This morning i started the old coupe ('66 289V8) and let her run for a while. After a while (when i turned her off) i saw smoke coming from the dipsticktub and underneath the manifold. I carefully checked the radiotor fluid but that was ok. I noticed some oil on the back of the manifold, where the engine connects to the gear box.


Is it overheating ? What can this be ?

PS: Thermostat was already replaced a few months ago.

Have you checked the oil level to see if its too low? If smoke and oil is coming out from underneath the manifold then you may not have it sealed right. The oil will smoke if it sits on the hot engine obviouslly so if its leaking out that could be one reason for it.

I was afraid you might say this. Yes the oil level was less than usual. And the oil was on the rear of the manifold. So it must be the gasket. Damned thats a lot of work ... again. I just replaced it last year. I did everything the way it should, used the cork thingies in front and rear.

Should i lose the corks and replace them with a thick layer of RVT kit ?

yeah, dump the cork. Also , how old is your pcv valve? May be time for a new one.

Its only a year old. So i dont need to replace that PCV valve.

So your adivise is to use only heat resistantsealer. Wish i would have know this a year ago. Would have saved me a lot of time.

That's a tough area to seal. The corks work, but you have to be carefull when you drop the manifold back on. Some have suggested cutting off the top of a couple of bolts so you have guide pins to put the manifold down. Use theRTV in combination with rubber end seals. Put a liberal amount in the corners where the side and end gaskets come together. good luck.

where do i get rubber end seals ? Because the cork ones come with the intake gaskets.
And what will be the difference with cork ones ?

Before taking off the intake manifold again, I'd check to make sure that the hose from the PVC valve isn't oily. I had an old Pontiac with worn compression rings that used to blow a bit of oil out the PVC valve and made a mess in the air cleaner.

I'm not sure having a bit of vapour coming out of the dipstick or filler cap on a hot engine is too unusual. My 66 Coupe and 94 F150 both do that a bit.

Thanks but the oil is definitely coming out of the back of the manifold. The PCV valve is clean.