W204 Facelift c250d Oil / Transmission Cooler Leak (Photos)

[SH0X]

Hello guys, its been a while. Ive searched all over for info on this but I cant find much (relating to my type of cooler )

The car is a w204 facelift c250 cdi (om651 engine I believe )

There is a trickle leak from the oil cooler - the hoses that connect to the cooler at the top (there are 4)
I know this as you will see in the photos - oil sits on the oil cooler itself.

I cleaned this up and it seemed to have gone away but its back now or perhaps I didnt notice it as much.
It was there 6K miles ago (slight trickle) when I bought the car.

Im wondering if anyone knows about this type of cooler and if a renewal of the seals would be sufficient enough to resolve?

Thanks in advance

 

[Steve@Avantgarde]

Yeah, we have done loads of these, they seem to rot in one corner, the W212 has the same issue too.

 

[SH0X]

Thanks for your reply, Im guessing the transmission oil runs through it so will need draining & refilling when those hoses are removed and seals are replaced.

Im guessing its an O ring where the hoses connect?

Considering a DIY as its pretty easy to access but not sure on the severity of the job!

 

[Wighty]

I suppose the problem is , where is it leaking from

Thanks for your reply, Im guessing the transmission oil runs through it so will need draining & refilling when those hoses are removed and seals are replaced.

Im guessing its an O ring where the hoses connect?

Considering a DIY as its pretty easy to access but not sure on the severity of the job!

I thought Steve said the oil cooler itself tends to rot

 

[SH0X]

Oh I see
I probably read it wrong

The cooler itself looks pretty good (I did clean it up fully )

I suspected the actual metal hoses that pop/bolt on to have O rings and the leak to be trickling from there

I couldnt really determine it, But I can say that the cooler sort of leans forward hence the puddle sits at the front area

it doesnt drip on idle - even revving the car up for a long period of time

only after a long drive will it start the trickle

Thanks

 

[SH0X]

Yeah, we have done loads of these, they seem to rot in one corner, the W212 has the same issue too.

Hi Just wondering if you could give me some more info on this? If its an O ring seal or the actual unit that rots?
Thanks

 

[SH0X]

Any ideas? anyone with experience that could shed some light perhaps?

The left metal line/hose has some play some Im hoping it needed tightening up.

 

[SH0X]

Okie dokes

Looks like im alone on this one even though the cooler is used on several other mercedes models & the c class is probably one of the most common models out there twinned with the what I would assume is very common 2.1 Diesel motor

Might aswell post up what I am finding out from hours or searching and piecing together as it may help someone some day (thats what forums are about right?)

Generic image of the TYPE of cooler

PArt no a0995001100

This is my image

Green is the lower oil line. This has play 0 up down left right& hence I have a slight trickle leak which Im trying to resove

Red points to a circlip - this spins freely

Blue points to what I have found to be a removable part which contains a washer & circlip - its a 19mm hex fitting. I cant find a 19mm spanner but considered checking if this was tight

Im still working things out & what way to approach this.


By the way
I found this link on another forum, which linked to someones page where they listed it under r172 parts diagram links. Its Very good. But doesn't show my type of cooler for some reason when I enter my VIN.

Try it out they show parts diagrams for the whole car (similar to REALOEM BMW)
https://partsouq.com/en/catalog/genuine/locate?c=Mercedes-Benz

 

[mrmb]

If you will post your VIN number I can drop a WIS document with the procedures how to replace it.

 

[SH0X]

If you will post your VIN number I can drop a WIS document with the procedures how to replace it.

Thank you very much. Sent you a PM

 

[Andis C220]

Could you give me some info please as i got same issue now. Bought this car 2 weeks ago and its still under warranty but dealer is 200miles away so thinking if its easy fix then might do it myself. Is those pipes has any fluid in when car is not started?

 

[davemercedes]

There are a few video postings on Youtube - one of them will hopefully show your setup.

 

[Andis C220]

There are a few video postings on Youtube - one of them will hopefully show your setup.

