C43 Gearbox oil leaking into passenger side foot well (BEWARE)
#1
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C43 Gearbox oil leaking into passenger side foot well (BEWARE)
Hello all and happy new year,
I have been viewing posts on this site for a few months, its a great site and very useful, so I have finally signed up and tried to help.
I don't want to cause alarm but I say BEWARE because my friend at an MB specialist has seen this problem and told me to check as worst case it damages the ECU which can also damage the gearbox.
The first time I looked was last week and that's probably the first time anyone's has looked....its a 1998 model which I have own for 6 months. In the passenger side foot well under the sound proofing material and underneath the alloy panel held on by three plastic 10mm nuts which on my car has a computer labelled by siemens (I think its the Gearbox ECU) and also a relay attached to the alloy panel.
I found oil on the wires and plug to the ECU and also about a table spoon amount in the foot well which I have all clean up. My question is how did it get there because I can not physically see oil along these wires to any point apart from near the ECU and would like to point out is up side down and means the oil is travelling up. THE OIL MUST BE TRAVELLING INSIDE THE WIRES UNDER PRESSURE? from the gearbox and will eventually get into the ECU. I have sealed the ECU up in a plastic bag around the wires and will check soon again if there is oil inside the bag and if there is no oil outside the bag then my theory is correct, although I may be wrong.
Has anyone experienced or checked it takes about a min to lift the carpet and undo the alloy panel?
I have been viewing posts on this site for a few months, its a great site and very useful, so I have finally signed up and tried to help.
I don't want to cause alarm but I say BEWARE because my friend at an MB specialist has seen this problem and told me to check as worst case it damages the ECU which can also damage the gearbox.
The first time I looked was last week and that's probably the first time anyone's has looked....its a 1998 model which I have own for 6 months. In the passenger side foot well under the sound proofing material and underneath the alloy panel held on by three plastic 10mm nuts which on my car has a computer labelled by siemens (I think its the Gearbox ECU) and also a relay attached to the alloy panel.
I found oil on the wires and plug to the ECU and also about a table spoon amount in the foot well which I have all clean up. My question is how did it get there because I can not physically see oil along these wires to any point apart from near the ECU and would like to point out is up side down and means the oil is travelling up. THE OIL MUST BE TRAVELLING INSIDE THE WIRES UNDER PRESSURE? from the gearbox and will eventually get into the ECU. I have sealed the ECU up in a plastic bag around the wires and will check soon again if there is oil inside the bag and if there is no oil outside the bag then my theory is correct, although I may be wrong.
Has anyone experienced or checked it takes about a min to lift the carpet and undo the alloy panel?
Last edited by £ C43 £ AMG £; 01-08-2008 at 09:39 AM.
#4
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#5
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Thread Starter
MERCS owners in the U.S.A seem to have the best range of mods availible
just to also say that mercs in the U.k
are limited in mods, I just managed to fit and source some 19" and the rest are personal touches. Whats wrong with the U.K a supercharger kit fitted is about £20000 thats 3 times the value of my car?
nothing to say for the germans apart from they make them and they do it well
![off topic](https://mbworld.org/forums/images/smilies/ot.gif)
nothing to say for the germans apart from they make them and they do it well
![Smilie](https://mbworld.org/forums/images/smilies/smile.gif)
Last edited by £ C43 £ AMG £; 01-08-2008 at 03:35 PM.
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#12
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ML320
its the elect connector on the trans rt frt side,, this is a common issue with all the other models also ,with the 722.6 transmission,e class,mls slk,sl,c class,s class
if you get to it before the fluid gets into the ecu it will save you a lot of money, replace the connector and clean the connector with some elect cleaner
if you get to it before the fluid gets into the ecu it will save you a lot of money, replace the connector and clean the connector with some elect cleaner
#13
hey buddies, if i put the car on a hoist and stand under the car can this oil leak be spotted from down under looking at the trans?
can this bad rubber seal be changed outside the car disconecting the wires or must it be changed from inside the cabin>?
where does this oil come from?= if there is any leak then the cabin must smell like oil inside, mine does not do it yet!
cheers
#14
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Thread Starter
hey buddies, if i put the car on a hoist and stand under the car can this oil leak be spotted from down under looking at the trans?
can this bad rubber seal be changed outside the car disconecting the wires or must it be changed from inside the cabin>?
where does this oil come from?= if there is any leak then the cabin must smell like oil inside, mine does not do it yet!
cheers
can this bad rubber seal be changed outside the car disconecting the wires or must it be changed from inside the cabin>?
where does this oil come from?= if there is any leak then the cabin must smell like oil inside, mine does not do it yet!
cheers
To see if you have this problem you don't need to get under the car you only need to do this to fix the conector /seal is on the gearbox . Just look in the footwell location where you will find the gearbox ECU.............. THE OIL IS TRAVELLING INSIDE THE PLASTIC COVERING OF THE WIRES because the oil is under preassure from the gearbox where the seal has become weak. The harder you drive your car the more preassure will be created in the gearbox and the more oil will get through......... and also depending on how badly worn the seal is. This is simple fix but would probably cost around £3000 if oil gets into the ECU and then also damages the auto box.
