turbo and oil separator parts list - PeachParts Mercedes-Benz Forum

JHZR2 · #1 07-20-2003, 06:15 PM

Hi,

The turbo seals and the oil/air separator seals all need to be replaced. I wish to do thisbefore too long.
As I dont wish to remove the turbo, I will go the route of dropping the oil pan to do the oil drain grommet. From doing searches, I have come up with a list of items I believe Ill need. I would appreciate if someone could look over the list to make sure I am complete in my needs, so I dont start the project to find that Im missing stuff...

Turbo drain seal part:
-Turbo drain gasket
-Turbo drain grommet
-Turbo drain O-ring
-Optional lower turbo drain pipe (in case the other one bends)

Oil/Air Separator Part:
-Two O-rings, for theupper and lower ends of the tube (same ones as for the dipstick, correct?

General Parts:
-Oil pan Gasket
-Degreaser

Is this about correct? Any tips to make this go easier? Can I do this without lifting the front end of the car?

engatwork · #2 07-20-2003, 07:37 PM

Parts sound right. I would at least get the car up on some ramps if I were you. You do have to get underneath the car to do this job, especially dropping the lower oil pan.

Ken300D · #3 07-20-2003, 11:43 PM

I'm on the turbo oil drain seal job right now. At first I thought the lower pipe section could be driven downwards out the bottom of the oil pan flange. I thought that was why the lower pan had to come off. Instead, having the lower pan off makes it easy to drive the tube UP using a deep socket as a drift from the bottom.

I kept looking back and forth between taking the turbo off and getting those two upper flange drain tube bolts off. Decided to try one of the turbo-to-exhaust manifold bolts and it wasn't bad at all with penetrating oil. So, the turbo came off.

In doing this I found that the IPO (idiot previous owner) or the IPO's IM (idiot mechanic) had used a significant quantity of RTV sealant around the drain seal. In my opinion, RTV doesn't do well at all around something that flexes and moves around like an O-ring. Better to just let the O-ring and grommet seal on their own. I also found the oil pan sealed with RTV rather than a gasket. This led to finding a few pieces of excess RTV in the bottom of the oil pan. Didn't see any RTV bits in the oil pump screen and sure hope none is anywhere in the engine.

Having the turbo off is giving me an opportunity to look closer at the engine on that side for a oil leak. My theory at the moment is that its oil oozing past a leaky intake manifold gasket. How likely is that? I'd rather think it was the valve cover gasket, but there is a drain channel for that kind of leak that would tend to send it down the back of the engine on the passenger side. This leak is coating the engine its full length below the intake manifold.

Does the intake manifold come off without the exhaust? Or do the two of them together get a one-piece gasket?

Additionally, I found the oil separator drain tube flopping around loosely (once disconnected from the air cleaner housing). It seems a bolt is missing, and I can't really tell where it would bolt up. Gotta get the picture parts book out I guess.

If I get this last leak fixed the car will be just about dry and I can start to rust it out like a normal W123 300D.

Ken300D

JHZR2 · #4 07-20-2003, 11:49 PM

Thanks!

Great info... I am hoping to manage to get the drain bolts off without removing the turbo. I just dont feel comfortable removing that big and important of a piece of machinery in my apartment parking lot. I then have to lay it down on the ground or something...

Did you have any ideas of how to access those bolts with the turbo on the car?

Thanks

JMH

Ken300D · #5 07-21-2003, 07:11 AM

I trouble deciding how to get to those little bolts, and that's mostly why the whole turbo came off the car. That particular place was not leaking, so I don't plan to take it apart.

Ken300D

Ken300D · #6 07-24-2003, 08:25 AM

I was able to perform some further exploratory surgery yesterday evening and removed the intake and exhaust manifolds. Very interesting design in that the same set of nuts (for the most part) holds on both the intake and exhaust manifolds. Also, the individual manifolds are fairly light to handle.

During the removal I found most of the nuts holding the manifolds were rather loose. This helps explain the oil seepage on the side of the engine down from the intake manifold ports. I also found one place where the manifold gasket had split into halves and allowed exhaust gas to escape - it was that loose. EGR valve was totally blocked with carbon, so I can just leave the vacuum attached.

It appears that most of my oil seepage on that side of the engine is not related to the turbo drain seal. Inspection of the drain tube from the oil separator in the air cleaner reveals the inside at the top is dry.

My conclusion is that the oil separator is plugged and non-functional, passing a lot of oil into the intake manifold. The oil then has a tendency to leak out past the loose manifold gasket.

Getting all this fixed should make the engine much dryer, although I will miss the fame the car gets for marking its parking spot.

Question for the group: The oil separator drain tube. Which side of the exhaust manifold support strap (that goes down to the engine mount bracket bolt) does this tube get routed? Inside the bracket on the engine side, or outside? Not sure this is routed correctly on my car, and the bolt or screw has fallen out.

Also trying to find the torque spec for the intake/exhaust manifold nuts. By the way, this is a great design because you can really soak them with penetrating oil if required. American cars of the past have tended to use exhaust manifold BOLTS that sieze into the engine block.

Ken300D

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