Engine Theory, Design, and Diagnosis
One liter equals
1,000 centimetres
The ideal air-fuel mixture for a gasoline engine is:
14.7:1
The best cleaning temperature of a hot-tank solution would be about:
190 F or 88 C
On a 4 stroke engine a complete cycle is of ? crankshaft revolution.
720 deg
A vernier caliper can measure:
All of the above
A car has oil smoke from its exhaust during deceleration. Technician A says that bad valve guide seals could be the cause. Technician B says that worn piston rings could be the cause. Who is right?
Both A and B
A noise occurs at 1/2 crankshaft rpm. Technician A says that this could be a bad lifter. Technician B says that this could be a valve that needs to be adjusted. Who is right?
Both A and B
An engine has a crack between a water jacket and an oil gallery. Technician A says that oil will go into the cooling system when the engine is running. Technician B says that coolant will go into the oil when the engine is off. Who is right?
Both A and B
An engine has late valve timing. Technician A says that this will cause poor low rpm performance. Technician B says that at higher rpm, engine performance might be acceptable. Who is right?
Both A and B
Oil consumption problems are being discussed. Tech A says a lack of regular services can cause the oil control rings to plug. Tech B says worn compression rings can cause oil consumption problems. Who is correct?
Both A and B
Oil leaks are being discussed. Tech A says a blue lamp can be used to locate an oil leak after a dye has been installed in the crankcase. Tech B says that a black light can be used to locate an oil leak. Which tech is correct?
Both A and B
Tech A says a faulty head gasket can cause the oil to appear milky-brown. Tech B says this is called cross fluid contamination. Which tech is correct?
Both A and B
Tech A says that an air-fuel mixture that is too lean can cause burned internal engine parts. Tech B says an overly rich mixture can cause oil wash from cylinder walls. Which tech is correct?
Both A and B
Technician A say that an automatic transmission heat exchanger is often located within the radiator, Technician B says that an automatic transmission heat exchanger is often found in the bottom of a radiator. Who is right?
Both A and B
Technician A says a DOHC V-6 engine has four camshafts. Technician B says temperature of the air & fuel in the cylinder increases as it is compressed. Who is right?
Both A and B
Technician A says an indication of pre-ignition could be a hole burned in the center of a piston. Technician B says detonation is an explosion inside the cylinder that will "break" parts. Which technician is correct?
Both A and B
Technician A says that a bake oven removes rust. Technician B says that a bake oven removes scale. Who is right?
Both A and B
Technician A says that a valve related noise will occur at the same rate of speed as the spark plug firing impulses. Technician B says timing chain wear can sometimes be located by using a stethoscope. Which tech is correct?
Both A and B
Technician A says that an engine that idles rough due to burned valves might run fine at speeds above idle. Technician B says that carbon buildup in a combustion chamber can cause an engine to have higher compression. Who is right?
Both A and B
Technician A says that one revolution of the micrometer thimble equals 1/40 inch. Technician B says that one revolution of the micrometer thimble equals 0.025 inch. Who is right?
Both A and B
Technician A says that some crankshaft sprockets slide easily onto the crankshaft snout. Technician B says that some crankshaft sprockets are pressed fit. Who is right?
Both A and B
Technician A says that some front wheel drive engines have to be removed from the bottom of the vehicle. Technician B says the main caps must be kept in order & in the same direction. Who is right?
Both A and B
Technician A says that the crankshaft turns 720° during one four-stroke cycle. Technician B says that the camshaft turns 360° during one fourstroke cycle. Who is right?
Both A and B
Technician A says that the intake and exhaust valves are both closed during most of the power stroke. Technician B says that the intake and exhaust valves are both closed during most of the compression stroke. Who is right?
Both A and B
Technician A says there is a correct sequence to follow when removing head bolts. Technician B says if an engine has a measurable ridge at the top of a cylinder wall it will require reboring and honing. Which technician is correct?
Both A and B
Technician A says to check the cylinder bores for size, taper, and out-of-round wear. Technician B says to check the crankshaft journals for size, taper, and out-of-round wear. Who is right?
Both A and B
Two technicians are discussing compression test results. Technician A says that abnormally low compression in adjacent (neighboring) cylinders most likely indicates a bad head gasket. Technician B says that if the reading on the compression tester goes up after adding oil to the cylinder, the compression rings are probably worn. Who is right?
