I think I've narrowed down the problem with my motor to bad valve seals. It smokes sometimes during start up and if I rev it when after starting the motor while it's been sitting for a long time. After I drive it for a while, I can sit there and rev it and it doesn't burn oil. When I come up to stop lights I can smell a little bit of oil burning but don't really see much. Also when I'm in boost it will burn some white smoke (according to what my friends tell me)... but I've never seen a boosted car not burn something in boost lol. Under normal driving conditions it's fine though.

Compression numbers were 150-160-165-180.

Motor burns about 1 quart every 1500 miles.

I really need to get hold of a leak down tester but I'm working with what I have.

Any ideas? Would valve seals cause that much oil loss?

Thanks.

 

valve seals ''usually'' leak only when engine is cold

edit:**** typo


Modified by mmuller at 3:52 AM 7/30/2004

 

Hrm, interesting.

Well I just put a new set of plugs in today. Drove about a total of two hours on them. Pulled them out and they look ok except the cylinder furthest from the distributer... it's covered in oil I think. Definatly doesn't smell like fuel. I looked down the spark plug hole with a flash light and sure enough that cylinder looks like it's wet. The rest look ok.

So I'm guessing that that last cylinder is leaking oil and causing it to give a really high compression reading. Now exactly what is causing it to leak onto the piston... I have no clue.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Eluzion &raquo;</TD></TR><TR><TD CLASS="quote">Hrm, interesting.

Well I just put a new set of plugs in today. Drove about a total of two hours on them. Pulled them out and they look ok except the cylinder furthest from the distributer... it's covered in oil I think. Definatly doesn't smell like fuel. I looked down the spark plug hole with a flash light and sure enough that cylinder looks like it's wet. The rest look ok.

So I'm guessing that that last cylinder is leaking oil and causing it to give a really high compression reading. Now exactly what is causing it to leak onto the piston... I have no clue.</TD></TR></TABLE>

Could be your piston rings going.

 

Wouldn't you lose compression if it was your rings? Also, wouldn't it burn all the time? I'm pretty sure that last cylinder is the only one burning oil (piston looks wet) and it's giving +20 compression numbers over every other cylinder... and the plug is covered in oil (entire thing including the thread... top part is fine and the spark plug gromets are new). So, I think it's leaking from somewhere, but exactly where I have no clue.

Motor only has about 10,000 miles...

 

the high number in the one cylinder is prolly from either the oil creating a nice seal vs. the other "dry" cylinders, or it could also be from soot/ carbon etc, by-products of the oil burning that have made the effective volume of the cylinder smaller, thus higher compression readings...

Could be isolated within the cylinder head...something like valve stem seals could do this if they are all pushed up

you might have a cracked ring land, which might not show up in reg. cranking compression test cause of the oil in the cylinder, creating a nice seal...the cracked ring land could be causing strange crankcase pressures and oil is being forced in either from the top, bottom, or both

 

Hm interesting. Thanks for the info.

I hope it's not a cracked ring land. I'm leaning towards a problem with the head because of how it burns oil on start up... maybe it's dripping from the head then burns up... and when I rev it it's still burning (oil burns slow as hell from what i've seen). So maybe that's why it doesn't smoke as bad once I've been driving around.

Bleh, guess I gotta dump more money into it.

 

Prolly is the valve guide seals cause it has all the syptoms

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Eluzion &raquo;</TD></TR><TR><TD CLASS="quote">Hrm, interesting.

/ Pulled them out and they look ok except the cylinder furthest from the distributer... it's covered in oil / causing it to give a really high compression reading.
Now exactly what is causing it to leak onto the piston... I have no clue.</TD></TR></TABLE>

valve guide seal