white smoke under boost

snowb07

New Member
Jul 22, 2003
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soon to be CT
My car is twin turboed. I reorganized the oil return lines and added a scavange pump, that stoped the smoke when idealing.
Now when I run it hard under boost I have a lot of White smoke. Would a breather/catch can setup help, or is this valve float. or ????
 
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It looks white. if it is coolant then it should be a head gasket and I should see oil in my overflow tank and a whitish milkly substance in my oil. Which I am not.
I did however remove my lower intake so I will have to check that out and see if I am leaking anything from there.
 
I've been raking my brain and can't figure out anything that would cause the turbos to smoke under boost. If there are problems with the turbo, they will smoke at idle or when you left off from boost.

Does the smoke have any smell to it? Are you loosing coolant? As said before, white smoke is water, and blue is oil, but I've seen very white looking smoke from oil. Seems quite possible it is an intake gasket. You could always pull the plugs and look for signs of sending coolant through the cylinders. The plug will be 'steam cleaned' if so.
 
Is the white smoke coming from your exhaust? If so, it could be a blown head gasket. You need to do a compression check to see what's going on. If one side of cylinders are lower than the others, then you probably have a blown head gasket. Boost can cause head gaskets to blow because it's extra stress, especially if this is the stock gasket/motor.
 
note

You can easily blow a head gasket, and _not_ get water/oil mixed together. You just need a crack in the gasket between a water jacket opening and the combustion chamber. And it doesn't have to be very big. You might try removing the radiator reservoir fill cap, disconnecting the coils and turn the motor over a few times... do you see any bubbles showing up? If not, reconnect the coils and crank it. Now do you see any bubbles? If yes to either, pull the heads to see what is happening before something really bad happens, like the crack getting larger and hydraulically locking the motor under power, which will bend a rod or crank in a heartbeat.
 
I'm still not sure why everyone thinks it is a head gasket, I'd be very surprised if it is.

First of all, in boost or high loads, you will have higher pressure in the cylinder than is in the cooling system. This will tend to blow combustion gasses into the cooling system and they will vent out the radiator cap if the pressure gets too high. This does NOT allows for coolant to enter the cylinder at a high rate.

A headgasket or cracked cylinder wall will produce a lot more smoke and a lot more noticible problems at idle or deceleration. This is where cylinder pressures are the lowest and there can be a substantial vaccume in the cylinder which draws in the coolant. I usualy first notice a blown head gasket because 1 cylinder will begin to miss at idle (from the water in the cylinder). This does NOT sound like what the origional poster is experiencing. This is from experience, I have blown head gaskets and last fall cracked the cylinder wall of my 2.3T.
 
I've been raking my brain and can't figure out anything that would cause the turbos to smoke under boost. If there are problems with the turbo, they will smoke at idle or when you left off from boost.

Does the smoke have any smell to it? Are you loosing coolant? As said before, white smoke is water, and blue is oil, but I've seen very white looking smoke from oil. Seems quite possible it is an intake gasket. You could always pull the plugs and look for signs of sending coolant through the cylinders. The plug will be 'steam cleaned' if so.

I agree with the "if there is a problem with the turbos they will smoke all the time"
so I am going to add a catch can system and reseat the lower intake on a new gasket and see if that helps.


Heh well prepare to fry your brains some more :D

My old TT GT would ONLY smoke under boost...due to a bad seal in one of the turbos. See when you go WOT it would heat up any oil that was leaking out of the seal. Seal would apparently leak only under high oil pressure. So if you just revved it out easy, it still wouldnt smoke at all...until you went WOT and the EGTs got hot enough to burn the oil. then it would smoke and would keep smoking for about 10 seconds after you let off the gas and the smoke would just be rolling off the back bumper with a long trail behind me...looked rediculous and I literly "smoked" many would be opponents on the highway. :lol:

I would start driving away from them and then they would disappear into my smoke trail :rlaugh: .

One poor soul started out behind me in a race....well I got throgh 3rd and not too bad, but off into 4th and EGT temps start to rise after im starting to pull away and then he had to let off cause he couldnt see where he was going :rlaugh: :lol: :rlaugh: :lol: Safe to say I smoked him!
 
haha, good story. I have been living with a bad exhaust seal on the turbo of my 2.3 lately. It would smoke TERRIBLY after letting off from high boost. Something about spinning a tiny T3 to the edge of the compressor map at 20psi and then slamming the throttle shut and it wasn't happy. I just did a rebuild this weekend, so hopefully it will hold up well now. I guess I was too hard on mine to let oil accumulate in the turbo.

The only time I smoked during boost, was because of an oil return line leak. It would dump oil on outside of the exhaust and during a long pull, it would progressively start burning the oil off the outside as it heated up. but that doesn't count because it is burning off the outside of the exhaust as opposed to coming out the tailpipe.
 
how did you rebuild your turbo seals. I bought one of the t3/t4 rebuild kits as that is what my turbos are. and I cannot see where the gaskets they sent in the kit would fit anywhere.

Did you take any pics when you rebuilt your. if so can you post them. thanks
 
Sorry, no pics. I did get some instructions in the email with my rebuild kit that has good pictures. If you want to PM me your email, I can forward it to you. The instructions are for a dynamic compressor seal.

There are 3 possible types of compressor seals your turbo can have. If your rebuild kit has parts that don't look like anything you took out, then you probably got the wrong seals. I'd say the exhaust seals cause most problems, so replacing the exhaust seals and new bearings to get rid of the shaft play can help a lot.

Brian

how did you rebuild your turbo seals. I bought one of the t3/t4 rebuild kits as that is what my turbos are. and I cannot see where the gaskets they sent in the kit would fit anywhere.

Did you take any pics when you rebuilt your. if so can you post them. thanks