Rust areas? 1989 300E
 

I have a 89 300e showing some signs of rust near the C pillar. Adjacent to the rear window frame/rubber to body area. Seems the drainage was poor or simple plugged up to collect grime and moisture.

Anyone with similar issues or where else do I need to start looking for other cancer spots.

Thanks.

Maybe the sunroof drains got clogged? There are two that run back from the sunroof, straight back and down the c-pillar. W124 is fairly good chassis for rust issues. But if you live in the rust belt, anything is fair game. Get a flashlight and check out the underside of the car thoroughly.....the wheel arches are also a common rusting point.

Check trunk lid seam, under door seals and especially the car jack cavities on the rocker panel. I would remove the covers on these and spray the interior with Krown T-40 (or similar product). Rust can start here and eat into the rocker and underpanel. You generally won't notice it until it has progressed past the point of easy repair.

I also coated the inner rims of the wheel arches with a rubberized rockerguard paint, which really helped prevent rust there. Could use POR-15 as well.

Good luck!