Usage:
Fuel In Crankcase Oil
1. Defective Upper O-ring On Unit Injectors Or Leaking Unit Injector
Check for fuel on the top deck of the cylinder head. If fuel is found, drain the fuel supply manifold. Remove each unit injector (see 3176 Diesel Truck Engine Disassembly and Assembly, Form No. SENR3914), and check for a defective upper O-ring on the unit injector or if the unit injector itself is leaking.
Testing of the injectors must be done off of the engine. Use the 1U6661 Pop (Injector) Tester Group with a 1U6663 Injector Holding Block, and a 1U6665 Power Supply, to test the injectors. For the test procedure refer to Special Instruction, Form No. SEHS8867, Using The 1U6661 Pop (Injector) Tester. For test specifications refer to Special Instruction, Form No. SEHS8804, Unit Injector Test Specifications for 1.7 Liter Engines.
NOTE: Inspect and repair as necessary the sealing surface (seat) of the injector sleeve in the cylinder head when removing and installing an injector. The injector sealing surface (seat) must be free of scratches or evidence of combustion products. If it is necessary to rework (ream) or replace the sleeve use 4C4054 Tool Group and refer to Special Instruction, Form No. SEHS9120, Removal And Installation Of Unit Injector Sleeve.
2. Crack(s) In Cylinder Head
Pressurize the fuel gallery and check for crack(s). Crack(s) between the cylinder head fuel passages and passages open the crankcase will allow fuel to enter the crankcase.
3. Porosity In Cylinder Head
Pressurize the fuel gallery and check for porosity. Leakage may be due to the proximity of the hole to internal fuel passages.
4. Injector Not Seated Properly
Leakage at the upper O-ring due to a loose injector. Torque fuel injector hold down bolt to 30 ± 7 N·m (22 ± 5 lb ft).