1980 camaro. Chev 350 rebuilt approx 30K miles ago (8 years ago)


I have a weird issue of some grey smoke comming out the exhaust...

When I first start it I get the classic small puff of smoke, and then all is well. It has been doing this for a couple of years...

I can rev it up for about the first 5 mins it runs and not a sign of any smoke. But as soon as it warms up there is quite a bit of grey smoke comming out both mufflers upon both accelleration, and again when I let off the throttle. I have confirmed it is NOT coolant.

I initially thought it was my PVC so I replaced it. It did nothing.

When I pull out the PVC a slight amount of Smoke does come out the hole in the valve cover. WHen I plug the hole with my finger, a small amount of smoke comes out the breather. WHen I give it gas it does get worse.

Once again it ONLY smokes after it is warmed up. Not even a trace of smoke for the 1st 5 mins it is running.

Any ideas??? Do you think it is carb related. Carb is the original Q-Jet.

does anyone think it could be carbon buildup? I called a good buddy who thought that is what it could be. It can only burn off after the engine is hot.

ANy idears..

I don't think it is carbon smoke as it would be black. Grey or blue smoke would be oil. Since it is coming out the breather and pcv, I would say it is ring blow-by. Does the pcv valve have good vacuum when you pull it out the valve cover? If not, the hose or vac port is plugged and should be cleared. You may also have oil seeping thru the valve guides.

I thought it couldn be blow by, but wouldn't it also smoke as it was warming up with blowby. In addition, the plugs look fine normal with no signs of oil usage.

To clarify, it only smokes out the breather if I plug the PVC port on the valve cover with my finger.

It is weird, there is 0% smoke for about 5 mins (even if you are hard on it) and then all of the sudden here is smoke. THe smokeis NOT blue at all, only grey...

There is lots of vacumn at the PVC and seems to work 100%.

Is the choke opening completely? Also, after the engine warms up and starts smoking, pull the plugs and see if one or more is fouled. If so, then start there and look at ignition wires, cap and the plug itself. Maybe do a compression test when the engine is warm. Pull all the plugs when you do this to make it easier on your starter and battery. Possibly a cracked head???? Just throwing out idears.

Yes I know a compression test should tell me with some better direction.

I know my valve seals and guides are bad. I have had the puff at startup for a long time, and it has always gotten worse.

I just thought it was odd that I only get the smoke after my motor is warmed up.

The electric choke on my Q-Jet is brand new.