With these cars, at 100k miles, is oil consumption more likely to be caused by brittle valve seals, or bad rings--assuming that the car was well maintained. I know this is a hard question to answer, and that a leakdown test will answer it quickly. Just wondering what your experiences have been. I'm hoping that my car is using oil at the valve seals (mostly), so that the problem would be helped by...a set of new heads. I've thought about breaking out the old compression tester, but know that that is likely to tell me nothing related to oil consumption. What do you think?

 

well if you are going to take the heads off, that will tell you right there because you can turn the bottom end by hand and see which cylinder if any are not scraping the oil back down.

 

do you burn oil constantly or only at start up? if its only at start up then its prolly valve seals! valve seals going isnt uncommon but if its rings then its time for a rebuild.

 

mine burns puffs on deceleration,it did this from about 120.000 kilometers,it has 213.000 kilometers now(canadian),no diference,still minor puffs,I've heard that if it burns on throttle,its your rings,if it burns on deceleration,it most likley your valves,but this is just what I've heard,even though,my car still runs awsome!

 

^^^ yea i think that is right my 88gt burned on accel and it was the #8 cylinder, haha i had a blue cloud behind me in that thing.

 

Thanks for the quick replies, folks! Well, as near as I can tell, it only smokes on decelleration; although it is very difficult to tell while actually driving it. When driving, I never see any smoke no matter how hard I run the thing. Since I have no friends, I set up a video camera behind the car, and the just gunned the motor to save Jesus. At low/mid rpms, I could see nothing. High up in the range, I saw what looked like trailing smoke on decel. It was hard to tell at what point the smoke was actually coming out though. It's also hard to tell when the car is not under load.

By the way, what do places charge to run a leakdown test anyway?

 

i had alot of water in my pipes and my friend said when i rev'd it shot out about 6 feet.. i was surprised because of all the cars ive owned ive never seen water get shot 6 feet from the pipes lol.

does this mean i have alot of back pressure or something?

 

twisted,I've trailed behined other stangs,I've seen a few doing the same thing,I think if it dosn't blow on acceleration,its not THAT big of a deal,mines been doing it for 4 years now,I can live with an acasional puff here and there,until its realy rebuild time..

 

oh yea,when I said deceleration,I ment,after hard throttle,then coasting in gear say like down a hill,thats when mine does it..

 

i have a lot of water that come out of my pipes to, it only does that untill the exhaust warms up, it does that because of the hot exhaust and the cold pipes.