Would you retrofit this PCV seal?

[JHZR2]

I’m trying to reduce some seepage from the front in y OM642 MB diesel in my 2008 ML320 CDI. These engines are known for oil cooler seals but that’s not it. It’s coming through the intake.

The PCV/breather is convoluted in this engine. The cam has a hollow end, a vent system with centrifugal oil separation, a seal for the cam, and a PCV breather puck that has a spring loaded diaphragm.

Here’s a photo of the breather cam from sprinter forum:

Here’s my PCV puck:

It feeds into the turbo intake and if not sealing well, puts oil into the intercooler, piping, dpf, etc.

The PCV puck is just a diaphragm with a spring. Not very complex. It can’t be tested by rattling it or by sucking or blowing on it.

That puck connects to a right angle fitting that goes from the hollow cam. There is a seal. Installed it looks like this:

Removed, the hollow cam looks like this:

The right angle connector looks like this:

The seals aren’t available per the FSM for this part. You can buy the whole part from MB for $89.

Later or different versions of this engine had a one piece PCV valve that just connected to the cam, no two-piece setup. That one has a replaceable seal set. I bought the set.

It is very, very close to the seal in the right angle breather I have.

To be continued…

 

[JHZR2]

So the two seals and the bore in the metal part are very close.

It looks ok.

But it’s a retrofit, not an oe repair. The OE solution seems to be to replace the piece. I’d hate for something to not be right, and the engine ingest the seal or something.

Supposedly this seal helps keep a lot of oil from the intake.

It seems ok, looking for other thoughts. Concerns??

 

[clinebarger]

Diesels have historically been vented via a road draft tube, My '97 Dodge 12V was vented to atmosphere, CCV systems have been problematic in my opinion especially when coupled with EGR.

 

[Boomer]

For $89, but the single piece.

 

[JHZR2]

Diesels have historically been vented via a road draft tube, My '97 Dodge 12V was vented to atmosphere, CCV systems have been problematic in my opinion especially when coupled with EGR.

Yeah, my Cummins is the same. All my MB diesels have had a breathing system, most have EGR.

Even my early 80s turbo diesels have a breather with an oil separator that drains to the sump. Later ones have a puck similar to the valve here, but built into the valve cover.

It certainly does contribute to egr soot buildup…

 

[JHZR2]

For $89, but the single piece.

I actually confirmed elsewhere that a sprinter tech uses the part I have to get the seal and retrofit the other style PCV that is more expensive.

Because of that I think I’m going to give it a go.