S320 CDI engine squeak?/Transmission oil leak

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RichardT

New Member
Joined
Feb 20, 2005
Messages
6
Location
Surrey UK
Car
S320 CDI
I own an May 02 S320 CDI which has developed an oil leak on the transmission, identified by main dealer. Part has been on back order for some six weeks now. Appears to be an external oil leak where loom plugs into the transmission. Surely this is only a question of replacing an o ring? The dealer talked about replacing a plug, but surely the "plug" is the end of the wiring loom? Anyone else had this problem and what was the outcome. What somewhat concerns me is that the car on the ramp next to mine had to have the complete loom changed due to oil contamination. :eek:

Other problem - from time to time there is a squeak like noise occurs on brisk accelleration, could be a slight resonance or maybe belt squeak? It is not consistent, only intermittant. Any ideas?

Mileage about 10.000, owned from new.

Apart from the above niggles, excellent car :bannana:

RichardT
 
RichardT said:
I own an May 02 S320 CDI which has developed an oil leak on the transmission, identified by main dealer. Part has been on back order for some six weeks now. Appears to be an external oil leak where loom plugs into the transmission. Surely this is only a question of replacing an o ring? The dealer talked about replacing a plug, but surely the "plug" is the end of the wiring loom? Anyone else had this problem and what was the outcome. What somewhat concerns me is that the car on the ramp next to mine had to have the complete loom changed due to oil contamination. :eek:

Other problem - from time to time there is a squeak like noise occurs on brisk accelleration, could be a slight resonance or maybe belt squeak? It is not consistent, only intermittant. Any ideas?

Mileage about 10.000, owned from new.

Apart from the above niggles, excellent car :bannana:

RichardT

Hi Richard,

Firstly - welcome to the forums! :) :bannana:

The problem that you have described does not sound un-common. Myself and a few other on here have experienced the very same fault, and on many different models of car. Please see the following thread:

Link

What tends to happen (as I understand it) is that the plug leaks, and gearbox oil is drawn up through the wiring harness. If not discovered quickly enough, this can enter the gearbox ECU and become very exbenzive to repair! :eek:

There is now a revised plug produced to eliminate this problem - and yes, they are quite difficult to get hold of (because of the amount of cars affected).

The plug itself is not very expensive (£5-10 IIRC), and when I had a problem with mine the other month, I ended up ordering one anyway, and then found a guy who could supply and fit the plug together.

As it happens, my local dealership called the other day to say that the plug has arrived, so if you are keen to get your car fixed I might be able to point you in the right direction. ;)

Not sure if this is being repaired for you under some sort of warranty or whatever, but I can recommend a very good independant MB mechanic who would most likely be able to fit this for you at a much better price than the main dealers (and with a better quality of work no doubt! :) )

He is near Kent, but I was pleased with his work and felt that it was worth the relatively simple journey.

Cheers,

Will
 
RichardT said:
Other problem - from time to time there is a squeak like noise occurs on brisk accelleration, could be a slight resonance or maybe belt squeak? It is not consistent, only intermittant. Any ideas?

Mileage about 10.000, owned from new.

Apart from the above niggles, excellent car :bannana:

RichardT

Hi Richard,
You own a very nice car with an exceptional low mileage. There is no excuse for the leak, but I am sure your dealer will do what is right and it will be fixed under warranty. Cars do unfortunately develop problems and hopefully this will be the last.

I just wonder if the 'squeak' is being caused by the low mileage? It could easily be one of the belts, but hopefully the dealer will sort that one out at the same time.

Good luck with the repair,
John
 
Will
Thank you for posting.

The car is under warranty untill the end of May and on Friday I have asked the main dealer in writing to acknowledge our problem and to advise what action they intend to take after six weeks of hearing absolutely nothing and not getting my phone calls returned by the service department.

My understanding is that due to the fact that the oil leaks from around the periphery of the plug, therefore hopefully is not contaminating the loom at this stage I can be reasonably relaxed about the situation. Neither is the leak serious at the moment. However I am becoming less relaxed about the situation as time passes by due to the possibility of the loom becoming affected and I expect better service.

Changing the wiring loom on this car is not an option and I would rather change to a new car. I don't believe a wiring loom could be changed and the car put back in it's original state.

I am well versed in persuing these type of matters as I run my own business and have to pursue negligent suppliers from time to time.

As it happens, my local dealership called the other day to say that the plug has arrived, so if you are keen to get your car fixed I might be able to point you in the right direction
Yes please. :bannana:

The squeak only seems to occur in third gear when the engine is producing a lot of torque (not tyre squeal!) and when it does not happen for a while I tend to forget about it untill the next time. Drive the car normally, no noise. Could even be an air leak on the pressure side of the turbo. However I believe if this was the case it would do it all the time.
Richard T
 
Hi Richard,

Glad to see that the repair is 'in hand' so to speak. Better having it fixed under warranty I would have thought.

