Potential ATF leak

[VenomX]

The other day I saw a rainbow like mark on the ground infront of my car after it had rained, thought nothing of it.


Just today I looked under the car, and the sump which holds ATF appears to feel very greasy and have a lot of dark brown substance on it, here is a picture.



Is the best thing to do get a dispstick and check the levels ? If they are low I will take it to a mechanic as I am not willing to do work on it myself due to clearance issues.
Car is a 2002 W203 C240 with 34K miles on the clock.

 

[Petrol Pete]

I remember hearing on the radio some woman, when asked by her little kids what the rainbows were on the road she told them it was where a fairy had been run over !!

You have a 22 year old car with 34K on it ! fair play . Has the transmission ever been serviced ? I ask because at that age the seal around the TCU plug or even the gearbox rubber gasket itself could be leaking a bit.

If you have the opportunity to park with a sheet of card under the car it might help pinpoint they type of oil, but ultimately it needs to go up in the air with the lower covers off for inspection.

 

[Bellow]

Just today I looked under the car, and the sump which holds ATF appears to feel very greasy and have a lot of dark brown substance on it, here is a picture.

That could be any oil from nearer the front of the car being blown back in the airstream as the car is driven. Need to pinpoint oil type and leak point. Checking levels in all reservoirs wouldn't hurt.

 

[VenomX]

That could be any oil from nearer the front of the car being blown back in the airstream as the car is driven. Need to pinpoint oil type and leak point. Checking levels in all reservoirs wouldn't hurt.

Thanks. Defo not fuel or coolant as it is greasy and dark brown - with barely any smell. It appears to be coming from around where the TCU plug is as suggested above. ( the white spot I saw this morning on the ground, was directly under the TCU plug area )
Brake fluid levels are fine, and the car has not reported any issues with engine oil levels but I will double check that later.

 

[Bellow]

Thanks. Defo not fuel or coolant as it is greasy and dark brown - with barely any smell. It appears to be coming from around where the TCU plug is as suggested above. ( the white spot I saw this morning on the ground, was directly under the TCU plug area )
Brake fluid levels are fine, and the car has not reported any issues with engine oil levels but I will double check that later.

Looking a lot like you have it nailed - check the PAS (assuming it's hydraulic) though. Its fluid is very similar to (if not actual) ATF.

 

[VenomX]

I will try to replace the TCU plug myself, is it as straightforward as YouTube videos show ?
This here...