oil Overheating
Which of the following statements is true?
NO- Pinging and Detonation are two names for the same thing Pinging or pre-ignition is often caused by using a gasoline with an octane rating that is too high
Technician A says that you should typically check for cracks before cleaning, so that you can determine if the part is usable first. Technician B says that a thorough cleaning is not necessary during the inspection stage of an engine rebuild. Who is correct?
NO- Tech A
A burned exhaust valve occurs when:
NO- There is too much blowby The valve stem seals wear out
A cylinder or journal should be measured in at least ____________ places in order to determine its diameter, taper, and out-of round.
NO- Two Three
Which of the following is not considered a hazardous substance that must be disposed of according to regulations?
NO- Used engine oil Used brake fluid
Which of the following measurements require the use of a feeler gauge? (Choose all that apply)
NO- Valve guide clearance Piston ring end gap
Which of the following tools can be used to measure valve guide clearance? (Choose all that apply)
NO- dial bore gauge feeler gauge
Which of the following is a potential cause of excessive oil consumption? (Choose all that apply)
NO- 1/3 Worn oil control rings Worn valve guides and seals Excessive oil pressure
Which of the following statements is true regarding the use of shot or glass bead blasters? (choose all that apply)
NO- 2/3 The part should be cleaned after blasting Parts with small areas that could trap beads should not be blasted Blasting is a safe way to clean the precision machined surface of a component
If an oil gallery feeds one of the main bearings becomes clogged, which of the following could result from this? (Choose all that apply)
NO- 2/3 A crankshaft main bearing would be damaged A single cylinder's walls and piston skirts would be damagaed All of the main bearings would be damaged
A smoothly operating engine depends on:
Nearly equal compression between all cylinders
What precautions should be followed when using gaskets? (Choose all that apply)
Never reuse an old gasket Always check to ensure that you are using the correct gasket
Many cleaning methods involve chemicals that are hazardous to use. The least hazardous method is generally considered to be:
Pyrolytic oven
Which type of sealer is recommended for non-machined surfaces?
RTV
Which of the following are recommended procedures while removing and disassembling an engine? (Choose all that apply)
Take many pictures from many angles, during and after each step of the process Use all four bolts when mounting the engine to an engine stand Carefully inspect every part as you remove it from the engine, looking for signs of wear or damage
Technician A says that a crankshaft determines the stroke of an engine. Technician B says that the length of the connecting rod affects the stroke of an engine. Who is correct?
Tech A
Technician A says that oil pressure is usually lower at idle than at higher RPM. Technician B says that if the oil drainback holes become clogged that oil pressure will increase. Who is correct?
Tech A
Technician A says that when a chain is used to lift an engine, it should be attached to the engine with a bolt that clamps it tightly against the engine. Technician B says that as long as at least 2-3 threads on the bolts are inside the engine, it is safe to lift the engine with a chain. Who is correct?
Tech A
Technician A says that during a power balance test, the cylinder that causes the biggest RPM drop is the weak cylinder. Technician B says that if one spark plug wire is grounded out and the engine speed does not drop, a weak or misfiring cylinder is indicated. Which technician is correct?
Tech B
While discussing engine removal from the vehicle, technician A says that you should leave all plastic sensors and components on the engine until the engine is mounted on the stand. Technician B says that you should support the transmission while removing the engine. Who is correct?
Tech B
If a component is measured and found to be out-of- round, what does this mean?
That it has a larger diameter in one direction than it does in another direction.
If a bolt has an 8.8 stamped on it, what does this tell you about the bolt?
That it is a class 8 metric bolt with a yield strength that is 80% of its tensile strength
The most important sealing job in the engine is performed by:
The head gasket
If the oil pressure regulator valve gets sticks and oil pressure increases, which of the following will be the most likely result?
The oil filter will burst
Engine size is determined by:
The volume that is displaced by the pistons as they travel up and down in the cylinder
When is a cranking compression test preferred over a running compression test
When the car will crank but won't start
When should safety glasses be worn (Choose all that apply)
When using a grinder When using a screwdriver When using a hammer When using a pair of pilers
The "W" in SAE 5W-20 means:
Winter
Some gaskets use a steel washer around each bolt hole. The purpose of this washer is to:
prevent the gasket from being overly compressed
Modern gaskets are usually made of:
silicone rubber
When removing a harmonic balancer, you should:
use a puller that grabs the inner ring of the pulley