RichardT said:
Changing the wiring loom on this car is not an option and I would rather change to a new car. I don't believe a wiring loom could be changed and the car put back in it's original state.

Regarding the wiring loom, I would personally be much more happy if they replaced it?

After all, if they suggest replacement, the technician who makes that decision would obviously not want to change it for fun!

I may be wrong, but I am pretty sure that it is not the entire wiring loom for the whole vehicle - probably a section linking the gearbox ECU and a few other items.

Which dealership is carrying out the repairs? Would be amusing if it was the same one that called me regarding this plug!

Good Luck,

Will
 
Will
HR Owen, Redhill.

Wiring loom - the car having the loom replaced was the whole loom, all 30kg of it. The car was completely stripped and had to be put back together again. Apparently 30 hours work.

In our business we deal with qualified independent engineers who examine vehicles on behalf of garages and general public. I have yet to speak to anyone who believes the car can be put back to it's original state with a complete loom change.

However based on the fact the oil is leaking around the periphery of the plug I don't think at the moment it is something I need to be particularly concerned about other than it needs fixing.

An internal leak that affects the loom would not manifest itself with an oil leak but rather an electrical fault that would affect the operation of the transmission etc.

I remain cautiously optimistic. :)

RichardT
 
the squeak you mention is more than likely the turbo charger
get your dealer to check there trouble diagnosis systems against the chassis no
of your car
good luck
conect
 
Hello, my sister purchased abrand new s320 cdi - it has about 20k(53 plate )on the clock and the auto box is making noises - mb is looking into it.
 
Have spoken with the dealer and gearbox part should be available in a couple of weeks.

The noise is only intermittant, if it was the turbo or gearbox it would happen all the time. Dealer suggested it could be turbo charger (characteristic?) alternator bearing, shroud around turbo, that kind of stuff and will check out at the same time as gearbox part fitted.

RichardT
 
Last edited:
There are some iffey turbos on all CDi engined cars, it's possible the wastegate is sticking partially open so whistling under load or the variable vanes are not adjusting with increased air flow.

The ATf leaking around the plug is common. The seals and plug have been modified and this only seems to have made matters worse.
 
matters worse great i am thinking of lexus next
my old 190e le had 3 things go wrong in 148 k
build quality has defn got far past a joke
 
Dieselman said:
There are some iffey turbos on all CDi engined cars, it's possible the wastegate is sticking partially open so whistling under load or the variable vanes are not adjusting with increased air flow.

The ATf leaking around the plug is common. The seals and plug have been modified and this only seems to have made matters worse.
Worse? :crazy:

Tell me more... :confused:

Will :)
 
Dieselman said:
There are some iffey turbos on all CDi engined cars, it's possible the wastegate is sticking partially open so whistling under load or the variable vanes are not adjusting with increased air flow.

The ATf leaking around the plug is common. The seals and plug have been modified and this only seems to have made matters worse.

The turbo scenario sounds entirely probable, however the production of this noise is it repeatable? or constant or does it only happen ocassionally under certain conditions. Tried to get it to make the noise today and did not happen.

The difficulty is that the noise is not consistant and there does not appear to be any loss of performance. The noise only ocurs when you really press on. My normal style of driving is to back out of the throttle so that the gearbox shifts around about 2500 revs, where the noise does not ocur. It only happens when I take it by surprise so to speak. :D

RichardT
 
RichardT said:
The turbo scenario sounds entirely probable, however the production of this noise is it repeatable? or constant or does it only happen ocassionally under certain conditions. Tried to get it to make the noise today and did not happen.

The difficulty is that the noise is not consistant and there does not appear to be any loss of performance. The noise only ocurs when you really press on. My normal style of driving is to back out of the throttle so that the gearbox shifts around about 2500 revs, where the noise does not ocur. It only happens when I take it by surprise so to speak. :D

RichardT

Some of the variable vane turbos are sticking intermittently, usually losing boost.
 
Will said:
Worse? :crazy:

Tell me more... :confused:

Will :)

The seals have been changed for the second time and the plug once.

Some techs are fitting the old seals because they say the newest ones are more prone to leaking than the older ones?????
 
The oil leak has been fixed :bannana: :bannana: :bannana: well at least the plug has been replaced and the oil refilled.

No squeaks or resonance from the engine at all for some time now, even when provoked. :D

RichardT
 
great how long for ???
why 6 week wait ??
 

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