I did tryed to find one but no luck. This video is older version i think as its attached to actual engine. Mine is independent so cant find any info. Even bought haynes manual but dont see anything in there

 

[davemercedes]

Oh... that's a shame and a PITA.

If you can find an auto transmission specialist they can almost certainly supply you with the specific repair kit of gaskets and seals referencing the vehicle model/serial number and at a reasonable price. Years ago I used to use a firm called Van Cleaves (later VanMatic) in North Finchley years ago - I wonder if the proprietor "Pat" is still there? For example they had every Borg Warner part we ever wanted (where I worked we didn't do Mercs).

 

[davemercedes]

Just found their website http://www.vanmatic.com/
- must be worth a call.

 

[C250 harry]

Any luck to sort this out? I have exact problem

 

[Titansilver]

Hi all.
Glad I found this thread.
I have an identical issue on my W204 C220d Auto.

I have noticed an oil leak coming from the Gearbox Transmission Oil Cooler - part number A0995002300 (seems to be similar to part A0995001100 used on the W212 also)

The car is a W204 C220d C220d auto 2014 with 150k miles.
Auto gearbox was serviced by Mercedes main dealer at 100k miles.

See attached photos.
The oil cooler naturally leans back slightly forwards, away from the engine.
The oil pools on the top of the cooler itself.

2 metal pipes and 2 rubber hoses connect to the cooler.
I suspect that an o-ring has perished and is allowing oil to trickle down.

I cleaned up the fluid from the top of the cooler with a paper towel, but it returns after a long drive.

1. Can the o-rings be replaced? Or do I need a new oil cooler and/or hoses?
2. Does anyone have a workshop guide on how to replace this part. Is it a DIY job or more involved?
3. Does transmission oil flow through these hoses whith the engine cold and off?
4. I assume that the gearbox oil would need to be topped up after any work is carried out. Where do I check this?
Do I need a special dipstick and is it temperature dependent?

Thanks in advance
T.

 

[Titansilver]

Any takers?

 

[Darkmagi]

Any takers?

I have the same problem as you, From what I can find online it may be an o'ring in the metal oil line at the front of the cooler, The gearbox oil needs to be topped up after the o'ring has been changed, Its topped up from underneath, If you do a Google search for YouTube videos there are loads off walk through on how to change the gearbox oil but you will just be topping it up so really just the final stage off any video is need, Good luck & if you find a part number for the o'ring let me know as I need one

 

[michaelgmurphy]

Hi all.
Glad I found this thread.
I have an identical issue on my W204 C220d Auto.

I have noticed an oil leak coming from the Gearbox Transmission Oil Cooler - part number A0995002300 (seems to be similar to part A0995001100 used on the W212 also)

The car is a W204 C220d C220d auto 2014 with 150k miles.
Auto gearbox was serviced by Mercedes main dealer at 100k miles.

See attached photos.
The oil cooler naturally leans back slightly forwards, away from the engine.
The oil pools on the top of the cooler itself.

2 metal pipes and 2 rubber hoses connect to the cooler.
I suspect that an o-ring has perished and is allowing oil to trickle down.

I cleaned up the fluid from the top of the cooler with a paper towel, but it returns after a long drive.

1. Can the o-rings be replaced? Or do I need a new oil cooler and/or hoses?
2. Does anyone have a workshop guide on how to replace this part. Is it a DIY job or more involved?
3. Does transmission oil flow through these hoses whith the engine cold and off?
4. I assume that the gearbox oil would need to be topped up after any work is carried out. Where do I check this?
Do I need a special dipstick and is it temperature dependent?

Thanks in advance
T.

This is a 204.202? C220 CDI BlueEfficiency? It seems that in 2011, the transmission in the W204 was changed from the 5G-TRONIC to the 7G-TRONIC-Plus, along with a new style of transmission oil cooler, as per your photo.

Maybe this screenshot from the EPC will help with part numbers for O rings, gaskets, pipework, etc.