Having read the posts on the problem on W211's regarding the coolant entering and ruining the autobox's on these models, I went to find the makers name on the radiator on my '03 E320 CDI.
The only name that I could see was 'Behr'. I was therefore wondering if I have escaped the problem and have...
Just spent 108 quids to carry out a glycol test, just to ensure that my E500 does not have that awful issue.
The test came back ok, no issue. But a preventative action is to replace it, not sure if it is worth it though.
I was quoted about 1000 to replace the radiator, a bit pricey I think...