S211 Transmission Oil Leak

[Chris Plane]

After have my first Mercedes for a couple of weeks I have sorted a few things but have an oil leak on the transmission. The leak is at the front near where I assume there is a cooler of some type. Does anyone have a schematic of the transmission oil pipework and cooler they could share.

Car is a an S211 270 CDI 2005 VIN:WBD21122162A431031

Many thanks in advance

 

[MJJ]

Chris,

Does this help? Your VIN is not recognised by my instance of WIS/EPC, I think the 4th/5th/6th numeric digits are wrong, but attached is a transmission cooling diagram for the E270CDI model.

Martin.

 

[pgh13]

The cooler is part of the radiator. The connections there have O rings and also at the front are unions where the solid pipe from the cooler join to flexible hose es, just to the left of the 100 and 80, although on that picture they don't look to be detachable

 

[Chris Plane]

Chris,

Does this help? Your VIN is not recognised by my instance of WIS/EPC, I think the 4th/5th/6th numeric digits are wrong, but attached is a transmission cooling diagram for the E270CDI model.

Martin.

View attachment 62234

Many thanks for the information. That is very useful.

On inspection I have a leak on one of the pipes to the cooler. Managed to get some secondhand pipes off Ebay so hope to fit those next week.

Think I will do an ATF, filter and electrical socket change whilst I'm at it.

Hopefully that will sort the issue

The cooler is part of the radiator. The connections there have O rings and also at the front are unions where the solid pipe from the cooler join to flexible hose es, just to the left of the 100 and 80, although on that picture they don't look to be detachable

 

[Wighty]

Many thanks for the information. That is very useful.

On inspection I have a leak on one of the pipes to the cooler. Managed to get some secondhand pipes off Ebay so hope to fit those next week.

Think I will do an ATF, filter and electrical socket change whilst I'm at it.

Hopefully that will sort the issue

Have a look at Fuchs atf oils to save a few quid

 

[Chris Plane]

Oil pan off, cleaned and new filter and gasket fitted. Looked at the electrical connector and whilst when I unpug it there looked like some oil there when I try to undo the 7mm bolt the plug seems to be twisting slightly and I don't want to put too much force on it as I am scared it will twist and bend the pins.

Anyone else had this. Is a small amount of twist in the plug normal whilst undoing the bolt?

Any info most welcome

 

[Wighty]

Oil pan off, cleaned and new filter and gasket fitted. Looked at the electrical connector and whilst when I unpug it there looked like some oil there when I try to undo the 7mm bolt the plug seems to be twisting slightly and I don't want to put too much force on it as I am scared it will twist and bend the pins.

Anyone else had this. Is a small amount of twist in the plug normal whilst undoing the bolt?

Any info most welcome

@Uncle Benz might know the answer

 

[Uncle Benz]

Brace the outside of the electrical socket with a screwdriver against the casing to stop it trying to revolve with the bolt

 

[Wighty]

Brace the outside of the electrical socket with a screwdriver against the casing to stop it trying to revolve with the bolt

I knew you might have an idea

 

[Chris Plane]

Brace the outside of the electrical socket with a screwdriver against the casing to stop it trying to revolve with the bolt

Thankyou. Will do.

 

[Chris Plane]

All,

Many thanks for your help and to the forum in general as i wouldn't have successfully completed the service / repair without the help.

The gearbox electrical plug was replaced ok after the advice above. The leaking return pipe was replaced, ATF was changed, new sump seal, new filter and seems to be all ok.

Whilst running the engine with the covers off it seems i have two leaking injectors (looked like i have bubble bath near the two injectors). Same two the seller replaced. I'm thinking a new copper washer and bolt were not fitted when replaced. Anyway thats the next job. Ordered MB washers (have a slight dome on them i think but not sure which way up the dome goes) and bolts. I understand the torque setting is 7nm + 90 degrees + 90 degrees. I will recut the seats when i pull them (never done this before so any tips most welcome) and clean the threads in the head with a M6 x 1.0 tap. If there is a problem with these i.e they have been over tightened has anyone Helicoiled faulty threads? I used to be a mechanical fitter so have done this many times in the past just wondered if that is the fix for these if the threads are unserviceable?

The engine sounds quite rattly but not bottom end. Will the leaking injectors cause noise?

One last issue. The sump plug had been overtightened in the past and the T40 damaged. Anyways in my wisdom i annealed the copper washer before refitting and tightened it up (not tight at all really) and now it wont come out, doh!!! Is there any trick that can be used before I get a new oil pan and plug? Was thinking grind flats on it to fit a spanner.

Many thanks again

 

[pgh13]

There's a good description here;

I think you can get a chuffing noise from leaking injectors

 

[Chris Plane]

There's a good description here;

I think you can get a chuffing noise from leaking injectors

That is really good. Thankyou