KW1985Z28

Hey guys,

I'm new to the forum and this is my first post... Hoping I'm in the right spot. Anyways, onto the issue, I have a 1985 Z28 that has sat for far too long. (2+ years) I recently wanted to start restoring it and driving it, but it has some mechanical issues. First off, it smokes lightly when idling from the exhaust (bluish smoke I'm assuming is oil) which I knew when I parked it. It will puff a cloud of smoke under acceleration and again appears to be bluish and lingers for a minute. Recently though, when I started it and let it idle it began to smoke from the engine bay. However, this appears to be white smoke and I couldn't smell antifreeze or oil in it. It gets worse as it idles. I am assuming it is one of two things, the piston rings are totally shot or the head gasket has failed. Here is my main dilemma, if it is a gasket issue I wouldn't mind buying a kit and replacing all gaskets, however if it is piston rings I am going to hold off and do my engine swap to a 350 TPI. (Considering lsx engine)

I know it is not possible to diagnose over the web, but want some opinions. Also, what are your opinions on compression testing it and performing a leak down test? I see a lot of people go back and forth. Thanks guys, I have researched for days but always end up feeling like other posts only cover half my issue. Again, I'm new to this forum stuff.

TylerSteez

iTrader: (3)

First guess for the bluish smoke out the exhaust is valve guide seals. For the white smoke, try and see exactly where it's coming from, I had a cracked exhaust at the y pipe which made it seem like smoke from the engine bay.

Definitely test the compression and do the leak down test to see how your rings are holding up.

KW1985Z28

Thanks for the reply. So if the leak down has the air escaping due to bad rings, where will I hear it? At TDC will the valves be open or closed, if closed then I guess that would help determine if it was valve stem seals right? Sorry... I love working on cars, but I have never tried a leak down test.

Jonesyfxr

iTrader: (2)

If it sat that long it could be a leaking valve cover. My car sat for 2 years and does the same thing. It looks white but was oil.

TylerSteez

iTrader: (3)

leak down test-
https://www.thirdgen.org/forums/tech...leak-down.html

https://www.thirdgen.org/forums/tech...leak-down.html

KW1985Z28

It's sounding like I'll just tackle both tests. If I'm replacing the engine anyway, might as well look into this one. I'll get into the heads and look at all seals as well as the valve cover seals. Maybe it's still salvageable, at least that's what I'm hoping for. If the valve stem seals and valve cover seals look shot, then that's probably my issue. Worst case, I guess I'm out 80 bucks and some labor time.

TylerSteez

iTrader: (3)

not sure if you're replying to my post or not but I got your question confused so I edited my post with the correct information from other threads. sorry about that

KW1985Z28

Sorry Tyler, I did kind of a blanket reply. Thanks for the help man. Can't wait to be driving this beautiful car again.