oil in turbo intake - rebuild?
 

I pulled the engine (617.950) from my '79 300SD to transplant into a better body. It's got 245K miles on it so I'd like to replace the sensible stuff while the motor is out of the car. Right now I'm thinking for starters the timing chain + slide rails and
oil cooler lines (weeping like crazy).

What I'm not sure I want to do or not is the turbo which has a bit of oil in the intake when I pulled off the air filter assembly. Is this an indication of a failing compressor oil seal or from blowby coming out of the valve cover ventilation? Do I rebuild while I've got it out? It's a garrett t3 I believe (haven't looked at it real close yet).

Any other suggestions for things that should be done while it's out would also be appreciated.

Thanks

I have the same problem with my 300SD. Basiquely these setups don't have oil catchers and all the blowby gases are literally sucked into the air intake. there is a large vaccum pipe connecting to the air intake that put out a lot of vaccum in the intake box to pull the blow by gases, i always wonder if there could be the culprit. The more modern 617 do't have the set up that way and have a drain pipe going through the air cleaner for oil to return to the crankcase.
My air intake BTW has a 1/2in pool of oil soaking the air filter at all times, so I actually know your pain. I am trying to get a complete 1984-1985 air intake assembly to transplant into the the old 617. But you still have that vaccum tube...

A few of us have just added a good oil seperator to the vent tube before it enters the intake.

http://www.peachparts.com/shopforum/diesel-discussion/163312-crankcase-ventilation-oil-separator-mod.html?highlight=oil+aircraft

Please read this thread
 

RE: Any other suggestions for things that should be done while the engine is out would also be appreciated.


Exhaust leak between engine and Turbo OM617
http://www.peachparts.com/shopforum/mercedes-parts-reference-library/176625-exhaust-leak-between-engine-turbo-om617.html


Have a great day.

The 79SD's don't have any oil separator so its 99% likely to be blowby from the engine. Especially if its pre-turbo as well...

I don't know if this question was answered correctly. The wastegate (boost pressure control) drains into the intake in that same spot.

My blowby is routed differently and this oil is not from blowby. If the wastegate is dumping oil into the intake, preturbo, are the seals on their way out?

There is no oil anywhere in the vicinity of the wastegate actuator. If it is full of oil it is from the breather on the valve cover or the turbo seals.

There is no oil in the wastegate for it to dump.

"there SHOULD NOT BE oil anywhere in the vicinity of the wastegate.."

I opened it up, and it had a fair pool of oil, however. You're saying this is definitely the seals. Right?

No. Oil from the crankcase vent system can make its way into the wastegate body. Even if you haven't had the CCV system working as designed, oil from years ago will stay in there for some time.

What about an 84 300SD, do they have no separator, or do they have the in-the-airbox separator like the one on my 84 300CD, or do they have something different?

I ask because I recently swapped the engine out of an 84SD into my 84CD. The turbo intake from the SD had a LOT more oil in it than the one from my CD, so I assumed the seals were shot and swapped the one from my CD onto the engine before installing it into the car.

Reading the first couple of posts in this thread got me to thinking I might not have needed to do that and that the oil in the turbo intake might have been just from un-restricted blowby/vapor - in which case the "spare" turbo I have maybe just fine...

the models that have an oil seperator (a proper one) have an oil return tube running into the upper oil pan adjacent to the turbo oil drain tube.--you will see 2 tubes running into the upper pan.

Granted this is on a 85 300d, so your car may be different. But my wastegate was spewing oil, literally, and it turned out to be because my turbo drain pipe was stuck too far down into the oil pan. If you've fooled with that plumbing recently, you may want to recheck it. I personally would recommend just going ahead and replacing the seals for good measure. I had to remove the turbo with it in the car, and it was a bear. Good luck.

Answer
 

The air intake oil accumulator drain valve may be plugged with sludge.
check valve MB# 6170180029
#62 in the attached picture.
The part claims to be NLA.
But, it is the exact same valve used inside the vacuum pump three times.





Have a great day.

My '82 SD has the in-airbox type separator.