(6) Oil pump screen choked.
(7) Oil pump drive inoperative.
(8) Oil lines choked, improperly tightened, or leaking.
b. High temperature.
(1) High cooling water temperature.
(2) Clogged oil cooler.
(3) Oil cooler bypass not operating.
Although locomotive trouble usually shows up in engine operation first, the trouble source often
is not in the engine. Troubles in the fuel system, air system, and electrical system affect all phases of
locomotive operation and cause the engine to run unevenly or not at all. Improper lubrication and
cooling are other common sources of trouble.
Whatever the defect, experience in repair work helps the repairman to locate it.