White and blueish smoke

[Slo2gn]

I have a 97 GST with a stock T25.. I noticed about a 3 weeks ago that I was smoking any time I was decelerating or just before i would come to a complete stop. It happend just after I installed the Megan racing catless DP... So I figured the turbo was on its way out so I ordered from GpopShop a stock t25 rebuild kit and rebuilt the turbo. I had no problems rebuilding it. (Note the car was Leaking oil at the Oil pan at the time) Also my Motor has a full rebuild on it with less than 250 miles.. (Full gasket kit New pistons Rods, oil pump valve seals, HG, ECT.) after Installing the turbo and a new oil pump gasket I went for a slow drive got into 5psi in 2nd gear and decelerated and still smoking WHITEish Blue ish smoke out of the Exhaust. However when I parked I still had a slight leak near my oil pan..

Is my turbo starving for oil? I am lost..

 

[DSM1G90]

Valve guides and seals are bad, or not installed/functioning correctly.

When you suddenly de accelerate, you've got sudden vacuum built up in the cylinders causing oil up in the head to be drawn down past guides and seals.. and that's what you see.

You mentioned a recent rebuild: did you use corrective break-in methods with using dino break-in oils and frequent oil changes?

If you used synth oils, the rings will never seat against the cyl walls to achieve the proper metal to metal sealing.

Plus, with only 250 miles on the new motor, nothing has seated yet, thus you're going to see oil for a while until things get seated down correctly.

 

[stolenracer]

Have you done any oil changes since the rebuilt motor? You are still breaking in the motor at only 250 mile. Hopefully you are doing very frequent oil changes with a conventional 10w-30.

As far as if the turbo is leaking oil, pull off the intercooler pipe and check for oil. with a recent rebuild i doubt it is but something might not be seated correct.

Personally i would continue to break in the motor while paying close attention to everything. if its still smoking around 1000 mile mark do a compression check and leakdown test. Valve seals could be bad, rings could be bad. A lot of things can happen even on brand new parts

 

[Slo2gn]

Thanks Guys I'm going to check into the Valve Seals it seems Logical that maybe they could be bad or installed incorrect if Not... I switched from Conventional to mobile 10w30 synthetic at 150 miles is that bad? also I did use Lucas break in additive with the conventional in the beginning.

 

[Calan]

Rings should be pretty well seated well before 250 miles...mostly within the first 50 if it is broken in properly. Leaking valve stem seals usually smoke right after start-up and then taper off, but are still a possibility.

I would suggest doing a leak-down and compression test so you don't have to keep guessing, and pull the IC pipe to look for oil in the intake as stolenracer suggested.

 

[Slo2gn]

can somone give me the approx PSI of what each cylinder should be on a stock 7 bolt just rebuilt with oem pistons and rods @ 0.20 overbore

 

[stolenracer]

150+ with all Pistons being within 10% of each other. I have seen new motors with 200 across the board and some with 160 all depends on how well your rings have set. Your rings should be pretty much set by now but can still seal up more as you continue to drive.

 

[Phantom DSM]

On a stock new motor per service manual with 8.5 compression max was listed at 178 psi, you can use a figure like that to estimate. Keep in mind this all fluctuates on health of motor and your rebuild. Compression testing usually shows better number once rings are seated after good break in. It is somewhat normal for a new motor to consume a bit of oil, but after rings are seated not much oil should be getting past the rings to be smoking. The way you describe it, barring no turbo seal issue, it could be the valve seals. Try compression test on motor after a good drive and see numbers you get to pinpoint the issue a bit better. You can move to a leakdown test for better diagnosis.

 

[Slo2gn]

Thanks I'll give it a shot I gotta rent a leak down tester from Auto Zone or somewhere..

 

[Calan]

can somone give me the approx PSI of what each cylinder should be on a stock 7 bolt just rebuilt with oem pistons and rods @ 0.20 overbore

You could just read the article I linked you to, which has all of that information in it.

 

[Slo2gn]

You could just read the article I linked you to, which has all of that information in it.

Thanks just clicked into it.

 

[Slo2gn]

I recently pulled the motor out and checked all of the valve seals they all seem to be good... However I did buy new supertech valve seals and arp head studs and new head gasket. Any thing else I can check while I have the motor out.

 

[WES_393]

What kind of head gasket did you use? Did you have the head surface checked or machined?

 

[Slo2gn]

The entire short block is machined. New piston rods pump water pump etc. I was using a oem composite HG and just got a new one..