AUT111 Final Exam
Technician A says atmospheric pressure decreases as altitude increases. Technician B says atmospheric pressure increases as altitude increases. Who is correct?
A only
The rocker arms on a pushrod engine have a 1.5:1 ratio. That means that
A cam lift of .250 inch will cause the valve to open .375 inch
A car has come into a shop with an engine misfire. A power balance test has been performed with the following results. Cylinders 1 2 3 4 RPM Drop 10 150 145 155 Technician A says that cylinder 1 may have low compression. Technician B says that cylinders 2-3-4 are not working properly. Who is correct?
A only
All lifters in an OHV engine are concave. Technician A says that the camshaft and lifters must be replace. Technician B says that the rocker arms must be replaced to return correct lifter preload. Who is correct?
A only
Technician A says compression rings should never be installed by spiraling them onto the piston. Technician B says the top compression ring should be installed on the piston first. Who is correct?
A only
Technician A says that freewheeling engines are not in danger of valve damage due to a broken timing component. Technician B says that balance shafts do not need to be timed to the crankshaft. Who is correct?
A only
Technician A says that improper valve timing can affect cylinder compression. Technician B says that a timing belt that is off by one tooth can affect valve lift. Who is correct?
A only
Technician A says that valve stem height is measured from the valve spring seat to the valve stem tip. Technician B says that incorrect valve stem height causes excessive oil consumption through the valve guides. Who is correct?
A only
Technician A says that when measuring piston ring groove to ring clearance, A feeler gauge should be used. Technician B says that the ring groove clearance should be checked with the ring in the cylinder bore. who is correct?
A only
When measuring valve springs, Technician A says the valve spring must be rotated while measuring squareness. Technician B says that spring squareness can be checked by rolling the spring on a surface plate. Who is correct?
A only
Technician A says worn valve stem seals may cause rapid valve stem and guide wear. Technician B says worn valve stem seals may cause excessive oil consumption. Who is correct?
B Only
Power balance testing is being discussed. Technician A says that during testing, a large drop in rpm indicates a cylinder that is not producing necessary power. Technician B says that on some vehicles, this test can be performed with a scan tool because of factory programing. Who is correct?
B only
Technician A says hydraulic valve lifter bottoms should be flat or concave. Technician B says too tight valve clearance may cause a burned exhaust valve. Who is correct?
B only
Technician A says that a press fit harmonic balancer should be removed using a three jawed puller. Technician B says that a harmonic balancer with a damaged keyway should be replaced. who is correct?
B only
Technician A says that a warpage of 0.300" (7.62mm) is acceptable for most pushrods. Technician B says that some pushrods are hallow in design to oil valvetrain components. Who is correct?
B only
Technician A says that positive valve stem seals must be installed before the valves are installed in the cylinder head. Technician B says that positive lip type valve stem seals must be pushed down firmly over the top of the valve guides. Who is correct?
B only
A cylinder is reading a 100 percent leakage during a cylinder leakage test. Technician A says the exhaust valve could be open. Technician B says the exhaust valve could be bent. Who is correct?
Both A and B
Compression test results are being discussed. Technician A says that if one cylinder is found to be low, a wet test should be performed to help narrow down the diagnoses. Technician B says that a difference of 10% between cylinders would be acceptable.
Both A and B
During a cylinder power balance test,one cylinder has very little rpm drop.Technician A says the ignition system may be misfiring on that cylinder. Technician B says the engine may have an intake manifold vacum leak. Who is correct?
Both A and B
Oil is leaking from the crankshaft rear main seal on an engine. Technician A says the oil seal could be faulty? Technician B says the PCV system may not be functioning. who is correct?
Both A and B
Technician A says a special puller and installer tool may be required to remove and install the vibration damper. Technician B says if the inertia ring on the vibration dampener is lose , the dampener must be replaced. Who is correct?
Both A and B
Technician A says improper valve timing may cause reduced engine power. Technician B says improper valve timing may cause bent valves. Who is correct?
Both A and B
Technician A says that a crankshaft must make two full rotations for the camshaft to make one. Technician B says that some engines vary the valve timing during operation to increase performance. Who is correct?
Both A and B
Technician A says that valve springs should be checked for squareness and pressure. Technician B says that seat pressure is measured with the spring compressed to the same height it would be when installed and the valve closed. Who is correct?
Both A and B
When discussing torque to yield bolts, Technician A says that compared to conventional head bolts torque to yield bolts provide a more uniform clamping force. Technician B says torque to yield bolts are tightened to a specific torque and then rotated tighter a certain number of degrees. Who is correct?
Both A and B
During a cylinder power balance test on a port fuel injected engine with coil on plug ignition, one cylinder is found to have virtually no rpm change. Which of these is the most likely cause?
Faulty fuel injector
All of the following are advantages of VVT systems except:
Increased emissions
A cylinder power balance test is being performed on an engine to determine which cylinder is causing a misfire. Technician A says that when the faulty cylinder is disabled, engine rp, will drop more than the other cylinders. Technician B says disabling the faulty cylinder will cause the engine to stall. who is correct?
Neither A nor B
An engine that demonstrated a single cylinder misfire is being diagnosed performing a leak down test. which of these is the most likely cause of the condition?
a faulty ignition wire
Which of these is the first thing to do when replacing a timing belt?
align the timing marks
All of the following can be accomplished with variable valve timing while the engine is running EXCEPT ____.
altering engine displacement
When installing a piston/ connecting rod into a cylinder block, which of the following steps is a technician LEAST LIKE:Y to perform?
check piston to cylinder wall clearance with plastigauge
Which of these would be the most common tool to use to measure crank end play?
dial indicator
An engine has had a major bearing failure. In addition to repairing the failed components, What other item should be replaced?
engine oil cooler
The vibration dampener rubber should be inspected for all of the following EXCEPT?
hub contact area scoring
During a cylinder leakage test, air is heard escaping from the intake manifold. Which of the following is the most likely cause?
intake valve
Which of these must be performed to measure valve lash on a mechanical valvetrain?
rotate the cam lobe to the base circle of the valve being adjusted
Crankshaft journals are measured for all of the following EXCEPT ____.
runout
Which tools would be used to check cylinder head warpage
straightedge and feeler gauge
The period of time that the exhaust and intake valves are both open is called:
valve overlap