Both A and B
Two technicians are discussing shot peening. Technician A says that larger shot hits a part with more impact. Technician B says that parts can be made stronger by shot peening. Who is right?
Both A and B
Two technicians are discussing the part installed on the front of the crankshaft to control its twisting. Technician A says that it is called a harmonic balancer. Technician B says that it is called a vibration damper. Who is right?
Both A and B
A base is very acidic. True or false?
False
A compression test can be used to diagnose a seized engine.
False
A four stroke engine uses a "reed valve" to trap air & fuel in the cylinder.
False
A two stroke engine has a power stroke every other crankshaft revolution.
False
An "F" head engine is simple, compact and easy to repair.
False
An EC engine is typically found in newer trucks.
False
An OHV V-6 engine has 2 camshafts.
False
In an "I" head engine, the valves are in the block.
False
Oil consumption is always due to faulty piston rings.
False
The 10th digit of the vin code will identify the engine size.
False
To diagnose an engine with a misfire, the first test should be a cylinder leakage test.
False
Tech A says the ring ridge reamer does not need to be used if the pistons come out of the block easily. Tech B says the ring ridge is a result of carbon deposits on the cylinder wall. Who is right?
Neither A or B
Technician A says that the purpose of the flywheel is to control the twisting of the crankshaft. Technician B says that the purpose of the vibration damper is to help provide a continuous flow of power. Who is right?
Neither A or B
Technician A says that "blowby" consists of gases that leak past the valves. Technician B says that blowby reduces the pressure in the crankcase. Who is right?
Neither A or B
Technician A says that a gauge block is used to measure valve lash (clearance). Technician B says that the vernier scale on a micrometer measures to 0.001". Who is right?
Neither A or B
Technician A says that it is usually easier to remove the engine with the automatic transmission on a rear-wheel drive car. Technician B says to disconnect the positive battery cable first. Who is right?
Neither A or B
Technician A says that with a vacuum leak, an engine with an oxygen sensor feedback fuel system can run fine when cold but rough when hot. Technician B says that advanced ignition timing will often cause an engine to run hot. Who is right?
Neither A or B
Technician A says the only difference between "SI" engines and "CI" engines are their fuels. Technician B says when cylinder #1 is at TDC you must turn the crankshaft 720deg before its companion cylinder comes to TDC. Who is right?
Neither A or B
Technician A says to correctly identify a vehicle all you need to know is the make and model. Technician B says the VIN code can be found in the owners manual. Who is correct?
Neither A or B
Two technicians are discussing cleaning solvents. Technician A says that it is not necessary to use gloves with petroleum-based solvents. Technician B says that most new cleaning solvents are chlorinated. Who is right?
Neither A or B
Diesel engine spark plugs should be changed every ? miles
None
Tech A says that the Otto cycle gasoline engine has four strokes per cycle. Tech B says that the crankshaft makes four revolutions during the four stroke cycle. Who is right
Tech A Only
A six-cylinder engine has a 1 5 3 6 2 4 firing order. Technician A says that after cylinder number 1 begins its intake stroke, the crankshaft will have to travel 240° before cylinder number 3 begins its intake stroke. Technician B says that when cylinders number 3 and 4 are at TDC, cylinders number 5 and 2 are at BDC. Who is right?
Tech A only
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 a running compression test should be about 1/4 that of a cranking compression test. Which technician is correct?
Tech A only
Technician A says "valve overlap" occurs while the piston is at the top of the cylinder. Technician B says when there is not enough air in the air/fuel mixture it is called a "lean" condition. Who is right?
Tech A only
Technician A says a stoichiometric mixture is ideal for the performance, emissions and economy of an engine. Technician B says a lean mixture can be caused by a dirty air filter. Who is correct?
Tech A only
Technician A says atmospheric pressure is 14.7 psi at sea level. Technician B says it is easier for the engine to pump air in the mountains. Who is right?
Tech A only
Technician A says that a cylinder leakage test is better than a compression test for testing the condition of an engine before installing it in a car. Technician B says that a compression tester is better than a cylinder leakage tester for testing the condition of an engine with a performance camshaft. Who is right?
