Internal Oil Leak in a Honda Civic

A Honda Civic internal oil leak leads to cross-contamination. Cross-contamination is when the oil and antifreeze coolant mix inside the engine. This limits the oil's ability to lubricate engine parts and leads to engine failure.

Verify Cross-Contamination

Open the radiator cap when the engine is cold to avoid burning yourself. Look inside the radiator and inspect the coolant. There will be settled oil at the top of the radiator floating on top of the coolant if there is cross-contamination.

Engine Block

Check to see how deep the cross contamination goes by checking inside the engine block. Crawl underneath the vehicle and use a socket wrench to unfasten the drain plug on the oil pan, drain the oil into an automotive fluid pan and check the color of the oil. If the oil looks like a chocolate milkshake, the cross-contamination is deep in the engine block.

Head Gasket

Deep inside the engine, separating the engine block and the cylinder heads, is the head gasket. If the head gasket breaks, cross-contamination will occur and the gasket must be replaced. It is a time-consuming and expensive repair that must be done to avoid catastrophic engine damage.

References

• "Honda Civic 1996-2000 Service Manual"; Honda Motor Co., LTD Service Publication Office; 1999
• "Chilton's Honda Civic, CRX and Del Sol 1984-95 Repair Manual"; Jaffer A. Ahmad; 1995