Thread: Heavy white smoke from exhaust, Need advice

Hi all,

I bought a 99 GTP a few weeks ago and have been loving it, Until Yesterday when I noticed a very heavy white smoke from the exhaust. Temp got up to 210* at idle, But cooled off after i started driving again and revving the enigne up to around 3k produced a heavy white cloud that you could not see through. Strange part is smoke does NOT smell like coolant or oil, but I am losing a good amount of both. I think the oil is being lost via a leaky valve cover gasket. Smoke was very white, no bluish color at all, and there are no puddles under the car making me think im burning it.

I've spent all day researching and browsing the forums, and found so much conflicting information I had to make a thead. My best (uneducated) guess is headgasket or LIM gasket.

My notes:

No oil in coolant or coolant in oil
No air bubbles surface with rad cap removed, but level does dip maybe an 1/8th in when revving, and raises again as rpm's drop.
temp stays consistent and cool while moving, and spikes a bit at idle.
No loss of power or fuel economy
Putting a piece of paper up to the exhaust makes droplets on the paper in 30 sec

It doesnt pour smoke contantly. Sometimes ill rev it and see no smoke at all, but after letting it idle for 30 sec or more i get heavy smoke on the next rev and a steady "puff puff" from the exhaust at idle.

from what I gathered, the LIM gaskets are poorly designed and notorious on these engines. They have coolant and oil passages, both prone to leaking. Can coolant enter the combustion chamber by a failing LIM gasket? I'm guessing it gets into the head and eventually makes its way into the chamber?

Going to do a compression test right now will post results. I've already ordered a leak down tester,but it won't be here for a few days.

Desperate for any suggestions/ideas. Sorry for my lack of knowlege, very new to these engine.

Thanks in advance.

It's very likely to be the intake gaskets or bad upper intake manifold. They can cause coolant to just be burned, and still have none show up in the oil.

If your engine runs fine you probably won't find any bad compression readings. As far as I know, when coolant if just burned and not in the oil, the EGR tube in the upper intake manifold is usually the issue. It heats up enough to deform the plastic and cause a leak. Dorman's new manifold comes with a metal sleeve to prevent that from re-occurring.

These?

Well this is what you'll need
Buy Felpro Intake Manifold Gasket Set MS 98014 T at Advance Auto Parts

Amazon and ebay should have it $15-$25 cheaper if you want to look there. Part # MS 98014

And while you are there... do this!!

http://www.grandprixforums.net/how-mod-lim-46931.html

Originally Posted by 02NavyBlue

bad upper intake manifold.

How does a supercharger aka metal UIM have a typical NA motor plastic manifold failure?

Originally Posted by 02NavyBlue

the EGR tube in the upper intake manifold is usually the issue. It heats up enough to deform the plastic and cause a leak. Dorman's new manifold comes with a metal sleeve to prevent that from re-occurring.

The EGR tube is never the issue for a UIM failure, the UIM is. But again, doesn't apply because we are talking about a supercharged motor.

Originally Posted by dbextreme

And while you are there... do this!!

http://www.grandprixforums.net/how-mod-lim-46931.html

Not going to argue about modding a lim, however it's likely unnecessary since he's charged.

I've seen a few things leak coolant into the intake on a SC motor.
1. TB spacer: the fix, throw the spacer away and get a new gasket.
2. Coolant o-rings at the LIM to SC gasket. Not common, but it can happen. Do LIM and plenum gaskets, clean the tb, you'll be all set for years.
3. TB gasket leak: it's paper, it can leak. Swap it out.

Originally Posted by BillBoost37

How does a supercharger aka metal UIM have a typical NA motor plastic manifold failure?

I was being vague about a diagnosis, I try to do that if people searching for a similar problem want answers. Usually I put in parenthesis "doesn't apply to you" but I forgot.

Originally Posted by BillBoost37

The EGR tube is never the issue for a UIM failure, the UIM is. But again, doesn't apply because we are talking about a supercharged motor.

That was bad wording on my part, I know how it goes.

Thanks for clearing it up Bill.

White=water/coolant. Blue=oil. Black=unburnt fuel. If you're loosing both, it doesn't eliminate them. And it doesn't have to smell like coolant to be coolant when coming from the exhaust.

Could be LIM, I remember mine looked REALLY bad at only like 80k miles. Also it could be TB gasket, mine failed going down the highway and dumped enough coolant down my intake to stall when I was cruising at 70mph, I got very lucky it didn't hydrolock or cause any damage.