M112 oil breather (EGR) covers

1995-Present : E200, E220D, E240, E290TD, E300, E300TD, E200, E240, E250, E280, E300, E320, E420, E430, E350, E500 E55AMG, E63AMG & incl. blueTEC & BlueEfficiency, All CLS models
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Model you own: w204
Location: Melbourne

M112 oil breather (EGR) covers

Post by Ivanerrol » Sun 25 Nov, 2018 12:15 am

Needed to reseal both engine breather covers on the W211. Only 80K's up and already leaking.

Apparent when having the moon roof opened - nasty burnt oil smell wafting in via the roof.

I did this with my and a friends W210.
Here is the drivers side - it was leaking and seeping onto the exhaust manifold - creating burnt oil smell.
This is an easy DIY job. But.
(a) You need to scrupulously clean all the old RTV silicon from the cover and the valve cover mounting.
(b) You need to use some good quality RTV - Stealership stuff is $80.00 - Pematex The right Stuff is $40.00
(c) There are some aluminum bolts in the covers - these must be replaced. - Stealership $20.00 - Bunnings $3.30
(d) The fastening bolts are only tightened lightly - up to 4nm - get a low reading torque wrench to do the job.

You can get some appropriate wire brushes at Bunnings for $6.00 to clean the channels in the covers.

Clean the cover well
I spoke to some contacts at the stealership. They do these reseals consistently on M112's. A mechanic I spoke to had 3 reseal kits in his tool box.
The mechanic emphasized the absolute need to clean all the old RTV out. This takes all the time doing the job.
He also mentioned that they are constantly redoing the job on cars that have had a reseal done at non Mercedes workshops (they don't spend the time cleaning out the old RTV).

Here's a link to Fupabox's video on instructions on doing this job.

You may need to replace the air hoses going into the covers. It's not a big job to do this.
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Re: M112 oil breather (EGR) covers

Post by AMG » Sun 25 Nov, 2018 12:02 pm

Actually, that really is the preferred method on all ohc engines, not just mb-brand-specific.

The older engines like m102/3/4 m116/7 which have a nitrile type gasket also benefit from this practice.

clean all the gasket mating surfaces out with acetone and remove all sealant. apply new sealant, gasket and affix cover to engine, ensuring no oil has migrated onto the mating surface.

Never re-use a gasket. Ever.
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