TM 5-3805-291-23-1
ENGINE TESTS, INSPECTIONS, AND ADJUSTMENTS - CONTINUED
0010 00
ENGINE OIL PRESSURE TEST - CONTINUED
Reason for High Pressure Oil Pressure
Engine oil pressure will be high if the engine oil bypass valves become stuck in the closed position and the engine oil
flow is restricted. Foreign matter in the engine oil system could be the cause for the restriction of the oil flow and the move-
ment of the engine oil bypass valves. If the engine oil bypass valves are stuck in the closed position, replace engine oil filter
base (WP 0028 00) in order to correct this problem. Install new engine oil filters (WP 0025 00). New engine oil filters will pre-
vent more debris from causing this problem.
0010 00
EXCESSIVE ENGINE OIL CONSUMPTION
Engine Oil Leaks on the Outside of the Engine
1.
Check for leakage at the seals at each end of the crankshaft and replace main seal if leaking (WP 0174 00 and WP 0175
00).
2.
Look for leakage at the gasket for the engine oil pan and all lubrication system connections. Replace oil pan gasket if
leaking (WP 0181 00).
3.
Look for any engine oil that may be leaking from the crankcase breather. This can be caused by combustion gas leakage
around the pistons. A dirty crankcase breather will cause high pressure in the crankcase. A dirty crankcase breather will
cause the gaskets and the seals to leak. Replace or clean crankcase breather as necessary (WP 0026 00).
Engine Oil Leaks into Combustion Area of the Cylinders
N OT E
Engine oil that is leaking into the combustion area of the cylinders can be the cause of blue smoke. There
are several possible ways for engine oil to leak into the combustion area of the cylinders.
1.
Remove valve cover (WP 0024 00) and look for leaks between worn valve guides and valve stems.
2.
Remove oil pan (WP 0181 00) and look for worn components or damaged components (pistons, piston rings, or dirty
return holes for the engine oil).
3.
Look for incorrect installation of the compression ring and/or the intermediate ring. If suspected, replace engine (WP
0171 00).
4.
Look for leaks past the seal rings in the turbocharger shaft (WP 0032 00).
5.
Check for overfilling of the crankcase (TM 5-3805-291-10).
6.
Ask operator if there has been sustained operation at light loads.
7.
Excessive consumption of engine oil can also result if engine oil with the wrong viscosity is used. Engine oil with a thin
viscosity can be caused by fuel leakage into the crankcase or by increased engine temperature. Change engine oil (WP
0025 00) and use correct oil for the climate.
END OF WORK PACKAGE
0010 00-6
