AED&R pre test Flashcards
Two technicians are discussing “blowby.” Technician A says that “blowby” is gases escaping past the valves. Technician B says that “blowby” is gases escaping past the rings. Which technician is correct?
Technician B
Excessive clearance at a connecting rod bearing journal will cause a rod knock.
True
Technician A says aluminum heads can be checked for cracks with a process known as magnafluxing. Technician B says a red dye penetrant can be used to check for cracks on cast iron heads. Which technician is correct?
?
During a compression test, a cylinder shows lower readings than expected. Technician A squirts a tablespoon of oil into the cylinder and the compression raises. He says this indicates a problem with the rings. Technician B says this indicates a burned intake valve. Which technician is correct?
Technician A
Valves will contract as they warm up during use.
False
All of the following are timing components EXCEPT _____.
?
Technician A says that for each pound of pressure on the cooling system, the boiling point raises one degree Fahrenheit. Technician B says engine rebuilders epoxy heat tabs to the cylinder heads to protect against dishonest warranty claims. Who is correct?
Technician B
What instrument can determine the coolant’s conductivity?
?
The tenth digit of the VIN code will identify the engine size.
False
Oil is being discussed. Technician A says oil never wears out. Technician B says there are many additives in oil that will become depleted during engine operation. Who is correct?
?
A thermostat is installed with its temperature bulb facing the radiator.
False
Springs that have been overheated will stretch and be longer.
False
Technician A says a windage tray helps to keep air pockets out of the oil at high speeds. Technician B says the lubrication system should be primed before starting an engine that has just been rebuilt. Who is right?
Both technicians
Of the measuring devices listed below, which is the most accurate in measuring cylinder bore size?
cylinder dial bore gauge
An engine has excessive valve guide wear Technician A says to ream the guide and install a new valve with an oversize stem.
Technician B says to knurl the valve stem and reinstall it into the guide. Who is correct?
?
Automobile piston pins are either pressed fit or full floating.
True
Technician A says springs should be tested for squareness, tension, and height. Technician B says to stack shims under a valve spring until the spring pressure is correct. Who is correct?
?
Technician A says that basket-type coil springs are installed with the tighter part of the coil against the head. Technician B says grinding a valve seat will not affect the installed height of the valve spring. Who is correct?
?
Technician A says that the top compression ring groove wears more than the other ring grooves. Technician B says that full floating, piston pin lock rings should be installed with their openings facing up. Who is correct?
?
Piston rings are made from all these materials, EXCEPT _____.
?
Technician A says powder forged rods are not cut; they are fractured (broken). Technician B says some rods have a spit hole to lubricate the cylinder walls at lower rpms. Who is right?
?
Technician A says that before a valve guide can be repaired, the valve seat should always be ground. Technician B says the exhaust and intake valves each operate on a separate lobe on the camshaft. Who is correct?
?
Modern day engines can have _____ valves per cylinder.
?
The engine should be cold before removing the head.
True
Turbochargers are driven by _____.
exhaust flow
An engine with a turbocharger is a normally aspirated engine.
False
Viscosity is a term used to describe the thickness or body of engine oil.
True
Technician A says to label the core plugs as they are removed so they can be reinstalled. Technician B says to remove the core plugs before hot tanking the block. Who is correct?
Technician B
Technician A says aluminum heads usually have an aluminum shim beneath the valve spring. Technician B says as the valves are removed from the head, they should be kept in order. Who is correct?
?
An oil is rated at 10W-40. The “W” means winter grade.
True
Cam-in-block engines use pushrods to transmit motion from the lifters to the rocker arms.
True
The camshaft controls the rate at which the engine breathes.
True
Technician A says there is no need to lubricate the valve stems upon reassembly. Technician B says intake and exhaust seals are the same materials and shapes. Who is correct?
?
Technician A says that most automotive gasoline engines have four strokes per cycle. Technician B says that the crankshaft makes four revolutions during the four-stroke cycle. Which technician is correct?
?
Water pumps are sometimes driven by the timing belt.
True
A 30% water and 70% antifreeze is the maximum mixture that should be used.
True
After glaze breaking or cylinder honing, clean the block with _____.
?
Undersize bearings have a thinner bearing back.
False
What cylinder number is the closest to the front of the engine on almost all V-type engines?
1
Technician A says most manufacturers recommend a minimum of 25 psi of oil pressure for every 1000 rpm. Technician B says short trips allow sludge to accumulate. Who is right?
?
Technician A says a piston usually has a direction identifying notch that faces the rear of the engine. Technician B says a piston exhibits more wear on its major thrust side. Who is right?
Technician B
Technician A says a faulty head gasket can cause the oil to mix with coolant. Technician B says bubbles forming in the coolant during engine operation could indicate a leaking head gasket. Which technician is correct?
?
Technician A says that during engine disassembly, all main and rod bearings should be kept in order in case they will be reused. Technician B says that there is no need to keep bearings in order if new parts are to be used. Who is right?
?
Technician A says a mushroomed valve can be driven out with a punch and a hammer. Technician B says the mushroomed tip must be dressed with a file before the valve can be removed. Who is right?
Technician B
Technician A says valve overlap occurs at the bottom of the intake stroke. Technician B says valve overlap occurs at the top of the intake stroke. Who is correct?
Technician B
How many degrees of crankshaft rotation is a complete cycle of a four stroke engine?
?
Technician A says on a flat tappet engine, the lifters do not need to be replaced when the camshaft is replaced. Technician B says when replacing a roller camshaft, the lifters must be replaced. Who is correct?
Neither technician
Excessive clearance at a main bearing will result in low oil pressure at the rocker arms or valve lifters.
True
Two factors of cam lobe profile are called lift and length.
False
Another term for mechanical lifter is tappet.
True