Tech A only
Technician A says that an in-line six-cylinder engine is Usually longer and heavier than a V8 engine of the same displacement. Technician B says that there are twice as many teeth on the crankshaft sprocket as there are on the camshaft sprocket. Who is right?
Tech A only
Technician A says that diesel engines have compression ratios that are about twice as high as those found in gas engines. Technician B says that diesel engines require less maintenance than gasoline engines. Who is right?
Tech A only
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 there is no need to keep bearings in order if new parts are to be used. Which technician is correct?
Tech A only
Technician A says that one reason all main and rod bearings should be kept in order during engine disassembly is 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?
Tech A only
Technician A says that steam cleaning and pressure washing are common methods of cleaning internal engine parts. Technician B says that steam cleaning is safe to use with electrical components. Who is right?
Tech A only
Technician A says that steel shot blasting is commonly used to clean ferrous parts, Technician B says that steel shot blasting is commonly used to clean aluminum parts. Who is right?
Tech A only
Technician A says that vacuum readings for an engine with a performance camshaft might be lower at idle. Technician B says that an engine that has worn lower main bearings will have lower oil pressure at freeway speeds. Who is right?
Tech A only
Technician A says that when using a flare-nut wrench, two wrenches must often be used. Technician B says to use an open-end wrench on fuel fittings. Who is right?
Tech A only
Technician A says the I-head engine is widely used in automobiles because it can breathe better than an L-head engine. Technician B says that an L-head engine can make more power and have lower emissions than would be possible for an I-head engine. Which tech is correct?
Tech A only
Technician A says to use an air impact wrench to remove rusted exhaust nuts. Technician B says that when installing a flywheel ring gear, heat it until it is red hot. Who is right?
Tech A only
Technician A says to verify camshaft timing before engine disassembly. Technician B says roller lifters may not be reused if they are not kept in order during disassembly. Who is correct?
Tech A only
An eight-cylinder engine has a 1 8 4 3 6 5 72 firing order. Technician A says that cylinder number 3 is cylinder number 1's companion. Technician B says that cylinder number 5 is cylinder number 8's companion. Who is right?
Tech B only
Tech A says to disconnect the air conditioning lines and drain the refrigerant into a pan. Tech B says R-134A has to be recovered with a special machine.Who is right?
Tech B only
Technician A says that a compression test can be used to check the condition of the oil control rings. Technician B says that when several cylinders have low compression test readings, this can be due to burned or tight valves. Who is right?
Tech B only
Technician A says that a freewheeling engine is one that does not slow the vehicle down when decelerating. Technician B says that a freewheeling engine is one in which the valves cannot contact the pistons if the timing chain or belt breaks. Who is right?
Tech B only
Technician A says that cylinder heads are more easily removed after warming up the engine. Technician B says that to avoid warping the head, the engine must be cold before removing it. Who is right?
Tech B only
Technician A says that fuel deposits are gummy. Technician B says fuel deposits can be white and look flaky. Who is correct?
Tech B only
Technician A says that the vibration damper is removed with a puller that grasps the damper's outer ring. Technician B says that when an air impact wrench is used on a puller to remove the vibration damper, the crankshaft need not be kept from turning. Who is right?
Tech B only
Technician A says to use a ball peen hammer on the rod bolts to loosen the rod caps for easy removal. Technician B says to remove the core plugs before. hot tanking the block. Which technician is correct?
Tech B only
The metric measuring system is based on:
The number 10
A power balance test can used to locate a misfire.
True
A rich air-fuel mixture could cause a catalytic converter to plug up.
True
An infrared analyzer can be used to check the radiator for combustion leaks.
True
Before an engine can make any power it must first pump air.
True
Excessive clearance at a rod bearing journal will cause a "rod knock".
True
If an engine will not turn over in either direction, it could be due to a broken crankshaft.
True
If the temperature of a cleaning liquid is too low, cleaning time will be longer. True or false?
True
Lubricate all ferrous parts to prevent rust following hot-tank cleaning. True or false?
True
Remove all oll gallery plugs and clean oll galleries with a brush following hot-tank cleaning. True or false?
True
The VIN code will identify the year that the vehicle was produced.
True
The camshaft controls the way the engine breathes.
True
The engine should be cold before removing the head.
True
The gasoline engine is also known as a SI engine.
True
