Engine Repair and Diagnosis Flashcards

How should a cylinder head deck surface be checked for warpage?

Answer: With a precision straightedge and feeler gauge lengthwise, crosswise, and diagonally

A straightedge and feeler gauge across several directions reveals flatness deviation against spec.

Which checks are performed on valve springs during a cylinder head rebuild?

Answer: Free length, squareness, and spring tension

Springs must meet free length, squareness, and open/closed pressure specifications.

The timing belt breaks on an interference engine while driving. What damage is most likely?

Answer: Bent valves from piston contact

In an interference design, valves open into the piston's path when cam timing is lost.

After refacing, a valve's margin is below the minimum specification. What should be done?

Answer: Replace the valve

A thin margin overheats and burns, so the valve must be replaced.

How should torque-to-yield cylinder head bolts be handled during a head gasket replacement?

Answer: Replace them with new bolts

TTY bolts are stretched into their yield zone on installation and will not clamp correctly if reused.

A VVT engine sets a crankshaft/camshaft position correlation code such as P0016 with a rattle at startup. What is a likely mechanical cause?

Answer: Stretched timing chain or worn tensioner/guides

Chain stretch shifts cam timing relative to the crank, triggering correlation codes.

After grinding a valve and its seat, valve stem installed height has increased. What is the effect and correction?

Answer: Spring pressure decreases; install a spring shim

A taller installed height lengthens the spring and reduces pressure, which shims restore.