TM 5-3805-280-24-2
Cylinder Head and Valves
PRELIMINARY CYLINDER HEAD AND VALVE CHECKS
05
26
Distorted cylinder head.
Make preliminary inspection of cylinder head and valve
Carbon deposits on seats due to incomplete
assembly during disassembly.
Valve spring tension too weak.
Look for the following conditions:
Excessive heat.
Improper valve clearance.
Sticking Valves:
Improper valve timing.
Incorrect valve or seat installed.
Carbon deposits on valve stem.
Worn valve guides.
Burned, Pitted, Worn, or Broken Valves:
Scored valve stems.
Warped valve stems.
Worn or distorted valve seats.
Misaligned or broken valve springs.
Loose valve seats.
Worn or distorted valve seats.
Worn valve guides.
Insufficient lubrication.
Insufficient cooling.
Cocked or broken valve springs.
Warped, Worn, or Distorted Valve Guides:
Improper engine operation.
Improper valve train timing.
Lack of lubrication.
Faulty valve rotators.
Cylinder head distortion.
Warped or distorted valve stems.
Excessive heat.
"Stretched" valves due to excessive spring tension.
Unevenly tightened cylinder head cap screws.
Warped cylinder head.
Bent push rods.
Distorted Cylinder Head and Gasket Leakage:
Carbon build-up on valve seats.
Rocker arm failure.
Loss of cylinder head cap screw torque.
Incorrect valve or seat installed.
Broken cylinder head cap screw.
Incorrect piston-to-valve clearance.
Overheating from low coolant level operation.
Insufficient liner standout.
Improper Valve Clearance:
Coolant leakage into cylinder causing hydraulic
failure of gasket.
Inefficient use of fuel.
Leaking aftercooler.
Engine starts harder.
Cracked cylinder head.
Maximum engine power will not be achieved.
Cracked cylinder liner.
Shorter service life of valve train.
Damaged or incorrect gasket.
Greater chance for engine to overheat.
Overpowering or overfueling.
Damaged cylinder head or block surfaces.
Excessive Recession:
Improper surface finish on cylinder head.
Improperly tightened cylinder head cap screws.
Worn valve guides.
Faulty gasket installation (misaligned).
Bent valves.
Debris passed through valve train.
Worn or Broken Valve Seats:
Misaligned valves.
RG,05,DT7367 1911NOV971/1
13-84