Last edited by £ C43 £ AMG £; 01-14-2008 at 08:32 AM.
#15
hi to ya all, i dont get it, how the oil travels on the wires=? how does it come out from the transmission=? is it the ATF oil or what=? and how does it get inside the wire and travel the long way into the passenger footwell and then drains the gearbox ECU=?
MAY I GET A proper explanation please, of this crappy mercedes problem!
mercedes do they know anything about this problem>?
should i cover the ecu with a plastic bag or something?
thanx for the proper input.
happy driving with all your c43s
MAY I GET A proper explanation please, of this crappy mercedes problem!
mercedes do they know anything about this problem>?
should i cover the ecu with a plastic bag or something?
thanx for the proper input.
![drive](https://mbworld.org/forums/images/smilies/driving.gif)
#16
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ML320
i`ll try to explain it the best i can, the connector on the transmission starts to leak trans fluid, at the connector the fluid gets pulled into the wiring by the flow of elect current and travels through the wiring to the components on that circuit the ecu is usually the first to start seeing the fluid, this is a slow process and happens over time
#17
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Thread Starter
hi to ya all, i dont get it, how the oil travels on the wires=? how does it come out from the transmission=? is it the ATF oil or what=? and how does it get inside the wire and travel the long way into the passenger footwell and then drains the gearbox ECU=?
MAY I GET A proper explanation please, of this crappy mercedes problem!
mercedes do they know anything about this problem>?
should i cover the ecu with a plastic bag or something?
thanx for the proper input.
happy driving with all your c43s
MAY I GET A proper explanation please, of this crappy mercedes problem!
mercedes do they know anything about this problem>?
should i cover the ecu with a plastic bag or something?
thanx for the proper input.
![drive](https://mbworld.org/forums/images/smilies/driving.gif)
If you checked the ECU location behind the foot well ally plate and you have found there is no oil on the plug/wires on the ECU then don't worry, you don't need to replace the connector on the gearbox, becuase it has not gone weak
![thumbs](https://mbworld.org/forums/images/smilies/thumbsup.gif)
![Frown](https://mbworld.org/forums/images/smilies/frown.gif)
As tbenz says its a slow process you and may find it takes many hours of driving for oil to work its way down the wiring loom toward the ECU.
Mine has done 100 000 miles...... but still quick as the wind though.
Last edited by £ C43 £ AMG £; 01-16-2008 at 08:31 AM.
#18
just to also say that mercs in the U.k
are limited in mods, I just managed to fit and source some 19" and the rest are personal touches. Whats wrong with the U.K a supercharger kit fitted is about £20000 thats 3 times the value of my car?
nothing to say for the germans apart from they make them and they do it well![Smilie](https://mbworld.org/forums/images/smilies/smile.gif)
![off topic](https://mbworld.org/forums/images/smilies/ot.gif)
nothing to say for the germans apart from they make them and they do it well
![Smilie](https://mbworld.org/forums/images/smilies/smile.gif)
#19
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1997 C280 Sport
is this still open because when my car got rain water from clogged rain drains I was drying the carpet and found oil right under the place where you guys r talking about but not any where close to the ecu. can some one help me if I post some pictures
#20
The transmission control unit (TCU) is attached to the metal plate under the carpet on the passengers side. The oil leaks from the transmission connector, and wicks up the wires to the TCU, eventually damaging it. The fix is to replace the connector sleeve, and dry the wiring harness. Ignoring this problem will cost you $$ later.
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1997 C280 Sport
ok I don't understand some are is the TCU that gets damaged some are saying is the ECU, are they the same thing. can someone please help me out because i found oil on the wires to the ecu too now. where is the rubber seal located on the transmission?
#22
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ECU is under the hood, the TCU is the one in the passenger foot well.
#23
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12' W204 C63 AMG coupe "T-Rex", 12' W451 Smart Fortwo Pulse (99' W202 C43 AMG sold)
Go read post #79 in this thread: https://mbworld.org/forums/c36-amg-c...ml#post4919922
#24
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1997 C280 Sport
thank you DRBC43AMG now I don't know if our cars look similar underneath because I have a c280 inline 6 but here is a picture from my transmission is the connector the one circled in red. I can't tell from the pictures of the thread that you showed me and again thank you very much
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12' W204 C63 AMG coupe "T-Rex", 12' W451 Smart Fortwo Pulse (99' W202 C43 AMG sold)
No, thats looks like the plug going into the passenger footwell. The dreaded plug is on the gearbox. Look at the other end of the cable and you will certainly find it.