[lze475]

I have an E91 325d M57 and yesterday I found fresh (not burnt) oil in the exhaust, most likely it's the turbo, but it broke for a reason. Is it actually the turbocharger or should I check the crankcase breather first? The car hasn't lost any power which is why I have hope that the turbo isn't dead yet.

[Gemini562]

Finding fresh oil in the exhaust does point towards the turbo, but checking the crankcase breather (CCV) first is a smart move since it's a common issue and easier to fix if it's the culprit. The fact your car hasn't lost power is a good sign, it suggests the turbo might still be okay for now. If the CCV isn't the issue, then yeah, you might be looking at a turbo problem.

[Scubudo]

I think the valve cover gasket is another place that can dump enough oil into the intake to push unburnt oil through the motor cause that.

[lnxguy]

Originally Posted by Scubudo

I think the valve cover gasket is another place that can dump enough oil into the intake to push unburnt oil through the motor cause that.

Not really. A failed VCG will pressurize the crankcase and cause all sorts of fun things. Usually it's an external leak outside the engine. If he was pushing that much oil through the intake for it to drip out the exhaust he'd have bent rods and or an engine runaway.

[Scubudo]

Not true. I had an issue with my Provent that was draining into a T in the dipstick. When I originally installed it, there was a one-way valve in the drain line. About a year ago I noticed that I had a couple of drops of oil on my driveway every time I parked. I discovered that the drain line had disconnected from the Provent side of the one-way valve in the drain line. I decide to replace the drain hose that was getting stiff and left the one-way valve off (after all, it wasn't leaking much when disconnected). Well...that was a big mistake because the next day my low oil light kicked on. I added around 2 quarts of oil on an unlevel part of my driveway. The next day I made it about 5 miles (not even highway speeds) before my low oil light kicked on. Yet I didn't have oil running out from under my car. I thought about it a little more and convinced myself that since my driveway wasn't level the dipstick must not have read correctly. I added almost another 2 quarts to get it back to full. When I went to restart starter kicked on and immediately stopped. I thought about things for a moment and pushed again, and it started right up without a miss or any sign there was a problem. I drove about 5 low speed miles again and the low oil light came back on. At that point I realized I had a big problem. I pulled the intake manifold and found it full of oil. I pulled the intercooler and it was full of oil. I was having a lot of trouble believing that I hadn't blown a turbo because they too were full of oil...but the timing of everything pointed to the CCV. With all of the oil in the intake side of the turbo, I had to pull them off to clean them, which is when I discovered oil coming out of the exhaust manifold and into the exhaust side of the turbos as well. Believe me I was shocked because I wasn't even blowing smoke out of the exhaust or running rough. Everyone insisted that it had to be a turbo seal. After cleaning everything up I plugged the drain line to the dipstick and hooked the Turbo's back up without the intercooler connected and started the engine briefly...if it was a turbo seal that was leaking expected to immediately have oil start pouring out of the turbos...but not a drop spilled. Since everything was already apart, I proceeded with the delete project I was about to do (which included changing the valve cover gasket). I have had no oil loss since. When trying to sort things out I found a video of an M57 that had a blown head gasket and yes, it was leaking oil from everywhere (including into the intake and out the exhaust manifold).
So... although I am fairly certain that I was sucking oil through the CCV, I can't totally rule out valve cover gasket (and I am not going to hook the drain line without a one-way valve to find out).

[lnxguy]

Originally Posted by Scubudo

Not true. I had an issue with my Provent that was draining into a T in the dipstick. When I originally installed it, there was a one-way valve in the drain line. About a year ago I noticed that I had a couple of drops of oil on my driveway every time I parked. I discovered that the drain line had disconnected from the Provent side of the one-way valve in the drain line. I decide to replace the drain hose that was getting stiff and left the one-way valve off (after all, it wasn't leaking much when disconnected). Well...that was a big mistake because the next day my low oil light kicked on. I added around 2 quarts of oil on an unlevel part of my driveway. The next day I made it about 5 miles (not even highway speeds) before my low oil light kicked on. Yet I didn't have oil running out from under my car. I thought about it a little more and convinced myself that since my driveway wasn't level the dipstick must not have read correctly. I added almost another 2 quarts to get it back to full. When I went to restart starter kicked on and immediately stopped. I thought about things for a moment and pushed again, and it started right up without a miss or any sign there was a problem. I drove about 5 low speed miles again and the low oil light came back on. At that point I realized I had a big problem. I pulled the intake manifold and found it full of oil. I pulled the intercooler and it was full of oil. I was having a lot of trouble believing that I hadn't blown a turbo because they too were full of oil...but the timing of everything pointed to the CCV. With all of the oil in the intake side of the turbo, I had to pull them off to clean them, which is when I discovered oil coming out of the exhaust manifold and into the exhaust side of the turbos as well. Believe me I was shocked because I wasn't even blowing smoke out of the exhaust or running rough. Everyone insisted that it had to be a turbo seal. After cleaning everything up I plugged the drain line to the dipstick and hooked the Turbo's back up without the intercooler connected and started the engine briefly...if it was a turbo seal that was leaking expected to immediately have oil start pouring out of the turbos...but not a drop spilled. Since everything was already apart, I proceeded with the delete project I was about to do (which included changing the valve cover gasket). I have had no oil loss since. When trying to sort things out I found a video of an M57 that had a blown head gasket and yes, it was leaking oil from everywhere (including into the intake and out the exhaust manifold).
So... although I am fairly certain that I was sucking oil through the CCV, I can't totally rule out valve cover gasket (and I am not going to hook the drain line without a one-way valve to find out).

