Up in Smoke

[Frank Darcy]

I just finished installing a new turbo center unit on my 85 GN. The old turbo was shot. Tons of play. I was getting very low oil pressure even with new main and rod bearings.

I started the car, and it fired right up. I was happily surprised to see my oil pressure go right up to 70 lbs at idle cold. I figured the turbo bearing being shot was dumping the oil pressure. My oil pressure sensor is on a tee right on top of the turbo where the oil feed is. So the car is running fine, no smoke, good oil pressure. I ran probably 5 to 10 minutes and when I added a little throttle, I started blowing incredible amounts of white smoke out the tail pipes.

On the humorous side, my two neighbors came over because they thought the garage was on fire. Is it too much of a coincidence that I could have lost a head gasket? Prior to replacing the turbo, the car was running a little hot and I was getting some bubbling back into the overflow tank. Do you guys have any other suggestions? Is there any reason why the turbo would fail?

 

[esinger]

Prior to replacing the turbo, the car was running a little hot and I was getting some bubbling back into the overflow tank.

Definitely a sign of a blown head gasket. Pop the cap off the radiator and see if you have oil floating at the top of the coolant. Pull the oil dipstick out and see if you have milky looking oil.

 

[Frank Darcy]

I did both things, no oil in the radiator and no coolant in the oil. Everything looks good.

 

[esinger]

Next easiest thing I can think of to tell if there's a blown head gasket is to do a compression test on all cylinders. Start with the drivers side cylinders since their are the easiest to get to.

 

[Frank Darcy]

I will do that. I see there are coolant lines that go to the throttle body. Is there any chance that I could be leaking coolant into the throttle body? I just can't figure how a head gasket could fail at idle with no load. It just seems to coincidental. Thanks for the replies! Frank

 

[sixequalseight]

I had a similar problem on my '84 many years ago...there was a missing seal in the center of the turbo dumping oil into the intake. Don't ask who forgot to put that seal in there...

 

[Jerryl]

I just finished installing a new turbo center unit on my 85 GN. The old turbo was shot. Tons of play. I was getting very low oil pressure even with new main and rod bearings.

I started the car, and it fired right up. I was happily surprised to see my oil pressure go right up to 70 lbs at idle cold. I figured the turbo bearing being shot was dumping the oil pressure. My oil pressure sensor is on a tee right on top of the turbo where the oil feed is. So the car is running fine, no smoke, good oil pressure. I ran probably 5 to 10 minutes and when I added a little throttle, I started blowing incredible amounts of white smoke out the tail pipes.

On the humorous side, my two neighbors came over because they thought the garage was on fire. Is it too much of a coincidence that I could have lost a head gasket? Prior to replacing the turbo, the car was running a little hot and I was getting some bubbling back into the overflow tank. Do you guys have any other suggestions? Is there any reason why the turbo would fail?

Frank,
Glad you got it running.

Most likely, it is just the oil residue in the exhaust system.
The "smoke comment" happened to me as well a few years back. (It is funny now)
I also had a brand new turbo fail in about 18 miles, which was rebuild by a vendor.

If everything looks fine, take is for a 50+ mile or so cruise after you get confortable with "everything looks good". That will clean most of it out.
Are you still running a cat?

 

[Frank Darcy]

Jerryl, I think you misunderstood my last post. I'm still making loads of smoke, I was just answering the previous post about water in the oil and oil in the coolant. All that is good, but the problem is not solved. I am going to do a compression check, but first I am going to drain the anti freeze and add just water. The smoke should be mostly steam at that point and I can elliminate buring oil as a cause of the smoke. I may run the engine for a short time with no coolant, to see if the smoke stops. That will prove that it's coolant coming out the tail pipes. Thanks for the post. I'm think in the end, the motor will be coming out of the car....Frank

 

[Jerryl]

Jerryl, I think you misunderstood my last post. I'm still making loads of smoke, I was just answering the previous post about water in the oil and oil in the coolant. All that is good, but the problem is not solved. I am going to do a compression check, but first I am going to drain the anti freeze and add just water. The smoke should be mostly steam at that point and I can elliminate buring oil as a cause of the smoke. I may run the engine for a short time with no coolant, to see if the smoke stops. That will prove that it's coolant coming out the tail pipes. Thanks for the post. I'm think in the end, the motor will be coming out of the car....Frank

OK, my bad ......... sounds like you got a handle on it.
Let us know how it turns out.

 

[Frank Darcy]

Up in smoke -Update

I pulled the turbo exhaust housing off. The smoke is oil, not coolant.

The turbo spins fine with no end play so it looks ok.

The interesting thing is the turbo inlet exhaust pipe is soaked all the way to the cross over pipe, so it looks like the oil is coming into the exhaust before the turbo. My question is "what seal could I have blown or what seal could I be forcing oil past, so that it goes into the turbo.

It makes sense because when I started the car I was getting 70 lbs of oil pressure at idle. The smoke started coming out when I brought the idle up to 15 hundred rpm. I think at that point I pushed some oil past a seal or damaged a seal. Any thoughts. Any help would be appreciated. Thks Frank

 

[BRAD_PADGETT]

I had a a problem which is like yours. I blew up 3 new turbos due to pressurized block. The turbo seals will leak oil and when enough oil has built up it would through it into the engine and exhaust. This created huge clouds of white smoke. Might be your turbo. Swap it out with a known good one. Good luck- Brad

 

[Frank Darcy]

It's the inlet turbo seal

Brad, thanks for the post. It's the turbo seal and it's dumping oil into the intake. I will be pulling the turbo off and sending it back to Precision for new seals. I will then have to reduce the oil pressure by changing the pressure relief spring. Like I said earlier, I had 75 lbs at idle with the way the pump is set up now. Thanks again. Frank

 

[BRAD_PADGETT]

Frank- after you replace your turbo run Chevron Techron fuel system cleaner. This removes the carbon build up on your piston heads that the oil from the turbo causes. It took me two years after my turbo disaster to discover my subsequent knock problems. Take-care. Brad