Smoking under Deceleration Please Help!
 

I am having the problem of bad blue (for sure oil smelling) smoke only under deceleration after boost. I have a 6 bolt 2g with a fresh motor, head, and turbo. All has under 2500 miles. Just replaced a headgasket and had the head resurfaced. The valve seals were not replaced because the motor guy said that they looked perfectly fine which makes since because they are at max 2500 miles old. I have a brand new ball bearing scm6152 on it as well and that was replaced since I thought the journal center section was leaking which it was because there was oil coming out of my BOV. I got it all back together and I am having the same problem. I have perfect compression and the leakdown turned out to be 5% on 2 cylinders and 15% on the other 2. 30% is acceptable. I have no clue what to do here or where to go next! Please help. Anyone else have this issue before?

Re: Smoking under Deceleration Please Help!
 

Are you using any sort of catch can or PCV system still?

Re: Smoking under Deceleration Please Help!
 

Yeah I would think pcv system. After boost that will DEFINATLY make it smoke blue and smell like oil. That's what mine did at the cookout cause one of my hoses was kinked. Also where are you feed your turbo from? Maybe too much oil pressure? Or you could still have oil in your IC piping and whatnot that is making it's way in after boosting.

Re: Smoking under Deceleration Please Help!
 

Oil could be coming from the rings, valve seals, turbo, PCV system or could be old oil stuck in the intercooler, i/c piping, or exhaust system.

30% leakdown is not acceptable, maybe for a stock non-performance car that is just driven normally, but not for a performance car. Anything above around 5% is possibly a problem somewhere. I have had cars with bent valves that needed to be replaced give leakdown results of 15-20%.

On the 2 cylinders that were 15% leakdown, where was it leaking to? Valves or rings?

Re: Smoking under Deceleration Please Help!
 

If the two cyls that are leaking down more than the other two are right next to each other, it could be a head gasket or something like that. You could pull the exhaust manifold to have a look at the exhaust ports for each cyl.

Re: Smoking under Deceleration Please Help!
 

valve seals?

Re: Smoking under Deceleration Please Help!
 

First, keep it simple. I'd check your PCV system.

If that is ok, then consider the worst possible scenario of stem seals, or rings.

If your turbo was dumping oil before, maybe there is some trapped in the intercooler or exhaust as others have said before.

Re: Smoking under Deceleration Please Help!
 

Ill ask them which cylinders had the 15%. It is my 3rd HG in 200 miles and I dont want to do it again. The last time I pulled the head and had it resurfaced so that is good and checked the block with no spot being able to accept a 2 tho feeler gauge at all. So it could smoke if the pcv is not hooked up is what you are saying? Ill hook that up first and see what happens. It only does after a little bit after it boosts and it smokes bad when it does.

Re: Smoking under Deceleration Please Help!
 

3 head gaskets in 200 miles? That alone says something. Did you put a steel straight edge on the block? Resurfacing the head sometimes isn't enough. If the block is gone....

Anyway, I"m assuming that you know to use goop on a new seal for that motor. The assembly and torque specs are very involved, I think that the manual calls for four separate tightening sequences to set the gasket.

Re: Smoking under Deceleration Please Help!
 

It isnt like that. I put the copper ics titan on and it held and smoked just like it has and is but that stupid copper head gasket had a slight coolant DRIP out the back of the head. I took that off to put on a stock HG because I thought it was the HG that was making it smoke. The stock HG went because stupid me forgot to retorque the head more then twice and well ya thats that. I then went to a mitsu multi layer and had the head resurfaced before I put that one back on. I used a blue point machinist strait edge and checked the block 100 different angles and ways and no angle could I even come close to sliding a .002 gauge under it. It is all torqued down now and I am not doing another HG because this one is good and am thinking its because of the PCV or valve seals. Could valve seals throw off the leak down that much?

Re: Smoking under Deceleration Please Help!
 

You can take things apart and try to find where the oil is starting. If there aren't signs of burnt oil sludge in the exhaust housing and there isn't oil in the intercooler piping/intake manifold then it's probably something in the motor. Are the tops of any of the pistons wet at all?

Re: Smoking under Deceleration Please Help!
 

Ill have the car back soon and will then check the pistons and what not. I think that I am going to hook up the pcv exactly how it is stock with the fitting on the side of the valve cover going into the intake tube and rehook up the other one the way it was before. Any other things I should check besides intercooler piping, exhaust mani and piston tops?

Re: Smoking under Deceleration Please Help!
 

My car used to smoke right on Accel or after start up as oil pooled on the valves or in the cylinder. That was valve stem seals, and the smoking got progressively worse. You have smoking ONLY on decel. Maybe your rings didn't seat that well? who knows. Do you remember when this smoking started?

Re: Smoking under Deceleration Please Help!
 

This issue only started after I did my headgasket and whatever else I did this spring like the turbo.

Re: Smoking under Deceleration Please Help!
 

Are you running too much oil pressure to your turbo? Oil could be getting past the seals and causing the smoke.

Re: Smoking under Deceleration Please Help!
 

It is a BB turbo with a restrictor.

Re: Smoking under Deceleration Please Help!
 

Which restrictor?

Re: Smoking under Deceleration Please Help!
 

Restrictor in the oil feed line.

Re: Smoking under Deceleration Please Help!
 

Yeah, I dunno about other manufacturers, but when I got mine from FP they had two different size restrictors. One for BB turbos, and one for journal bearing turbos

Re: Smoking under Deceleration Please Help!
 

Well the turbo sales person and the guy incharge of rebuilds were the one that set me up with the restrictor so I am assuming it is the correct one.