When a VCG fails it pressurizes the crankcase which restricts the oil feed from the turbo. That oils leaks past the seals and into the exhaust.

You're also going to have a crap load of oil on the intake side of things (IC full, etc)

If your engine was eating that much oil, you would have hydrolocked, or had a runaway or blown that thing to bits. The tell tale sign of the oil getting into the exhaust from the seals is that the engine was still running ok.

[Scubudo]

I went back and double checked what I posted at the time and you are correct, it wasn't as much as I stated above. It was more like 3/4 of a quart I was low... but even that was a guess because I was pouring it from a 5 gal container that was almost empty.
I guess the best way to tell would be to find out how much oil needs to be lost to set off the low oil light.
On another thread I posted the picture of oil in the exhaust side of the turbo.



As you have done on this thread, you chimed in that my turbo was toast. However, it clearly was not because I cleaned them up and put them back on. Nothing else was done to them and there has been no oil consumption since. However, for oil to get from the engine to the tail pipe, it would be unlikely unless he is deleted and straight piped. Another question is whether or not he has experienced any oil consumption...because to get from the turbos to the intake was clearly enough to set off a low oil light on my vehicle twice.
The only way I can envision why I didn't have a runaway or catastrophic hydrolock is that when I pulled the intake off, there was oil dripping from within it. Had it been atomized; it would have been much more flammable. So, I think that while it was parked that enough oil dripped into one of the cylinders to briefly hydrolock against the starter, and once the cylinder was pressurized, enough oil managed to pass through one of the valves between the 1st time I tried to start and the second. Otherwise, how else would oil have reached the exhaust manifold? I have never pushed the start button and have the engine start to crank and suddenly stop either. Does yours do this? What else would cause this? It wasn't a battery issue because the battery had no trouble cranking the second time or since.

[lnxguy]

I chimed in because you don't understand what happens when a VCG fails. That oil he saw isn't going through the entire engine then back out the exhaust.. It's from the turbo seals like I mentioned above. I also didn't tell the OP his turbos were toast, not too sure we're you're getting that from?

And if you want to go back to your thread about 'Missing oil', I told you the exact same thing, your catch can caused the pressure build up which pushed oil past the turbo seals..

I think you grossly overestimated how much oil actually made it into the engine from the intake side and contributed to what you saw in the exhaust. I think you got really lucky in the scenario you mentioned above if that's indeed what happened.

[BB_cuda]

Originally Posted by lnxguy

I chimed in because you don't understand what happens when a VCG fails. That oil he saw isn't going through the entire engine then back out the exhaust.. It's from the turbo seals like I mentioned above. I also didn't tell the OP his turbos were toast, not too sure we're you're getting that from?

And if you want to go back to your thread about 'Missing oil', I told you the exact same thing, your catch can caused the pressure build up which pushed oil past the turbo seals..

I think you grossly overestimated how much oil actually made it into the engine from the intake side and contributed to what you saw in the exhaust. I think you got really lucky in the scenario you mentioned above if that's indeed what happened.

Inxguy - I'm a witness to what happened on Scubudo's car. His turbos are fine. I can't attest to how much oil he really pushed into his intake as I wasn't there for that but if the oil light comes on, you gotta be low. He borrowed a couple tools from me, cleaned it up and life is now good for him again. Indeed, he was lucky.
An aside: I removed the oil catch can from our E70 after having heavy white smoke. I later learned that the can was very full and was sitting at a slight angle. When my wife hit the brakes, she would get bad smoke. The E70 collects oil appreciably faster than my E90 does.

I have contemplated removing the OCC on E90 too as I read over on FB forum that guys are backing off and running OE style again. Being deleted, the oil won't make the pudding anymore as no EGR carbon dust to cake up with. The only negative I can see is the intercooler will collect oil. Since, he E90 doesn't collect alot it won't be near as bad in the IC.

I have considered TDIwyse's idea long ago of drilling a hole at the IC's bottom to drain oil from and put a drain screw back into it. A hole with proper self tapper screw is the idea. I don't want to go full blown and put a welded boss onto it and put a machine screw in it though. That would require pulling IC all the way out to take to a welder. I can normal weld (have a MIG) but can't TIG weld aluminum.