How do you remove the breather pipe grommet?
 

I'd like to replace the rubber grommet AKA: seal ring (#35 - A 601 016 01 63) that holds the breather pipe (#41 - A 602 010 06 70) in the valve cover (#5) on my 91 OM602.

Short of breaking the 90 degree connector I'm unable to find a way to remove the breather pipe from the seal ring (red arrow).

What's the secret to disassembling these two items without breaking them (a new breather pipe is $35)?

http://i46.tinypic.com/nbokev.jpg

You can cut - at this stage of brittleness it's more like saw - the grommet at the valve cover line. I think the inside half is accessible without taking the valve cover innards apart. There are some bits riveted to the underside of the valve cover. Hopefully they're not in the way. On the plus side, whatever is in the way should catch the inside half of the grommet and keep it away from the valvetrain.

Sixto
87 300D

Y'all don't wanna hear this , BUT
 

Mayhaps,
Take the Valve cover OFF
and use some kind of soft dowel to drive it out from underneath

Since you're gonna replace the ring anyway,I'd soak it with silicone for a few
days,First

[All those OLD Rubber compounds and Plastico suffer so much Embrittlement
from the years of Heat and exposure to degraded petroleum products.]

Once you've got the Plastico pipe OUT of the Grommet,the Hard Part is Over.

The Pictogram reveals the Iceberg's actual threat.

Glad to read there is no physical restriction beyond deterioration of the old grommet. I'll grab a new seal ring and then pull the valve cover just to be safe.

Thanks!

A related question: If blow by is vented through the breather pipe, where does the engine get fresh air from? Oil fill cap by chance :-\

Fresh air comes from the air cleaner through the turbo. MB and the EPA believe diluting clean air with blow by and exhaust gas is a good thing.

Sixto
87 300D

sixto after reading your response it's clear my question wasn't clear.

The question should have been, "If crankcase vapors are vented / exhausted through the breather pipe, how does fresh air enter the crankcase".

As for mixing crankcase vapors with fresh air before the intake, I'm OK with that (provided any oil has been removed first). For me the last thing I want is my car to create a smelly atmosphere at idle - some of us remember cars from the pre PVC era :o.

is this a serious question?

air in pushed into the engine via the atmosphere and or the turbo pulled through the air filter. it enters the crank case when the multithousand psi explosion occurs, and a small percentage of the air squeeks past the rings.

100% serious and as I noted to sixto, my question could have been clearer.

Pre pcv engines had an up (exhaust) breather and down (intake) breather. Engines now use a PCV and (on a gasser) vacuum to pull fumes from the crankcase - this replaces the old up breather. So to prevent a vacuum from forming in a new engine (certainly not mine w/280K :)) there must be some way to let air into the engine - this would replace the old down breather. What is that and do the OM602's have one?

Answer
 

Break the old grommet.
Vacuum the chunks out.
Install the new grommet.


.

The engine vacuum pump is one source of fresh air into the crankcase.

There's a pinhole in the valve cover that sometimes bleeds oil. I don't know if that's a fresh air breather of some sort.

Sixto
87 300D

1mm pinhole in the rear passenger side of OM602/603 V.C.
 

Emergency Pressure Relief.[Only works OUTBOUND]

I'l look for that hole this weekend while replacing the grommet. Thanks guys!

Here's what goes on in the valve cover - http://www.startekinfo.com/StarTek/outside/12253/program/Engine/602_603/01-040.pdf

I didn't realize valve covers are different for naturally aspirated and turbo engines.

Sixto
87 300D