02 GTP, excessive oil usage

My 02 GTP uses 1 1/2 quarts between changes. Has 68,000 on it. I don't think its burning it cause if you rev it in neutral there is no smoke out the exhaust and the tailpipes have zero residue. could a plugged pcv do this? what else could it be. I can smell it when i pull up to a stop sign so i'm wondering if its the oil sending unit leaking excessively.

are u doing any irregular driving then your used to?

Possibly a bad LIM gasket leak or valve cover gaskets. Do you see oil anywhere on the engine?

No, I'm easy on it. This is my work car I drive instead of my 09 Powerstroke. I drive it to work 60 miles one way at 60 mph. Fuel milege is the same too 27.2 in the winter and 28.4 in the summer. It gets dark so damn early I haven't had a chance to look very close, but it has to be a leak. I park on rocks so there won't be any oil spots. What is a LIM gasket?

Sorry for the stupidity. I'm a diesel nut, not a spark plug nut

LIM = Lower intake manifold.

Jesus, I was worried you were gonna say that. I guess that means the supercharger has to come off too. Is there anyway to check it? Like spray WD-40 around it while its running? Or can you not get to it?

LIM gaskets are fairly hard to see while looking at the engine built up. Spraying won't do any good if they're leaking internally.

Great, well....is this a common oil loss problem on these cars or is this something that probably isn't bad?

Common problems are LIM gaskets leaking and valve cover gaskets leaking.

If you can smell it burning I would not suspect the LIM gaskets, though I cant necessarily conclusively rule it out. However, if you can smell it, that means the oil is leaking onto something hot and the only common issue that would experience that would be valve cover gaskets.

Ive only heard of a couple of people with broken or leaky oil sending units and even then it wasnt to where it was burning, it would just leave puddles of oil under the car.

While as Sabre mentioned, the LIM gaskets are common (at least the plastic ones, the newer aluminum ones I have not heard of any issues with them) for leaking, they generally leak coolant into the motor.

Im going to assume for the moment because you said you are a diesel nut that you either have some experience turning wrenches or not afraid to. Correct me if I am wrong.

But working from that assumption there are two ways to proceed, if I hold to my asessment that it is the valve cover gaskets.

1. Just replace the valve cover gaskets and fix the immediate issue, which will cost about $40 for the gasket set. BE ABSOLUTELY CERTAIN you get the valve cover gaskets for the supercharged L67 engine because they are different from the non-supercharged L36/L26 engines. Shouldnt take more than a couple hours to do. You do have to loosen or take off the alternator, I dont recall which, for the rear valve cover and the ICM bracket to get the front valve cover off.

Which leads me to option 2

2. You could get proactive and go ahead and replace the LIM gaskets, provided they havent been replace before and have the newer aluminum gaskets (I suspect not) which will cost about $50. And since you still have to take off the ICM bracket to do the work and therefore might as well take off the alternator too, which then frees up the room to go ahead and do the valve cover gaskets as well. So you could knock out where I suspect the leak may be anyway and take care of where a leak (much more dangerous leak at that) is bound to happen down the road. I cant say, honestly that I know of anyone that has not reached the point of needing to replace the LIM gaskets in a Grand Prix at least.

So those are my thoughts on that.

There is a video how to in the How To section (link at the top) for replacing the LIM gaskets which would be a good one to look at if you decide to take on this work. Honestly, its not hard work, just kinda labor intensive. Oh, and Id get new fuel injector Orings 'cause you would need those as well if you do the LIM.

what about worn out valve seals? has anyone heard of them burning oil?

Sure, but if that were the case there would be some smoke out the pipes which he mentioned he did not have, but if he had not then that would be a consideration.

intake gaskets are not a prob at all. I've done a million chevy trucks with center bolt valve cover heads, they are prone to it. Diesel nut LOL, yes we are all sled pullers around here. I always figured it was the back valve cover hitting the exhaust since there are no oil spots, the underside of the car is clean , and you can smell it. Do you guys all think it could really lose a quart and a half out the valve cover in 3000 miles? you'd think if it was leakin that much that there would be smoke comin out from under the hood.

Skillet,
check the valve cover gaskets it should be dry under the lip of each valve cover. If you cant see run your fingers through there and see if its dry.

There was someone that found a wet exhaust port during a header swap and it was a bad valve stem seal. Spark plug was clean and there was no noticeable smoke coming the tailpipes. He was able to change out the valve stem seals w/o pulling the heads.

If you can smell it you should also look for blue smoke from the tailpipes on initial or cold start up.

I suspect the valve cover gasket as you said you can smell it when you come to a stop....I just changed mine this past weekend as I was going fast stopped quick and threw oil all over my ceramic coated headers...It litterally splashed on them. after replacing it...no more leaky...try that before diggin deaper....easiest first.

Originally Posted by JEFFSGTP

I suspect the valve cover gasket as you said you can smell it when you come to a stop....I just changed mine this past weekend as I was going fast stopped quick and threw oil all over my ceramic coated headers...It litterally splashed on them. after replacing it...no more leaky...try that before diggin deaper....easiest first.

That's what I think too. Start simple. Chances are that's what it is cause they look moist. Of course it would be the rear one against the firewall that is just so easy to get too.

nah, I am leaning towards the front one based on the recall issue they have on them for the engine fires (that street_wolf was so nice enough to edumacate me on recently which is what spawned my replacing my front one....back one might leak but front one seems to get the shorter end of the stick for some reason.

Is that what the recall is for that I got a week ago in the mail? Valve cover gasket?

Yes...the front valve cover gasket wears out, it leaks and on stock motors the oil settles in the manifold area...slowly over time it builds up and when there is enough of a leak/oil presto car fire...all this is amplified by stopping hard as the oil is thrown on the front cover.

I found out the hard way today that is what it was. I hit an effing deer at 4:30 am on the way to work. After I pulled over I could see the smoke coming out from the front of the hood from the oil splashing out. Luckily it was a fawn and it just slid onto the hood and up to the winshield then flew off. Not a scratch left.