TM 5-3895-383-24
Problem 17: Too Much Valve Lash
Probable Cause(s):
End Of Stem Worn Or Rocker Arm Contact
Surface Worn
Worn Push Rods
Broken Or Worn Valve Lifter
Worn Lobes On Camshaft
Not Enough Lubrication
1.
End of valve stem worn or rocker arm contact surface
worn:
If there is too much wear, install new valves or
rocker
arms.
Check
and
make
necessary
adjustments as per Testing and Adjusting Section
of the Service Manual.
2.
Worn push rods:
If there is too much wear, install new valves or
rocker
arms.
Check
and
make
necessary
adjustments as per Testing and Adjusting Section
of the Service Manual.
3.
Broken or worn valve lifter:
Install new valve lifers. Check camshaft for wear.
Check for free movement of valves or bent valve
stem. Clean engine thoroughly. Check and make
necessary
adjustments
as
per
Testing
and
Adjusting Section of the Service Manual.
4.
Worn lobes on camshaft:
Check valve lash. Check for free movement of
valves or bent valve stems. Install a new camshaft.
Install new valve lifters. Check and make
necessary
adjustments
as
per
Testing
and
Adjusting Section of the Service Manual.
5.
Not enough lubrication:
Check lubrication in alve compartment. There
must be a strong flow of oil at high engine rpm, but
only a small flow at low rpm. Oil passages must be
clean, especially those sending oil to the cylinder
head.
Problem 18: Little Or No Valve Lash
Probable Cause(s):
Worn Valve Seat Or Face Of Valve
1.
Worn valve seat or face of valve:
Reconditioning of cylinder head is needed. Check
and make necessary adjustments as per Testing
and Adjusting Section of the Service Manual.
Problem 19: Oil At The Exhaust
Probable Cause(s):
Failed Turbocharger Seals
Worn Or Failed Valve Guide Seals
Worn Valve Guides
Broken Or Worn Piston Rings
Scored Or Worn Cylinder Wall(s)
1.
Failed turbocharger seats:
Check inlet manifold and exhaust manifold for oil. If
oil is present, repair the turbocharger.
2.
Worn or failed valve guide seals:
Inspect seals and replace as necessary.
3.
Worn valve guides:
See the Specifications Section of the Service
Manual for the maximum permissible wear of the
valve guides. If necessary, recondition the cylinder
head.
4.
Broken or worn piston rings:
Pistons or rings that have damage can be the
cause of too much pressure in the crankcase. This
condition will cause more than the normal amount
of fumes (blow-by) coming from the crankcase
breather. The 8T2700 Indicator Group is used to
check the amount of blow-by. The test procedure is
in Special Instruction, SEHS8712. Inspect and
install new parts as needed.
5.
Scored or worn cylinder walls:
Inspect cylinder walls for problems. Hone, or bore
and sleeve as necessary.
Problem 20: Engine Has Excessive Early Wear
Probable Cause(s):
Dirt In Lubrication Oil
Dirt In The Inlet Air
Fuel Leakage Into Lubrication Oil
Incorrect Lubrication Oil
Incorrect Engine Settings
1.
Dirt in lubrication oil:
Remove dirty lubrication oil. Install new filters. Put
clean oil in the engine. Check oil filter bypass valve
for a weak or broken spring.
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