Head gasket? E350 CDI C207

[Cirrus]

So I was in the process of selling my E350 CDI Coupe with 150k on the clock and this happened on the test drive...

Oil in the water, etc. Catastrophic HG failure at the worst time possible? The car showed no signs of water in the oil or vice versa having only checked the oil just last week, is it possible to fail quite so spectacularly?

 

[malcolm E53 AMG]

Are you sure it’s the head gasket it could be the oil cooler?

 

[onefortheroad]

Head gasket is usually internal not external. Are you simply assuming here ??

Burst hose more than likely if it is water .

 

[Srdl]

Were you with whoever test drove it? There are well know scams where potential buyers fake the problem by putting oil into the header tank in the hope of getting a greatly reduced price - although your problem looks much more serious to my untrained eye.

 

[Cirrus]

I'm out the country with work so my old man took the fella out for a test drive. Amazingly he has a spare engine from his wife's old E350 that was written off and wanted to take my car away as is, giving me £1000 which sounded suspicious over the phone. However how could he have tampered with it if the bonnet wasn't lifted till they got back from the test drive?

I think I need to check it out myself when I get back on Monday. The burst hose scenario that Onefortheroad mentioned sounds credible.

 

[LostKiwi]

Yes I'd be waiting till I got home, hit it with degreaser then start the engine and see what happens.

 

[Cirrus]

Malcolm, I think the oil cooler seal were beginning to leak just a tiny bit. But how would this cause oil to get into the coolant reservoir?

Are you sure it’s the head gasket it could be the oil cooler?

 

[malcolm E53 AMG]

See post 21 of the linked thread:

A journey into the the infamous Om642 oil cooler leak! - Page 2 - PeachParts Mercedes-Benz Forum

At some point in the not too distant future I am sure I will be treading this road. Thanks for the pics and making it look not as bad as I thought. I

www.peachparts.com

 

[EmilysDad]

Malcolm, I think the oil cooler seal were beginning to leak just a tiny bit. But how would this cause oil to get into the coolant reservoir?

I don't particularly know this engine (despite having one in my ML .... I've never needed to do anything other than have it serviced) but oil coolers in a V are generally water cooled/heated by the coolant

 

[Cirrus]

See post 21 of the linked thread:

A journey into the the infamous Om642 oil cooler leak! - Page 2 - PeachParts Mercedes-Benz Forum

At some point in the not too distant future I am sure I will be treading this road. Thanks for the pics and making it look not as bad as I thought. I

www.peachparts.com

I think, I hope, you've all nailed it. Very likely the oil cooler seals have completely failed and that's how there's oil in the coolant.

Been 10 years since I've pulled an engine or stripped one down so this should be... an experience.

Fingers crossed it is this and not the HG... Great help all, many thanks.

 

[mioba]

A well known weak point on the OM642 is the oil cooler seals.
very time
consuming as the oil cooler is deep in the V.
Plenty on the forum and online.
The seals were upgraded by merc.
If you are happy spannering then all you need is time

 

[Cirrus]

Youtube has a few videos too, as you say seems to be the most common thing along with a spot of black death.

Hopefully 3 days will do the trick, just need to make a shopping list and a torque list.

Ironically I was selling this because I wanted a petrol instead... Had seen a nice 2011 BMW 640i (3.0 turbo petrol).

Timing eh!

A well known weak point on the OM642 is the oil cooler seals.
very time
consuming as the oil cooler is deep in the V.
Plenty on the forum and online.
The seals were upgraded by merc.
If you are happy spannering then all you need is time

 

[mioba]

Keep the post updated, would love to know how you get on.
Good luck!

As a side - never known Of HG failure on a merc.

 

[ajlsl600]

Fix it. Keep it. New stuff has crxp tech

 

[Cirrus]

Keep the post updated, would love to know how you get on.
Good luck!

As a side - never known Of HG failure on a merc.

Will do.
You're right, I can't find anything much googling HG failures on these engines... seems to usually be petrol if any at all.

 

[Cirrus]

Fix it. Keep it. New stuff has crxp tech

If it were a 90s car I might try relocating the oil cooler... maybe we're all getting old here!

 

[ajlsl600]

Buy a known story, somat older u can fix

 

[Doug1234]

I keep looking at the picture you posted and it just doesn’t add up… never seem a similar picture in all the oil cooler threads I have read through and especially going bang all of a sudden and spraying oil everywhere.
How can the oil come out from under the oil cooler and spread upwards like that ?.
Not a diesel leak ?.

 

[malcolm E53 AMG]

Oil cooler replacement is very costly in man hours probably at least 11 hours duration for those that don’t do it every day - my advice is buy a new oil cooler they cost circa £150 but it will save you having to do the job again if it turns out to be warped or leaking

 

[ajlsl600]

Blown oring??