ENGINE REPAIR MICHIGAN MECHANIC COMPLETE EXAM 2025

Which of the following is true about adjusting valve tappet clearance - - A. The valve tappet clearance on a high mileage engine should be adjusted tighter than specifications for a newly rebuilt engine. B. Valve tappet clearance should be adjusted at tdc at the end of the compression stroke. (correct answer) C. Valve tappet clearance should be adjusted at bdc at the end of the exhaust stroke. D. None of the above. (not correct answer) The hydraulic lifters are noisy at highway speeds but quiet at low speeds. What should you do first as you diagnose this problem? - -a. Check lifter leakdown rate. B. Check crankcase oil level. (correct answer) C. Check lifter clearance hot. (not correct answer) D. Check lifter clearance cold. The valve timing on most engines is controlled by: - -a. An on board computer. (not correct answer) B. A centrifugal advance unit. C. A vacuum advance unit D. A belt, chain or gear drive. (correct answer) The bearing inserts below have been plastigaged. What can you determine about these pictures? - -a. Both bearing journals are out of round. (not correct answer) B. Insert "b" has more clearance. C. Insert"a" has more clearance. D. Both bearings have excessive taper. The compression test has showed that the middle two cylinders on one side of a v-8 engine had readings of 50 psi. The other cylinders had readings between 135 psi and 140 psi. What is the likely cause of this condition? - -a. A burned exhaust valve B. A blown intake manifold gasket. C. A blown head gasket. (correct answer) D. A burned intake valve. (not correct answer) Excessively worn valve guides: - -a. May be replaced if removable. B. May be reamed to oversize. C. May cause oil consumption. D. All of the above. (correct answer) MLT 106 MLT 106 Intake valve deposits, as shown below: - -a. Will not affect engine performance. B. Can reduce volumetric efficiency and affect high rpm performance. C. Can cause driveability problems during cold engine operation. D. Both b and c. (correct answer) What is being checked on the valve spring in the illustration below? - -a. Installed height (correct answer) B. Squareness C. Coil taper D. Tension (not correct answer) You are using a vacuum gauge connected to the intake manifold. Which of the following is true? - -a. When the engine is rapidly accelerated, the needle will rise to a high reading. (possible correct answer) B. When the throtle is released suddenly from 2500 rpm, the needle will snap to a higher than normal reading for an instant. C. A "normal" gauge reading at idle would be 7-10 inches. D. All of the above. (not correct answer) What are the minimum and maximum measurements of a shaft given 2.125 plus or minius .015? - -a. 2.062-2.250 (not correct answer) B. 1.975-2.275 C. 2.110-2.140 (correct answer) D. 2.124-2.126 The mechanic has determined that no fuel squirts into the carburetor when the throttle is opened quickly. What could be caused by: - -a. Disconnected linkage. B. A hardened accelerator pump plunger. C. A plugged pump nozzle. D. All of the above. (correct answer) A warm engine has low oil pressure. The most likely cause of the low oil pressure is: - a. Leaky main bearing seals. (correct answer) B. Worn valve guides. C. Worn bearings. D. Leaky hydraulic lifters (not correct answer) What is the reading of the 0-1 inch micrometer below? - -a. 0.575" (not correct answer) B. 0.599" C. 5.750" (correct answer) D. 1.599" You are reinstalling pistons with new rings. The ring compressor will not fit tight around a piston skirt and the rings bind on the block surface. What should you do? - -a. Check the ring end gap. (correct answer) MLT 106 MLT 106 B. File the lands. C. Use a ridge reamer. D. Honen the cylinder for more clearance. (not correct answer) You have checked the crankshaft and found thye following measurements below. The rod journal surfaces are smooth and no rod journal taper is present. What should you do? (use given specifications and measurements.) - -a. Intall 0.010" undersize bearings in all rods. B. Install 0.005" undersize bearings in all rods. C. Grind the crank because of too much rod journal out-of-round. D. Install standard bearings in all rods. (correct answer) You have measured the cylinders and obtained the measurements given below. All the cylinders are smooth and the pistons are reuseable. What should the mechanic do? - a. Have the block honed oversize and use oversize pintons. B. Have the block bored 0.010" oversize. There is too much out-of-round. (not correct answer) C. Have the block bored 0.010" oversize. There is too much taper. D. Deglaze cylinders, use original pistons and new standard rings. (Correct answer) Refer to the manufacturer's specifications in the image. You could find the amount of bore taper by: - -a. Adding measurement "c" and "d" together. B. Subtracting measurement "d" from measurement "c". C. Subtracting measurement "a" from measurement "b". D. Adding measurement "a" and "b" together. (not correct answer) Valve-tappet clearance on a running engine with hydraulic lifters is: - -a. .012" to .014". B. .006" to .008". (possible correct answer) C. Zero D. .014" to .016". (not correct answer) What is the purpose of valve-tappet clearance? - -a. To allow for proper lubrication of the valve. B. To compensate for temperature change and valve train wear. (correct answer) C. To prevent valve guide wear. D. To adjust for valve timing. With the radiator cap removed and the engine warmed up and running, you can see bubbles in the coolant. What would likely cause this to happen? - -a. Too much glcol in the coolant solution, causing a high boiling point. B. The thermostat is set to open at too low a temperature. (not correct answer) C. The coolant is boiling due to a combustion chamber hot spots. D. The head gasket is leaking. (correct answer) MLT 106 MLT 106 You have finished grinding an exhaust valve. What should the margin be? - -a. About 1/16 inch. (not correct answer) B. About 3/16". C. As narrow as possible. D. .001"-.003". (possible correct answer)