Hi there I have a 1986 z28 righthand drive manual camaro. The engine is carbed. Now when it warms up it starts to breath quite heavily and drips a little oil out the valve covers. It has breathers each side. I know its normal for them to breathe but when driving it the fumes come into the cabin. also when parked up at the lights it smokes out the bonnet and looks like it overheating. The motor burns no oil, it does puff a little black smoke on startup and with a good rev. The motor had good compression last time i checked. What do you think would cause this? and what can I do to help it? Can you block the breathers off abit? Many thanks Jared

 

You have your PCV valve hooked up?

 

Um no I dont. The pcv valve is the hose that runs from the top of the valve cover to the carb isn't it? I have aftermarket crome valve covers with a breather on each one. If i did hook the pcv valve up it would only stop one side breathing wouldnt it? or can you hook the other side into the aircleaner or does it even need a breather? Many thanks Jared

 

Thats it - the valve sits in the cover, and a hose connects it to the intake.

The carb/intake sucks crankcase gases/blowby out thru the pcv valve in one valve cover, which is replaced by fresh air coming in from the other valve cover. Filtered air either from the air cleaner or the little 'breather', whatever you've got.

If you have breathers in both covers and no PCV, there is no vacuum to remove the pressure in the crankcase and it'll puff like a steam train from wherever it can, especially if the rings are a bit past it. There is only one 'space' inside the engine - crankcase, valley, valve covers - it's all connected.

 

Awesome thanks very much for that i'll hook the pcv valve up this wknd and see what happens much appreciated Jared