Strange oil leak- from turbo wastegate actuator? - PeachParts Mercedes-Benz Forum

ROLLGUY · #1 03-19-2021, 10:49 PM

Yes, the waste gate actuator on my 1982 300D is leaking oil! How is that possible? I took the car to the coin-op car wash and cleaned the engine real good. When I got home, there was oil on top of the engine damper shock mount. I put my fingers under the waste gate actuator, and they had oil on them. All of the other suspects in that area (turbo drain tube, air cleaner drain tube, etc) are clean and dry. Anyone else had this problem? I can't imagine how this could be possible, that oil would leak out of the waste gate actuator.....Rich

KJenkins · #2 03-19-2021, 11:36 PM

I have this exact same problem on my 1979 300sd and am also wondering what could be causing this. It's annoying because it keeps dripping on my passenger side motor mount. Hopefully someone will chime in with a solution to this.

dieselbenz1 · #3 03-20-2021, 09:51 AM

Could be blowby getting into the actuator or if the turbo seals have expired then both intake and exhaust will be oil coated. I opened my exhaust flange and it was oil coated. Removing the turbo revealed both turbo seals had given way 240 km 602.

Felching · #4 03-21-2021, 12:23 AM

Blowby gasses or compressor shaft seal are the only possibilities.

h3ffe · #5 03-21-2021, 05:40 AM

Yes, only possibilities are turbo seals or extreme blowby.

ROLLGUY · #6 03-21-2021, 02:23 PM

Well good news= It is NOT the wastegate actuator where the oil is coming from! I examined the turbo and all the inner workings, and there is NO WAY that oil can get anywhere near the wastegate actuator. The oil is definitely coming from the turbo drain tube flange/gasket. I am going to surface the flange on a sharpening stone, and replace the gasket (after I put the turbo back on!).

h3ffe · #7 03-21-2021, 03:21 PM

Good news indeed, Rich. Glad you found the problem.

Quote:

Originally Posted by ROLLGUY

Well good news= It is NOT the wastegate actuator where the oil is coming from! I examined the turbo and all the inner workings, and there is NO WAY that oil can get anywhere near the wastegate actuator. The oil is definitely coming from the turbo drain tube flange/gasket. I am going to surface the flange on a sharpening stone, and replace the gasket (after I put the turbo back on!).

BillGrissom · #8 03-25-2021, 10:05 AM

I recall oil hanging on the waste-gate actuator on one of my 300D's (1984 & 85, but later engine is now 1982). One has the KKK turbo and the other the AR turbo, so the one with the exposed actuator (forget). But, I think the oil was coming from above somewhere, perhaps the air cleaner drain. Both now have the frame-mounted air cleaner (1985 CA), so no more shaking air cleaners w/ leaky oil drain.

ROLLGUY · #9 03-25-2021, 11:34 AM

I worked on the oil leak again, and finally fixed the problem! After THREE times of removing and installing the turbo, I found the source of the leak and fixed it. I actually could have fixed it WITHOUT removing the turbo!
The first time I removed the turbo was to look at the wastegate actuator to see if oil was leaking there. I realized that it was impossible for oil to get anywhere near there, so I assumed oil was coming from the turbo drain tube flange. I installed the turbo, and re-sealed the drain tube. It leaked again, so I removed the turbo once again to inspect it further, thinking there must be a crack in it. I found none, so I decided to check the flatness of the drain tube flange. It was warped, so I honed it flat on a sharpening stone with WD-40. I installed the turbo for the second time, and resealed the drain tube once again. But again, it still leaked. This time, I ran the engine and watched where the oil was coming from. It was coming from above the flange surface. I pulled the turbo once more, and was going to replace it when I noticed that the bolts for holding the center section to the compressor housing were loose! I tightened all four of them, and installed the turbo yet again. I got this turbo a while back, and it was said to be rebuilt. I believe that to be correct, as all the sections were not "clocked" correctly, and the bolts were loose. I should have assumed that the four bolts on the section that I did not have to change the clocking on were loose as well (because they were in fact loose!). The bummer about this entire deal, is that I could have tightened these four bolts WITHOUT removing the turbo!!!!
Well, the good thing is that I learn something new every day!.....Rich

dieselbenz1 · #10 03-25-2021, 12:16 PM

You are referring to the 4 bolts on the exhaust side? Should be no oil in there unless the turbo seal is leaking. Something is not quite right.

ROLLGUY · #11 03-26-2021, 12:25 AM

Quote:

Originally Posted by dieselbenz1

You are referring to the 4 bolts on the exhaust side? Should be no oil in there unless the turbo seal is leaking. Something is not quite right.

There are four bolts holding the center section to the compressor section, that is where it was leaking. I think there are at least five bolts, maybe six holding the hot side to the center section. That joint can be clocked, whereas the compressor section can only go one way. Or maybe one of four ways, as that section is round, and does not matter the clocking?.

dieselbenz1 · #12 03-26-2021, 09:42 AM

The CHRA is similar to the attached if the oil was coming out of the cold side it can only come from the air stream as if the oil separator is no longer working or the CHRA cold seal. Tightening the bolts for clocking may just hide the leak. I just went through this a few weeks ago on my 602. Keep an eye on it.

Felching · #13 03-27-2021, 11:33 PM

The is not oil in the area the bolts were loose. Your compressor shaft seal is leaking and blowing oil into the engine.

ROLLGUY · #14 03-27-2021, 11:50 PM

Quote:

Originally Posted by Felching

The is not oil in the area the bolts were loose. Your compressor shaft seal is leaking and blowing oil into the engine.

Well, then why did the oil stop leaking out when I tightened the four bolts that drew in the compressor section tight to the center section? To me it was obvious that the oil was coming from that joint, as tightening the bolts stopped the oil flow. Besides, the shaft was tight as new because the turbo had been rebuilt, but the sections were not clocked in the proper orientation (or the bolts tight) to fit the mounting on the manifolds.....Rich

Felching · #15 03-27-2021, 11:56 PM

Quote:

Originally Posted by ROLLGUY

Well, then why did the oil stop leaking out when I tightened the four bolts that drew in the compressor section tight to the center section?

You sealed the housing to the body, now all the oil is going into the intake instead of some leaking out.

Quote:

Besides, the shaft was tight as new because the turbo had been rebuilt

Shaft play has nothing to do with the oil seal ring passing oil. You can have gobs of shaft play and not pass a drop of oil or, as in your case, no shaft play at all and be leaking all over the place.
Its a simple piston ring style seal. If it was over-stretched during installation it can lose its "springiness" or break entirely after installation.