Mack E7 Service Manual page 281

5-101.bk Page 9 Friday, March 17, 2006 11:05 AM
Possible Cause
1. Oil level insufficient. Oil leaking from oil line,
gasket, etc.
2. Incorrect oil viscosity.
3. Defective oil pressure gauge.
4. Clogged oil filter(s).
5. Engine oil diluted with diesel fuel.
6. Defective oil pump relief valve.
7. Oil pump gears not meshing properly.
8. Excessive clearance between crankshaft and
bearings.
1. Defective oil cooler core.
2. Blown head gasket.
Cylinder sleeve seat seal failure.
1. Improper valve lash adjustment.
2. Blown head gasket.
3. Broken or weak valve springs.
4. Burned valves, seats or parts.
5. Piston rings stuck, worn, broken or improperly seated.
6. Camshaft or valve lifters worn.
200 TROUBLESHOOTING
LOW ENGINE OIL PRESSURE
1. Check engine oil level. Add oil if necessary. Check for oil leaks.
2. Drain oil, change oil filters, and fill with the proper grade oil
3. Check the operation of the oil pressure gauge. If defective, replace.
4. Replace oil filters. Clean or replace oil cooler. Drain oil and refill
5. Check fuel system for leaks. Make necessary repairs. Drain diluted
6. Remove oil pressure relief valve and check condition of seat.
7. Check mounting arrangement. If the engine has been rebuilt,
8. Overhaul the engine. Replace any worn/defective parts.
OIL IN THE COOLING SYSTEM
Possible Cause
COOLANT IN ENGINE OIL
Possible Cause
LOW COMPRESSION
Possible Cause
Correction
Repair as required.
meeting MACK specifications.
with oil meeting MACK specifications.
oil, change oil filters, and refill with oil meeting MACK specifications.
Check that relief valve spring is not sticking, and check for proper
spring tension. Check cap. Check assembly parts. Using the
incorrect parts will result in incorrect oil pressure. Make any
necessary repairs or install a new relief valve.
check that the gear ratio of the oil pump drive and driven gears are
correct. Incorrect gear combinations will result in immediate gear
failure and possible engine damage. Check for correct oil pad
gasket.
Correction
1. Disassemble and repair or replace oil cooler core.
2. Replace head gasket.
Correction
Repair cylinder sleeve seat seals.
Correction
1. Adjust valve lash to specified clearance.
2. Replace head gasket.
3. Check and replace defective parts.
4. Remove, recondition, and reinstall heads.
5. Overhaul engine.
6. Replace camshaft and/or valve lifters. Overhaul engine if
required.
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200782a
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