Hey
i just bought a 85 Z-28 with $200km for 200 CDN it's in pretty good shape. the only problem is it burning oil when i start it and when i rev it.i did a compression test on but only the left side of the engine(no time)put they were all at 150 psi. i just wanted to know where u guys think the oil coming from.and if 4 cylinder were good does mean that the chances are the other 4 are good too?


thanks

 

Welcome aboard.

Most likely this is valve stem seal leakage. Very common in small block Chevys. The seals are o-rings under the valve keepers, they get hard and crack over time (especially when petroleum oil has been used).

They are relatively easy to replace, at least in the sense that it can be done with the engine in the car, and easier than rebuilding the engine. Realitively inexpensive, require a couple of special tools to do it (must compress the valve spring while holding the valve closed).

Most likely all 8 cylinders are okay, but can't really say without doing the compression check on the other 4.

 

ya i suspected it was the valves just want a second opinion
thanx

 

if anyone thinks its something else please let me know

 

well does it burn oil just on a startup, or all the time?

 

it burn oil at start up and when i rev it

 

at startup....and when you rev it? so otherwords....all the time....?

Check those other cylinders. I've seen it a few times where 7 out of 8 cylinders would have lovely compression, but 1 would have no ring at all left.