CLK 430 Limp mode

[MrDan23]

Mercedes CLK 430 2000
Problem:- Limp mode

This is a follow on from http://www.mbclub.co.uk/forums/new-member-introductions/163440-introduction.html

Im hoping to keep this thread alive and updated regularly until i solve the problem to help other users.

I have the car booked in for diagnostics tomorrow.

so far the clk is in limp mode with no dash lights illuminated.

I've checked under the passenger side carpets and it was covered in oil

I had wiped most of it up before taking a pic.
I always thought ATF was red rather yellow.

I wasnt 100% sure where the oil was coming from so removed the white metal plate to reveal an ecu (transmission?)

All the wiring and pretty much everything under this plate was covered in oil.
Im assuming that from reading other posts/forums that the plug on the underside of the transmission is leaking and wicking the fluid up into the car

Anyone know what the thing in the top right of the picture is (three cables going to it)?

If the ecu is fried is it a fixable part? im handy with electronics so can replace pcb components or would it be easier to replace?

im yet to get under the car to check the plug on the side of the gearbox but will take pictures when i do this.

hopefully ill update more tomorrow.
let me know what you think.
Regards
Dan
​

 

[Julesprivate]

I think you are right about the likely source of the ATF, the connector at the transmission end is a known issue - the nreplacement part from Mercedes is a better design (I believe it should have 2 black o-rings instead of the orange/red ones you probably have now).

If you're lucky then cleaning the unit with electrical cleaner may do it - but if not then it's unlikely to be a home DIY fix as without the wiring diagram it'd be a crap shoot...

Do you have a CEL and hard code P0715? Or is it just a soft code?

 

[MrDan23]

I Had a look at the ecu and the oil doesn't seam to have penetrated in to the box. I'm just hoping it hasn't shorted anything as all the terminals were covered in oil. I've given it a clean and shall replace after i've cleaned the plugs . Haven't had any codes read yet so not sure.

On another note is there a way to check the gearbox oil level with out the dipstick as i dont want to drive it to the garage with out oil and risk further damage?

Cheers
Dan

 

[WillF]

After being flooded in November last year I found the same oily yellow liquid under the front passenger carpet of my C250TD. But it wasn't oil, it was water bringing the colour out of the insulation material on the foot board.

I wonder if your car has been similarly flooded. The insulation doesn't dry out unless the carpets are left out for a long time - mine was still wet 5 months later.

In my case the car only stuck in first gear for a few minutes but the SRS sensor under the seat had to be replaced.

Best of luck with it. I'm considering a CLK myself but there seem to be a number for sale out there with indeterminate transmission problems.

 

[MrDan23]

I always assumed that ATF was red so im not 100% sure what this oily fluid is.
I did try to remove some of it from the foam with kitchen roll and standing on it got most of it out

as you can see its absolutely sodden.

I squeezed my fat head under the car to check the plug on the gearbox and i think its definitely the culprit. The sump pan is covered in ATF as well so im thinking new sump gasket will be needed and plug.

I know the pictures are not the best.

Would it be worth changing the plug, gasket, filter and the sensor plate all in one go?
If so should i order it all off of fleabay or are there better places?

regards
Dan

 

[MrDan23]

Just a quick update.
Got the car on star and the codes cleared at merc world in margate.
Car shifts and drives like a dream, the mechanic told me there was no damage to the transmission which was a relief. But when I was asking him about changing the plug on the gearbox and the sump gasket he said I should leave it until it goes into limp mode again and im better off getting a refurb gearbox which will be about £800. Is he just trying to drum up work or would it be better to get a refurb rather than replacing all the bits that could go wrong?
Regards
Dan