White Smoke & Oil from Breather Cap

[Anonymous]

We have a 78 200 in my son's 66 Mustang. He started using water internally with white smoke coming out from the breather cap and from the exhaust. Tuesday night we changed his head out to a rebuilt 67 head that I had. Water is holding fine. Did see that we had an oil leak on the previous head gasket, so I'm thinking that either the head was warped, or gasket was bad.

At any rate, everything is operating fine , except that he is blowing oil out of the breather. We're using the 78 valve cover with the breather in the back. Also getting smoke from the breather cap when we rev the engine. PCV valve seems fine. I'm stumped. Is a new breather cap, though it does not seem to seal that well against the valve cover. Help! As I stated, the water is doing fine. No sign of using any, and no sign of water in the oil. Also, no smoke from the exhaust. Exhaust fumes smell normal and is clear. I need suggestions.

 

[CobraSix]

This is while the engine is running I take it.

Stupid question, not clear in the description. Is if spitting oil and smoke with the cap on or off? If it is doing it with the cap off, that's pretty normal. If it is doing while on, I would consider a new valve cover, or put a rubber o-ring in the breather.

Slade

 

[MustangSix]

The PCV should be pulling a very strong vacuum at idle. Check the passage where the PCV hooks to the carb base. Sometimes this gets clogged and you don't get proper vacuum . Also ensure the hose is not collapsing.

 

[addo]

It's likely just blow-by from bore wear. Did you notice any lipping of the cylinder tops with the head off? Or any scoring? Try a compression test, and post some results. Warm the motor first until the thermostat opens, pull all the plugs (noting each appearance) and test compression. Then squirt a table spoon of oil into each cylinder immediately before retesting its compression. Again note the results. Then we'll know where you're heading.

Regards, Adam.