W203 c220 cdi auto gearbox problem

[WHK71]

I have an 03 W203 C Class C220 CDI Automatic, with only 44 k. It is hanging briefly in 2/3 or 3/4 gears and then jolts forward when changing up. Would anyone have any ideas what the problem might be? I have found a couple of somilar threads but unfortunately no answer. Many thanks

 

[DSM10000]

Get someone, either an MB specialist or an automatic transmission specialist to check the fluid level, also have them check for fluid contamination as the early versions used a Valeo radiator, the gearbox oil cooler runs through the water radiator and it can fail causing coolant to leak into the gearbox. There are other possible causes but rule these out first.

The fluid should have been changed at 37,000 miles, do you know if it was?

 

[BlackC55]

Those symptoms do sound like glycol contamination

 

[WHK71]

Thanks for the advice, the gearbox oil was changed at 32 k due to age, it is going into MB dealer later this week they already ran some checks and said its not an electronic fault. All the levels were perfect but I don't think they have checked for contamination.

 

[markjay]

Search for 'valeo rad' on here - the ATF contamination is a known issue.

 

[WHK71]

The Dealer says the Valeo Rad problem is not the cause any other ideas?

 

[DSM10000]

Yes: Ask him to prove it!

There is a test whereby you take a sample of the transmission fluid and check it for glycol contamination.

At least rule it out properly.

 

[WHK71]

Yes: Ask him to prove it!

There is a test whereby you take a sample of the transmission fluid and check it for glycol contamination.

At least rule it out properly.

The problem turned out to be the transmission control unit which has been replaced and the car is completely sorted.