Burning through oil
 

I drive a 91 saturn SL with 170k miles on it. The car runs fine, except that I notice that it burns a lot of oil. As in, I have to add oil every 2 or 3 times I fill up.
I've heard some talk about oil seals/rings and about how i've probably got cracked, worn or damaged ones so that oil gets into the combustion chamber.

Oil is not leaking from the engine and I don't have white smoke coming out the exhaust. Although I do notice at night in a cars headlights behind me, I can see smoke exhaust when I accelerate hard, But not when maintaining speeds. (If I have to downshift to accelerate then the effect is much more visible.)

My question is, are faulty rings/seals/whatever the most likely case? Could it be something else? And finally, how major (read:Expensive) of a repair is this to have done. What can I expect?
Thanks for your advice.
-Chip

Oil will produce blue smoke. These older Saturn engines do tend to blow some oil once they get a bunch of miles on them. I'd call 170k a few miles. Most likely, you could get away with a re-ringing of the pistons, and call it good.

Is this an SL1 or SL2?

Valve seals. With that kind of mileage, I'd say valve seals. Ring failure usuallly produces white smoke. Blue smoke at startup and hard accel, I'm saying, is valve seals.

Says I.

Yeah, valve seals are another good diagnosis. Rings won't produce white smoke, rather blue, as they'll allow oil up in to the combustion chamber. I do agree that valve seals could be a problem as well. Hadn't even thought of that...duh!

So just how involved of a repair is this? Under $300? Under $600, More than a grand?

Make sure the car definitely isn't leaking oil. Park it over some cardboard and let it idle - see if you've got any drips.

I'm not sure if this engine has an overhead cam. Overhead cam=more difficulty in most cases.

Replacing the rings is a pretty big job. You have to remove the intake, cylinder heads, oil pan, and pistons/connecting rod assemblies.

Oil leaking past the valves is very likely. The rubber seals start to crack and dry out at that mileage. That's still a pretty big job, however it's less intensive than the rings. The best thing to do is have the cylinder heads replaced.

Dave