PowerTech 6105HF - Preliminary Cylinder Head and Valve Checks

Cylinder Head and Valves
02
020
22
RG,RG34710,72 –19–30SEP97–1/1
Preliminary Cylinder Head and Valve Checks
Make preliminary inspection of cylinder head and valve
assembly during disassembly.
Look for the following conditions:
Sticking Valves:
• Carbon deposits on valve stem.
• Worn valve guides.
• Scored valve stems.
• Warped valve stems.
• Misaligned or broken valve springs.
• Worn or distorted valve seats.
• Insufficient lubrication.
Warped, Worn, or Distorted Valve Guides:
• Lack of lubrication.
• Cylinder head distortion.
• Excessive heat.
• Unevenly tightened cylinder head cap screws.
Distorted Cylinder Head and Gasket Leakage:
• Loss of cylinder head cap screw torque.
• Broken cylinder head cap screw.
• Overheating from low coolant level operation.
• Insufficient liner standout.
• Coolant leakage into cylinder causing hydraulic
failure of gasket.
• Leaking aftercooler.
• Cracked cylinder head.
• Cracked cylinder liner.
• Damaged or incorrect gasket.
• Overpowering or overfueling.
• Damaged cylinder head or block surfaces.
• Improper surface finish on cylinder head.
• Improperly tightened cylinder head cap screws or
faulty gasket installation (misaligned).
Worn or Broken Valve Seats:
• Misaligned valves.
• Distorted cylinder head.
• Carbon deposits on seats due to incomplete
combustion.
• Valve spring tension too weak.
• Excessive heat.
• Improper valve clearance.
• Improper valve timing.
• Incorrect valve or seat installed.
Burned, Pitted, Worn, or Broken Valves:
• Worn or distorted valve seats.
• Loose valve seats.
• Worn valve guides.
• Insufficient cooling.
• Cocked or broken valve springs.
• Improper engine operation.
• Improper valve train timing.
• Faulty valve rotators.
• Warped or distorted valve stems.
• “Stretched” valves due to excessive spring tension.
• Warped cylinder head.
• Carbon build-up on valve seats.
• Rocker arm failure.
• Incorrect valve or seat installed.
• Incorrect piston-to-valve clearance.
Improper Valve Clearance:
• Inefficient use of fuel.
• Engine starts harder.
• Maximum engine power will not be achieved.
• Shorter service life of valve train.
• Greater chance for engine to overheat.
Excessive Valve Recession:
• Worn valve seats.
• Bent valves.
• Debris passed through valve train.
CTM100 (06APR04) 02-020-22 P OWER T ECH 10.5 L & 12.5 L Diesel Engines
040604
PN=94