BoostGuy951

I drove my car to the paint shop to drop it off tonight, and it has been smoking terribly since I reassembled it after a head rebuild. I went back with a MLS headgasket, and I added an oil restrictor for my Garrett. The smoke is whitish grey, and ONLY happens on idle. It smokes erratcally, which is the frustrating part. At one stop light, it doesnt smoke a bit, then at the next one, it covers the entire intersection in smoke. Since I put the head back on, my oil pressure gauge has been pegged out as high as it can go. I know others have installed restrictors with success. The car does not smoke a bit while on boost, or during normal driving. It happens only on idle, and even then, only some of the time.

Any Ideas?

TIA

Alan C.

I had that problem once. Never figured out the problem. It did go away after I rebuilt the engine.

What type/size restrictor did you use?

Good luck.

Ski

Is this when just cold or even at normal operating temp?

Jeremy Himsel

Did it smoke before the MLS gasket and restrictor?

djazzy99

hey boostguy;
i dont know as much about headgaskets and oil restrictors, but i had a situation that was a little familiar to yours. the smoke was also whitish/grey, and it turned out being a little coolant hose which had a little cut on it, and was leaking onto the exhaust manifold. when the coolant hit the exhaust manifold, it started to smoke white! i didnt drive it around to see if it would stop, because i just shut it off and listened for the dripping. maybe when you are driving the coolant doesnt leaks out of that small cut (if thats what you have?) because while i was driving, it didnt happen either, only when i had stopped. the funny thing is, i was taking mine to the body shop for paint as well. wierd....

BoostGuy951

It was a .050 hole in an allen plug.


It actually is only at normal operating temp. It does not smoke when cold.


Yes a little, but mainly when on boost, not while idleing. Now I have no smoke on boost and a ton during idle.

This smoke is all coming out of the tailpipe, so I don't think it is a coolant leak, unless it has something to do with the Head gasket leaking coolant into the cylinders.

Tom M'Guinn

I would start by understanding why the oil pressure gauge is pegged. If the oil pressure is excessive, perhaps some oil is squirting out past the oil inlet on the turbo and getting onto the hot side of the turbo, or is leaking somewhere else and dripping onto the cross-over or header. My car had a small leak in the rear main seal, which would drip onto the cross over pipe at idle, and smoke up the place. Why did it only happen at idle? I think because the drips would get wind-blown down the under belly when the car was moving, keeping it off the cross-over pipe. Funny thing though, that leak seems to have fixed itself.

David Floyd

I don't think a turbo oil restrictor could cause your problem.

Smoke at idle (at vacuum) "usually" is valve stem seals, I hope not in your case since it is a new rebuild, but that smoke would be blue.

White/gray maybe a stuck injector ?

Tom M'Guinn

For some reason, I was thinking about smoke from the engine bay (must be reliving my own experience). If it is out the tail pipe, then this is a good point. Also, if it is white smoke, how is your coolant level? Any change that gasket is leaking around a water port?

BoostGuy951

I think it may be leaking slightly, but this does not smell like the distinct sweet smell of burning coolant to me.

I am also running a Link Standalone, and I don't have the best tune yet, but It isnt so bad as to cause this degree of smoking.

Its possible that the restrictor became clogged by some foreign object in the oil flow. This could explain the pegged gauge.

Danno

Whitish smoke out the tailpipe is coolant. It's coolant that got into your combustion chambers somehow in order to get out the tailpipe. I've seen a couple of heads that had been ported too much and they cut into the coolant passages. This allowed water to enter the combustion chambers. Another way is a cracked head, but I figured you would've caught that during the headgasket replacement.

The other clue is that it's only at idle. This indicates a vacuum in the chambers to suck the water in. Under larger throttle-openings and under boost, there's pressure in the chambers, so water can't make it in.

Questions:

1. How much smoke is there? Is it just a small 2-3 foot column at idle? Or is it a 10-foot tall, 3-foot wide billowing monster? I'll assume the smaller version....

2. Did you spray the headgasket with Coppercoat on both sides? This seals small scratches in the surface of the head and block against water seepage. Gasket scrapers to remove the old gasket material will cause scratches deep enough to get minor amounts of water past the metal headgasket. It all comes down to the Average Roughness of the surface. Best to have something that mirror smooth and flat to within 0.05mm or less.

What can you do now? Find this coolant sealant stuff call Alumaseal or some such name. It will get squeezed through the small fissures that's letting water through and dry up on the other side to seal.

"Its possible that the restrictor became clogged by some foreign object in the oil flow. This could explain the pegged gauge."

This would only be true if the turbo feed line with restrictor was the ONLY oil-passage the oil-pump had to supply. However, since there are multiple passages, including the bypass-passage at the oil-pressure relief-valve, the restrictor is not the problem. Even if the restrictor was completley clogged, there's enough clearance in the bearings for oil to flow and the bypass passage can actually bypass enough to maintain proper oil-pressure even if ALL of the passages were 100% clogged. You've got a problem with your oil-pressure relief-valve or the oil-pressure sender.

With the key to just on before you crank the car, what does the oil-pressure read?

Mark Wo

Nice wheels on the 951. If you don't mind sharing, what are they?

Mark Wo

jimbo1111

When I installed the larger injectors I would get smoke at idle as well. The smoke didn't smell like oil , coolant or gas. I turned out that the injectors were over fueling. Check your idle voltage settings on your piggy back. If that checks out try lowering the fuel pressure a little.

BoostGuy951

No, this is a 30ft x 30ft "There must be a nearby building on fire" type of cloud.

No, I thought it was reccomended not to by Performance Developments.

I am going to see just as soon as I get the car back. I may go over to the paint shop tonight and try this.


I am running 95 lb/hr so I am wondering if the engine at idle requires less fuel than 1% duty cycle on these injectors. That would create a rich condition that couldn't be tuned out. Anyone know the target AFR or Narrowband 02 voltage for idle?

Thanks again for the help everyone!

David Floyd

BINGO I think you have found the cause.