Procedure
1. Check oil level to verify oil contamination complaint.
• The presence of coolant in the oil will generally give the oil a dark-gray or black sludgy appearance.
• If coolant in the oil is not verified, an oil sample can be taken for analysis.
2. When oil contamination is verified, plug in cylinder block heater to warm coolant.
3. Is the engine equipped with an air compressor?
• If yes, do step 4.
• If no, do step 8.
4. Remove air compressor oil drain-back hose from the bottom of compressor.
5. Install radiator pressure tester with the appropriate adapter.
6. Pressurize the cooling system to 96 kPa (14 psi).
7. Look for coolant leaking from the air compressor oil drain-back port.
• If coolant is leaking from air compressor, repair or replace air compressor.
• If coolant is not leaking from the air compressor oil drain-back port, do step 8.
8. Drain engine oil and remove the oil filter.
9.Remove the oil pan following the procedure in the Engine Service Manual.
10. Install radiator pressure tester with the appropriate adapter.
11. Pressurize cooling system to 96 kPa (14 psi). Look for coolant leaks.
• If the engine is equipped with an air compressor, and is leaking from the compressor oil drain-back hose or from the left side of the front cover, do “Air Compressor Leak Test.”
• If the engine does not have an air compressor, and is leaking from the front cover area or the oil pick-up tube, do “Front Cover Inspection” (page 111).
• If a leak is noticed between the cylinder sleeve and piston, replace the injector sleeve for that cylinder. Follow the procedure in the Engine Service Manual.
• If a leak is noticed between the cylinder sleeve and the engine block, replace the cylinder sleeve crevice seal for that cylinder. Follow the procedure in the Engine Service Manual.
• If a leak is noticed from the oil drain-back ports (camshaft side), do “Cylinder Head Leak Test” (page 112).
• If no leak is noticed, leave pressure on cooling system overnight and check the following day.
• If no leak is noticed after overnight pressure test, do the following sequential tests until problem is found:
A. “Front Cover Inspection” (page 111)
B. “Cylinder Head Leak Test” (page 112)
12. After any repairs are complete, test the cooling system again to validate the repair.
