Engine Oil Cooler Gasket - Which one fail first - Coolant side or Oil side ?

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May 30, 2024 | 02:25 AM
  #1  
M271.860 EVO 1.8L.
93,000KM and of 2010 model year, C200.
This will be the same engine as W212 E200/E250 in Asia and Europe and C250 in USA.

As part of preventive maintenance, I told my friend he needs a new complete assy.
I guess he is lucky. If the oil side gasket/seal also failed, coolant in oil will be a reality.
This deformed gasket is coolant side. The coolant loss is very-very little to outside, also masked by another coolant pipe crack/leak


Inside it ( if you open it up ) there is another sealing gasket MB will not sell you, it is not in the EPC.
Aside from that internal 2nd sealing gasket failure , this plastic piece of shi-et filter housing oil cooler combo unit, its plastic material can crack inside too, at that 2nd sealing area.









MB will sell you only item #23 gasket or entire assy #3.



The 2nd gasket set at the assy internal is below, the one without metal frame
https://www.ebay.com/itm/363704421400




Older M271 Supercharged uses metal body and not plastic.
https://www.ebay.com/itm/274930849858





M271.8 Turbo engine uses plastic unit...LOL





This plastic pipe from engine rear azz to oil cooler, item #70 in EPC 3 images up, will also break and leak .




Sorry typo. Item 73 is 70 actually, for below
.



There is one more coolant pipe which will break, guaranteed a 100%.
At right side of engine. Its part of the heater core coolant return back to engine.



==================


Don't get caught too late in the oil + coolant cocktail in engine oil.
All of our engines having engine oil cooler with similar gasket, it will fail under 15 to 20 years old I suppose.

Mine I plan to replace the gasket only, by 2026 or 12th year car age at latest. It is crazy difficult for M276.820 3.0 Turbo to replace that gasket.
https://mbworld.org/forums/e-class-w...r-painful.html


Keep the coolant away from your engine oil
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