1993 300D 2.5 Turbo Diesel

Hey guys, I am really frustrated since I am stump right now.

Originally my turbo was leaking in the front. So i decided to purchase a used one by a reputable vendor. I installed it, and it sucked all the oil through the exhaust via the back bearing.

Ok so I returned that turbo and received another one through a different vendor that claimed the turbo was good, no leaks, tested.

I just received that turbo yesterday and spent 3 hours this morning installing it. Guess what happen? All the oil leaked again through the exhaust in like 4 minutes.

Is my luck that bad for me to have purchase 2 bad used turbos or am I doing something wrong here? Please help, I am so frustrated right now.

Thanks

Is there wet oil in the exhaust manifold?

Sixto
MB-less

Yes, a lot. The rest of the oil just drained down the exhaust.Is it possible the drain is plugged or something?

I think what sixto is getting at is that the turbos may not be the problem.


Your engine may be leaking oil into the exhaust. This could likely be from the valves, headgasket or rings.

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How would I diagnose if there is a leak somewhere else?

Here is What I know so far is that behind the back(internal) propeller inside the turbo is full of oil. Also, the manifold connection where it meets the turbo has oil in there. The exhaust where it connects to the turbo is full of oil. There are no visible oil leaks around the headgasket or anywhere else I see. The front of the turbo is clean.

From what I understand the turbo receives oil from the pressure valve on top, the oil passes through to lubricate the propeller in the turbo. The oil is then supposed to be gravity fed through the oil drain valve on the bottom. The back part of the turbo is not suppose to have oil in there. Is this correct?

Exhaust from the cylinders enters the manifold. If oil leaks by the valve stems or a break in the head gasket, it will get pulled into the cylinders.

Likely, the only way to get enough oil in to the cylinders so that liquid remains in the exhaust is from a failed headgasket or piston rings.

Failed headgaskets are much more likely on this engine. Especially near the front.

A failure does not need to be visible externally to leak that much oil into the cylinders.

Back part of the turbo (exhaust turbine) should not have oil.

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Make sure the drain is clear as well. Just pour some oil down and make sure it flows well.

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Ok. I will check the drain.

Would a failed headgasket cause oil to be present in the back of the turbo? Or does this indicate an issue with the turbo or drain plug?

If this is the furthest upstream you see oil, that's where to start. Remove the exhaust manifold then check which of the five exhaust ports is oily. If it's #1 and/or #2, consider a bad head gasket. If it's aft of those cylinders, it's more likely a worn exhaust valve stem seal or guide. It could be a worn exhaust valve stem seal or guide in #1 or #2 but that's more likely to be a bad head gasket.

Did you replace the head gasket or have work done on the valves recently?

Sixto
MB-less

I have never replaced the head gasket before or have done work to the valves.

So I took the manifold off and it looks like you were right.

Ports1 -3 were oily. With that said, is there any topics or links out there with instructions on how to replace a head gasket, valves, etc...?

Also, do I have to take the head to a machine shop before I replace the gasket?

Thank you all so much....

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