DETROIT DIESEL 53
1. Check for carbon deposits, a bent valve guide, defective spring or antifreeze (glycol) in the lubricating oil.
Replace a bent guide. Clean-up and reface the valve. Replace the valve if necessary.
2. Check for excessive valve-to-guide clearance, bent valve guide or carbon deposits. Replace a bent or worn guide.
Clean the carbon from the valve. Reface or replace the valve, if necessary.
3. Check the operating conditions of the engine for overload, inadequate cooling or-- improper timing. Reface the valve
and insert. Replace the valve if it is warped or too badly pitted. Use a harder-face valve if operating conditions warrant.
4. Check for contact between the valve head and the piston as a result of incorrect valve clearance, an improperly
positioned exhaust valve bridge (four valve head) or a defective spring. Check the valve guide, insert, cylinder head and
piston for damage. Replace damaged parts.
5. Check for excessive valve-to-guide clearance, defective valve spring or etching of the valve stem at the weld.
Improper valve clearance is also a cause of this type of failure. Check the guide, insert, cylinder head and piston for
damage. Replace damaged parts.
6. Replace a worn valve guide. Check and replace the valve, if necessary.
7. Black carbon deposits extending from the valve seats to the guides indicates cold operation due to light loads or to
the use of too light a fuel. Rusty brown valve heads with carbon deposits forming narrow collars near the guides indicate
hot operation due to overloads, inadequate cooling or improper timing which results in carbonization of the lubricating oil.
Clean-up the valves, guides and inserts. Reface the valves and inserts or replace them if they are warped, pitted or
8. Check for a worn valve guide or excessive exhaust back pressure. Replace a worn guide. Check the valve seat for
improper seating. Reface the valve and insert or, if necessary, replace.
9. Check for a bent valve stemor guide, metal chips or dirt, or for lack of lubrication. Clean up the valve stem with
crocus cloth wet-with fuel oil or replace the valve. Replace the guide. When installing a valve, use care in depressing
the spring so that the spring cap DOES NOT scrape the valve stem.
10. Check for a gear train failure or for improper gear train timing.
II. Check the operation of the engine for excessive idling and resultant low engine exhaust back pressure. Install valve
guide oil seals.