99' Civic 1.5l Oil mixing with coolant problem.

KI55

MEMBER
1999 HONDA CIVIC

First off, the car also has a jackson supercharger but I don't think this would cause the problem. The oil is showing up in the cooling system including the overflow. Coolant is think and black with oil. Car also goes through aproxx 2 quarts of oil per gas fill-up. But it doesn't seem to be burning it out the exhaust. Naturally I thought it was a head gasket so I replaced that and had the system flushed. Problem still exists. I visually checked for head cracks the best that I could and didn't see any. My first question is; are there any other spots where the coolant and oil could meet other than head/block? I am not to familiar with hondas aluminum block/head and the piston sleeve system. Also the owner told me the car never overheated (take that with a grain of salt). Do the aluminum engine blocks ever crack? Any ideas would be great, thanks in advance!

1 Reply

BRUCE HUNT

MECHANIC
3,753 POSTS

I doubt your eyes are much better than mine, especially when I have my reading glasses handy. I know I can look at a block or head and possibly detect a crack, but there are fine cracks that go unobserved without additional help. Experts coat the head with a solution that can bring these light. I know that an warpage to the head would also go unnoticed to most naked eyes.

Let me be blunt, if you put the dollars in to attempting to super charge an engine, put another $60 in to having the head planed and checked. You never said what the old head gasket looked like. A warpage doesn't car whether the head gasket looks fine. The head isn't touching the head gasket 100% and won't until it is replaced or planed.

I would however, consider the definate possibility that the block is cracked. You say that the oil is in the coolant, but I would venture that the coolant is also in the oil.