PLATE-TREAD 3326495 - Caterpillar

Introduction
The problem that is identified below does not have a known permanent solution. Until a permanent solution is known, use the solution that is identified below.Problem
Some of the 3408E engines and 3412E engines in the above listed machines may experience hard starting or low power due to oil that is leaking past the poppet valve in the injector. The oil leakage is caused by the operating conditions at either low idle or high idle. Excessive oil leakage can reduce actuation pressure to the fuel injector. This may prevent fuel injection.Solution
Electrical shock hazard. The electronic unit injector system uses 90-120 volts.
Follow the proper troubleshooting procedure for the correct engine. If the problem is not located and the symptoms that are listed above continue, remove the engine valve covers. Electrically disable the injectors. Crank the engine. Watch the spill ports of the injector for oil leakage. A small amount of oil leakage is acceptable. A continuous stream of oil may mean leakage from the poppet valve. Excessive leakage from the poppet valve may prevent fuel injection.Note: Normal oil pressure during cranking should be 5 MPa (725 psi). Oil pressure below 5 MPa (725 psi) may indicate excessive oil leakage in injectors. Do not replace the oil pump. Service personnel should replace the injectors that have a continuous flow of oil from the oil ports. Injectors that have a continuous flow of oil and injectors that are within the guidelines of warranty can be returned. Injectors that do not have a continuous flow of oil should not be replaced. Injectors that do not have a continuous flow of oil should not be returned.Note: For additional information on the operation of Hydraulic Electronic Unit Injectors HEUI, refer to CD, RENR1390.
Illustration 1 g01308874
(1) Oil drain portThe oil drain ports are located underneath the solenoid. This will direct the oil flow downward. Some oil may also leak from the rectangular slots at the side of the solenoid. Excess oil leakage will still be visible on the cylinder head.