ASE A1 Certification Practice Test

31.

Answer A is wrong. White carbon deposits around the electrode indicate a lean fuel condition.

Answer B is wrong. A Light tan or light gray colored spark plug tip is considered normal. Today’s fuel-injected engines usually turn the tip a light gray color. The center electrode should be square, not rounded because the spark readily jumps off a square edge.

Answer C is correct. A bad valve, valve seals, or worn piston rings result in oil burning in the combustion chamber and black carbon deposits on the spark plug tip.

Answer D is wrong. Black flakey soot on the tip and electrode indicates a rich fuel condition. If a spark plug is wet, it could be oil, fuel, or coolant. A dripping fuel injector will result in a wet spark plug tip that smells like raw fuel.

32.

Answer A is wrong. Worn valve springs result in valve float and a misfire at high engine speeds.

Answer B is wrong. The valve spring installed height is a measurement taken from the pocket or cup where the spring sits to the underside of the retainer/rotator with the valve closed.

Answer C is correct. A worn valve face or seat is the most likely cause. Measure the valve stem installed height with a valve stem height gauge.

Answer D is wrong. Loose cylinder head bolts result in a loss of compression, overheating, and white-colored exhaust.

33.

Answer A is wrong. Contaminated oil will clog the filter if the oil filter bypass valve is stuck closed. This will result in a swollen and ballooned oil filter.

Answer B is wrong. A stuck closed oil pressure relief valve would cause a ballooned oil filter.

Answer C is wrong. A stuck closed oil bypass valve would result in a ballooned oil filter. The oil filter oil bypass valve opens to prevent catastrophic oil starvation.

Answer D is correct. Each condition would result in a ballooned oil filter except for worn crankshaft bearings.

34.

Answer A is wrong. Use an outside micrometer to measure for camshaft journal wear.

Answer B is wrong. Use an outside micrometer to check for crankshaft journal wear. Check around and along the journals for taper or out-of-round.

Answer C is correct. Measure crankshaft end play with the dial indicator's tip on the crankshaft flange. Use a pry bar or a large screwdriver to move the crankshaft back and forth.

Answer D is wrong. Answer C is correct. If there's a sharp rapping noise, especially at idle, the crankshaft should be inspected and measured for crankshaft endplay.

35.

Answer A is wrong. Liquid-cooled intercoolers contain piping, a coolant reservoir, and a radiator.

Answer B is wrong. The intercooler's radiator, usually located at the front of the vehicle where fresh air can pass through, releases heat to the atmosphere.

Answer C is correct. The intercooler's job is to cool the compressed, heated air charge before entering the combustion chamber. This cooled charge increases the engine's horsepower and prevents harmful detonation.

Answer D is wrong. Liquid-cooled intercoolers typically require a 50/50 mixture of antifreeze to water. They are leak tested similar to the engine's cooling system.