Back in January I went to the track one last time on my stock turbo since I knew it was starting to let go. I pushed it up to .9bar and it crept past 1 bar a few times. I was on a 104 mix to avoid detonation with the stock timing. Coming back home from the track me and a bunch of friends stopped at a Taco bell. When I turned off the car and looked back a huge plume of blue smoke was rising through my n1 exhuast.

Logically I deduced the stock turbo had finally let go given the extreme conditions I put it under. There was a thin film of oil in the IC elbow, but not a huge amount. I bought a s5 turbo, and used that for my BNR stage II turbo. Fast forward to a week ago:

The new BNR turbo is on and I start up the car. Everything appears ok. I let the car warm up and go WOT in first and second a few times and head over to a friends house about a mile away. When I get there smoke is starting to come out of my tailpipes, and some was even escaping from under the hood. I pop the hood and see smoke coming from around the manifold/turbo area.

I've always believed that oil control seals don't just give out overnight, but I'd be hesistant to believe a fresh rebuild had a bad bearing or seal in it. I took off the TID and the turbo spun fine and had no oil in it, or in the IC elbow.

What's the best way to definitively say it's the turbo or it's the motor?

 

If your IC elbow doesn't have oil in it then it's not the turbo. (I'm going through this pain right now) I'd say that it's most likely burning the oil on the turbo off. Touching the turbo and downpipe puts residue and oil on it. When I replaced my turbo the first time it took about a half hour for this to burn off. Whenever I go back and touch it for any reason it repeats this process to a lesser extent.

 

I don't know this was a lot of smoke, and was rather thick in nature. I drove it around for 5-10 minutes before parking it back in the garage. I'll drive it around when I get back home this weekend to see if it get's any better, but I have a feeling it won't.

 

A long shot - THe OMP linkage has come off leaving the OMP full open?

 

That was my original thought, but I had the intake off to put in the 720cc secondaries. The linkage is definitely connected.

 

Well my oil seal has failed on me, and I at first believed it was only the turbo that had failed. But with a new turbo on it was evident. Does the smoke burn off eventually after you get the car warmed up? I can drive mine for abour 3 mins and the smoke will stop. Another good way to check is to pull your leading plugs, when you pull them out if you have a bunch of white foamy crap coming out of there than your oil seal is gone. Don't ask me why I know.

- Steiner

 

Well the car didn't start smoking until after I went WOT. I'll pull the leading plugs when I get home tonight, and try cruising without boosting and see what the end result is. I've heard of a few turbo rebuilds failing before, but I'm skeptical that's the problem. I just find it odd how it happened all of a sudden.

 

Further diagnosis:

When I turn the car on and let it idle, it won't blow smoke. When I'm driving the car it doesn't smoke until I come to a stop. If I hold the throttle at 4k for 30-45 seconds there's virtually no smoke until I let off the throttle. I'll pull the plugs when the motor cools off.

 

I have the same exact problem right now. I'm packing the turbo up for a rebuild as I write this (I can multitask!). I just had a rebuilt engine approx 4.5k miles ago it better not be going....

 

Well I guess I'll join the boat... I have a rebuilt motor, started smoking, had turbo rebuilt, now 2 months after turbo rebuild, its smoking again... its fine unless I boost it and get on it constantly... any thoughts?

 

oil control ring failure usually can be detected when the oil has fuel in it.

 

so some fuel can get past the side seals and to the oil control rings eh... well if oil can get into combustion chamber then fuel can get into oil control rings... makes sense man, I'll have to give that a checky-o.

 

Well I diconnected my oil filler neck port from the charcoal cannister piping and have it atmosphere'd now, it seems way better, we'll see how it goes.

 

The oil Control rings were designed to keep OIL from the combustion chamber.....NOT fuel from OIL. SO for those of us that can run stupid rich due to an aftermarket system, it becomes a true reality, when the Oil becomes contaminated and diluted with fuel. Having fuel in your oil doesn't necessarily mean that they have gone bad. But it's a blatant indication that something is wrong.

When the Oil control rings go bad, often they smoke out the Oil filler tube. remove the cap and see if smoke comes out.

 

Oil control rings are used to control oil flow. Some oil must enter the combustion chamber. The oil control rings on a piston engine is used to lub the piston skirt, barrel and provide a seal for combustion and cool the chamber. Oil control rings control oil flow between the housing and rotor. If the engine floods, has low compression, or is running pig rich, fuel will make its way back into the oil pan.

You are correct, oil control rings are not specifically design to keep fuel from entering the lubricating system. I guess you learn that the hard way

 

you gotta remember- we've got 100 psi (on a decent engine) of the fuel/ air charge (when compressed) on one side of the rings (top half of the housing, anyway), and only a 60 psi oil system on the other side...If the rings are worn, which side do you think's gonna win the psi battle?

 

Well I hope this helps. You have 2 oil control O rings. An inner and an outer. The outer one keeps the exhaust from coming into the oil and the inner keeps the oil from getting into the cumbustion chamber. Either way both seperate the oil from getting into the cumbustion vice versa. Here is a way to check your engine for oil control ring failure. Take your turbo/manifold off engine. Clock engine at TDC for a few hours. Then after the wait, turn the engine by hand clockwise and take a flash light and look inside of both rotor housings. If oil puddles up around the apex seal as you turn, you have either a fried O ring or someone put a sping in backwards that built the engine and the spring the didn't lock into place in the rotor. You can also do that inspection for internal coolant leaks.

Bryan@BNR

 

Same problem here.. makes for an interesting smoke show at red lights...


I have about 3k on a rebuilt engine/turbo so I'm really confused as to what it is. I guess my turbo went (i hope its just my turbo).

 

my car does the smoke show at stoplights when cold about 1/10th of the time... it NEVER does it when hot though.. wtf could the problem be?

 

haha, looks like we all have this same fuking problem..

just rebuilt motor, and smoking at red lights, WTF!!!!

im gonna try and rebuild my turbo, and of course we ALL hope its just the turbo..

ahhh, the wonderful headaches turbo cars give...

 

OF the last 4 turbo rebuilds I've sent out, all 4 came back bad. Some leaked oil externally and caused smoke because of the manifold burning oil, some burned oil out the tailpipe, and one even had the compressor nut come off while driving. Needless to say I am not frequenting that turbo shop anymore.

The way I check for oil seals in the engine vs. a bad turbo is to pull the turbo and check the exhaust ports of the engine. They can be read on a rotary just like sparkplugs. Tan equals no smoke from engine. Black equals oil burn smoke or rich burn from engine. IF you have a smoking car and the exhaust passages (prior to the turbo, obviously) are tan, then it is NOT your engine.

Furthermore, I've plugged the coolant holes and used a hose to temporarily mate the oil inlet/outlet from the turbo, rerouted my intake, and fired the engine up shortly without the turbo. Yes, it's damn loud, but it's a definite indicator of whether smoke at idle comes from the turbo or the motor.

 

simple way to fix this issue.... Give the oil pan a vaccum source. Usually you can just run a vacuum line to just infront of the turbo about 3-4 inches ahead of the blades over to the nipple on the oil tube. (thanks to digitalsynthesis and reted for this trick)

 

SO now you want to create a vacuum leak?

 

Digitalsynthesis had the same exact problem he did the same exact thing and it fixed the smoking idle issue. I plan on giving it a shot at the very least.

 

I'm sure it did, but the point is you shouldnt have to do that, the factory didn't do that. IF a turbo is smoking, it's the turbo/builders fault, not the engine's.