Table 4-1.--Diesel Engine Troubleshooting Chart--Continued
TROUBLE
PROBABLE CAUSE
REMEDY
Abnormal oil pressure:
High oil pressure.
Oil viscosity wrong.
Change oil to specified grade.
Oil filter clogged.
Change oil filter element.
Engine temperature below normal.
Refer to Abnormal Coolant
Temperature.
Coolant in oil.
Faulty head gasket.
Replace engine. (Refer to QEC in-
structions.)
Faulty oil cooler.
Replace damaged parts.
Faulty water pump seal.
Replace damaged parts.
Cracked, damaged, or warped cyl- Replace engine. (Refer to QEC in-
inder liner, cylinder head, or engine struction.)
block.
Low oil pressure.
Low oil supply.
Fill sump to dipstick full mark.
Air leak in oil pump suction line.
Tighten oil line fittings.
Check oil lines for breaks. Replace
defective parts.
Oil viscosity low.
Drain system, use oil of specified
weight.
Check oil for dilution by fuel or
water. Replace defective parts.
Oil pressure gauge or sending unit Replace pressure indicating defec-
defective.
tive parts.
Oil pressure regulator sticking in Clean or replace defective parts.
open position.
Oil pump screen clogged.
Clean or replace defective part.
Oil pump defective.
Replace engine. (Refer to QEC in-
structions.)
Correct oil pump flange leak.
Oil cooler bypass valve stuck closed. Clean or replace parts.
4-46
