Hi there. My wife has a 1996 Civic sedan 1.6L, which had the typical air bubbles in the coolant issue, a headgasket. I replaced the headgasket and no more bubbles, great. Runs great., however....

...for some reason, there is a lot of blowby at idle. When revved up the blowby reduces significantly. The blowby is clear, with an oil mist smell to it. It's the smell that bugs the wife, as the hvac intake is sucking this mixture in. I seem to not be burning oil.

Has anyone experienced this before?

I realize my next steps are a compression and leakdown test...wondering if somehow an improvement in compression may have translated into increased blowby on the rings??

Thanks,

Chay

 

Dumb question: why would you be smelling blowby? any blowby should end up back in the intake via the pcv system.

 

My dad told me a while ago that putting in a new head gasket often reveals piston ring problems that were hidden before (since you're fixing lost compression). He's not a mechanic though so take that with a grain of salt.

 

Bad head gasket causes overheating, continuing to drive while overheated is likely to damage the rings.

 

No overheat issues. There is so much blowby it can't be relieved via the small hose when at idle. When driving its no problem because the blowby is lower and there is vaccum on the line and also there is fresh air hitting the heater air intake. The smell is only at idle when all the conditions are right

i guess the rings could seat as the cylinder is loaded up. Cant think of another reason why the blowby would go down with increased throttle. Weird!!!!

chay