Turbo center housing is leaking and smoking
Thread Starter
Joined: Sep 2003
Posts: 3,742
Likes: 1
From: Queens, NY
d'oh! Turbo has been smelly and smoking
This started the past few times I've taken the car out and I thought it may have been the return pipe gasket. I pulled the turbo and found this:



pics are a little blurry, but you can see where it's black compared to where the bolts are clean and shiny. It is oily in there, and very sooty where it's been burning off. I also did scrape a bunch off. What's causing this? Turbo is VERY low mileage; under 1000 from BNR. Is there too much pressure from the oil feed? I've read mixed answers and can't determine whether or not I should put a restrictor/tiny hole on the feed or leave it open.
Please help me!
This started the past few times I've taken the car out and I thought it may have been the return pipe gasket. I pulled the turbo and found this:



pics are a little blurry, but you can see where it's black compared to where the bolts are clean and shiny. It is oily in there, and very sooty where it's been burning off. I also did scrape a bunch off. What's causing this? Turbo is VERY low mileage; under 1000 from BNR. Is there too much pressure from the oil feed? I've read mixed answers and can't determine whether or not I should put a restrictor/tiny hole on the feed or leave it open.
Please help me!
Thread Starter
Joined: Sep 2003
Posts: 3,742
Likes: 1
From: Queens, NY
Yup. Did not do any shim trickery or anything.
I did do the bypass pellet. When cold, the pressure is 70+PSI until it drops to normal levels at operating temps.
Do you think it's because of no restrictor?
I did do the bypass pellet. When cold, the pressure is 70+PSI until it drops to normal levels at operating temps.
Do you think it's because of no restrictor?
is return pipe blocked?? do you have the crankcase breather ventlines blocked??
mazda / hitachi stick a restriction the CHRA where it feeds the front 270
.. some shops pull it out and allows more oil to the front.. and in effect less to the rear
i run no pellet.. and have modded oil pressure that is beyond gauge when cold ( 100 + psi )
and when its healthy.. it does not leak at all
the only time my turbos have leaked there ( and nothing as bad as that !! ) is when they are worn out in 270 and in shell bearings and or rear seal and in need of a refresh
adding a banjo modded to 2 x 2mm holes does slow down the issue.. but also amounts to faster bearing wear under some conditions
( ie.. at idle .. inside the turbo it may be below design flow and pressure )
if its a fresh rebuild then your CHRA may have been worn and required oversize bearings ..
but ,,by the volume of mess i suspect you instead have an oil return issue and should check for rags in return pipe or blocked vent line
mazda / hitachi stick a restriction the CHRA where it feeds the front 270
.. some shops pull it out and allows more oil to the front.. and in effect less to the rear
i run no pellet.. and have modded oil pressure that is beyond gauge when cold ( 100 + psi )
and when its healthy.. it does not leak at all
the only time my turbos have leaked there ( and nothing as bad as that !! ) is when they are worn out in 270 and in shell bearings and or rear seal and in need of a refresh
adding a banjo modded to 2 x 2mm holes does slow down the issue.. but also amounts to faster bearing wear under some conditions
( ie.. at idle .. inside the turbo it may be below design flow and pressure )
if its a fresh rebuild then your CHRA may have been worn and required oversize bearings ..
but ,,by the volume of mess i suspect you instead have an oil return issue and should check for rags in return pipe or blocked vent line
Last edited by bumpstart; Mar 29, 2013 at 08:57 PM.
Thread Starter
Joined: Sep 2003
Posts: 3,742
Likes: 1
From: Queens, NY
Turbo is pretty low mileage like mentioned. Oil return definitely not blocked. I suspected the leaking gasket, hence I removed it all. Everything was clean though. All ventilation in place.
I run an e-bay special supply line. There is no restriction.
I should also mention I found some "goo" in the turbo outlet. Oddly, it was not in the turbo, but in the silicone elbow.
I run an e-bay special supply line. There is no restriction.
I should also mention I found some "goo" in the turbo outlet. Oddly, it was not in the turbo, but in the silicone elbow.
Thread Starter
Joined: Sep 2003
Posts: 3,742
Likes: 1
From: Queens, NY
Case is vented properly; i have the stock components in place. I will try removing the cap, or just popping the upper line off. It's very nice out, I'd really like to drive!
Trending Topics
Thread Starter
Joined: Sep 2003
Posts: 3,742
Likes: 1
From: Queens, NY
It's all rebuilt from BNR! Very low miles 
I did a home depot racing restrictor, and I popped a vent line off the top of the oil filler neck and took it for a spin. 5 minutes out I smelled the usual smoke so I pulled over, and it was still smoking in the same area. On the way back, I hit the gas a few times (boosting) and the smoke was/is gone now. When I got home I let it idle and didn't see or smell anything. Maybe I just have a turbo that needs the restriction in oil feed? I will know/learn more of it as I drive the car next time. I hope it's gone!

I did a home depot racing restrictor, and I popped a vent line off the top of the oil filler neck and took it for a spin. 5 minutes out I smelled the usual smoke so I pulled over, and it was still smoking in the same area. On the way back, I hit the gas a few times (boosting) and the smoke was/is gone now. When I got home I let it idle and didn't see or smell anything. Maybe I just have a turbo that needs the restriction in oil feed? I will know/learn more of it as I drive the car next time. I hope it's gone!
No restrictor needed. Promise. I've gone through everything with my BNR.
Stock or even slightly bumped up oil pressure you won't need the 2mm restrictor. One issue I ran across was the feed line gasket leaked when it came up to temp. Also the factory hardline for the feed can develop hairline cracks over the years. I think RotaryEvolution is correct about the seal or thrust bearing.
Stock or even slightly bumped up oil pressure you won't need the 2mm restrictor. One issue I ran across was the feed line gasket leaked when it came up to temp. Also the factory hardline for the feed can develop hairline cracks over the years. I think RotaryEvolution is correct about the seal or thrust bearing.
Last edited by -RotorDemon-; Mar 30, 2013 at 09:37 PM.
Thread Starter
Joined: Sep 2003
Posts: 3,742
Likes: 1
From: Queens, NY
I have to drive it more to know for sure if it's gone. I will also go over the vent system and make sure it's working (nothing clogged). Feed line is new, that's not leaking (the leak is underneath, out of the CHRA).
thanks
thanks
Thread
Thread Starter
Forum
Replies
Last Post
trickster
2nd Generation Specific (1986-1992)
25
Jul 1, 2023 04:40 PM




