Oily floor pan

[bigasotonuk]

Hi,
As some of you are aware I have for some time going to be fitting OEM Xenons together with Headlight Wash/Wipe, to maintain a legal Xenon fit, electric auto-levelling needs to be fitted, this requires fitting of a ECU, Wiring loom, and front/rear suspension atitude sensors. Fitting of the loom involves me having to remove all the coverings and linings in the front footwells of the car. After removing of the passenger side linings, I noticed there was oil at the foot of the bolted steel plate at the foot of the footwell, which houses the new levelling ECU.
I intially thought this was the oil that is suspended in the refrigerant gas of the A/C as I have been having some issues with it.
I made a phone call and had a chat with a fellow forum member, and think we have identified the problem, and hopefully a cheap solution.
But I thought I would post this and see if the forum think the same as me (and the fellow forum member).
There is a pic, quite poor I,m afraid, the oil had slightly pooled but I had wiped it up before I took the pic, so only the oil on the looms is left (beside the oil soaked up in the soundproofing). The oil is dirty black and about as thin as 3 in 1 oil, with no discernable smell.
Heres the pic, so what do we think it is?

 

[television]

Gearbox connector

 

[bigasotonuk]

So you think the oil is Auto transmission fluid?

 

[Cole@MBS]

As the chat on the phone today Andy, still going connector plug!!

 

[bigasotonuk]

Hi,
Many thanks SAM for your advice and diagnosis yesterday, as I said on the phone there seems to be no oil at the actual sockets of the ECU so I think I can assume the ECU won,t need to be cleaned out. But I think I will open each plug up to clean the connectors up inside.
I,m just surprised regarding this seal as I have not heard of this effecting the C class W202 before, though with the W202 using a 726.6 box I should,nt be surprised.
I got Bobby coming down on Saturday, so I will have a check for oil in his floor pan for him.
What would of been the symptons of this fault? Or as I seemed to of caught the fault before ECU contamination would I have had any? Could oil at the connectors cause shorting out between the cables of the loom (hence my thinking of cleaning the connector plugs of the ECU).

 

[television]

This can happen to any 722,6 box. but one thing does not add up, the oil normally goes between the copper and plastic so it must get up to the multi plug on the ecu, before it can get onto the footwell.
Oil does not give shorts, just take a cup full and put 2 measuring probes in, I have equipment to measure in excess of 100 meg ohms and this gives a zero reading.

Oil is molecules all separated, this is how it works in the running gear in the engine, well the same rules apply to electronics.
We know that odd faults come up when oil has contaminated harnesses and I am still testing out things, but so far not getting any where that makes sense.

I have poured all into a working sky box that contains voltages and signals 1000 times more complex than any car components and the thing still worked perfectly