Unbelievable Oil Consumption

[philjw90SHO]

Im at a loss, My oil consupmtion is up to a quart every 100 miles. No leaks through the front or rear main seals. No spots on the floor. Hardly any smoke during startup and some smoke during WOT. Cam seals have not been replaced since Ive owned the car but that kind of oil leak would be quite apparant and I cant see any leaks coming from the cam seal area.

Any ideas guys?

Thanks,

Phil

P.S. Since ive owned the car, ive changed the oil every 2500-3000 miles with GTX 10W-30

 

[Racer X]

Man, if you're burning that much oil every 100 miles, it's time for either a rebuild or a new(er) engine.

****, I don't burn that much in 2000 miles!

 

[DHMag]

could be leaking thru the rear cam seal down onto the hot catalytic convertor and burning off. wouldnt leave a mess on the ground.

 

[philjw90SHO]

Quite possible

Is there an easy way to tell?

Thanks

 

[NotSoSlowSHO]

LOOK.

SMELL.

I also think you have a leak. The SHO has LOTS of "hidden" leak possibilities.

Crawl under that thing, do a bit of house cleaning, run it a few days, then crawl under it again to see if you can spot any fresh oil.

YOu may be burning a bit, but a qt. every 100 miles is obsurd. You would be able to smell your SHO from a mile away.

 

[BeautifulDisasterSho]

My 7.5L takes a quart every two weeks and smokes at startup and smokes just a tiny bit all the time now. 1 quart a week on a 3.0 would be insanely impossible without smoking all the time or leaking all over. My guess is the rings. How many miles do you have?

 

[philjw90SHO]

I have 146k on the car and I just had new rod bearings installed. Its been using oil like this for a little while now, before and now after the new rod bearings. All the bearings looked awesome except for cylinder #4 which was due for a change, not sure why.

Im just past my wits end and I'm trying to get to the bottom of this problem.

 

[SHOZ123]

It's probably the oil control rings and your valve stem seals.

2 bottles of Auto-RX over a 7.5k period then a hi mileage oil will fix you up. Or at lest did on my '93.

 

[Carraudio]

I had a QUAD4 in my Grand AM back in the day that burned 3qt every tank. I drove the **** out of it. I was about to get a nice head my dad had done for me when I blew it up. I didn't like that car that much anyway.

 

[pjtoledo]

There once was a story in the SHO Registry about "the cat that ate a SHO",,or something like it. It seems if the substrate in the catalytic converters fail, and crumble, the resulting extremely abrasive dust can be sucked back into the cylinders. That destroys the rings and cylinder walls and would result in really lousy oil consumption. Have you run a compression test?

Perry

 

[SHOMurph]

run a compression test....if not a valve seal is probably failing you.

 

[philjw90SHO]

Ill have to do that, but im still confused about the fact that the car barely smokes at all, leading me to believe its some kind of invisible leak.

About the cat idea, i did have the car emission tested a while ago and it passed, meaning the cats arent totally shot, right?

The engine feels the same as the day i bought the car. It still smokes my girlfriends 94' ATX SHO when we race so the engine doesnt seem to be running on oil instead of gas, and also, i recently took the intake off and cleaned the intake valve chambers, none of the valves looked abnormal, all had normal carbon buildup. Not sure about the exhaust valves though. I have inspected the tail pipes and there seems to be normal exhaust soot inside the pipes.

Thanks for the replies guys, keep em coming.

Phil

 

[DHMag]

have you checked to see if there is oil in your cooling system ?

 

[jedhead]

run a compression test....if not a valve seal is probably failing you.

And make sure you do the test dry and wet. If the compression jumps with the wet test you have a cylinder that is leaking past the rings.

bob

 

[pete315]

my SHO uses a quart every 500 miles. I have a slight leak at rear of back valve cover. I found this out when I did rod bearings. I plan on changing gasket when I get some free time, maybe in 2006! both kids play football so weekends are out. I also notice that if I don't get on it for a while, the first time I bring it up to a 6 grand shift, I see a puff of smoke. it looks more gray than blue but I'm sure engine must have some blowby. after that first shift, I see no more smoke even if brought up to 6 grand again. But with 180,000 miles, I'm not complaining. Oh by the way, the valves have never been adjusted on this car! I did the belt and rod bearings though. Maybe I'll wait until car hits 220,000 miles and I'll change the belt,plugs,and valve cover. I probably will not adjust valves cause I might be opening a can of worms and besides, the car runs mint without any valve noise.

 

[SuperHO]

I use a quart every week and a half to two weeks, but I got a blown rear main seal.....it don't leave no puddles, but I can assure you that the bottom of my car will NEVER rust.....