240D Cancer Rust problem - PeachParts Mercedes-Benz Forum

steeleygreg · #1 04-04-2011, 10:32 PM

I recently purchased an 82 240D Sedan which had light body rust. I did all the standard mechanical things to make sure the engine was sound first. Now, I’m turning my attention to rust and how to stop it.

I’ve noticed over the years that all 240D seem to rust in the fender/quarter panel area. I may not be using this term correctly, so please excuse me if I am. The area is just in front of the driver’s door and aft of the front tire and that’s what I’m defining to be the quarter panel / fender. Checking the front sunroof drains, I’ve noticed that the drains exit at a location in front of the driver/passenger top door hinge. Trying to figure out how water would drain out of the car from this point, I noticed a small hole at the bottom of the quarter panel / fender, right above the frame and front jack point.

Investigation through a dealer stated that this hole was put in by design.and is meant as a drain. Since all 240D’s that I’ve seen have this inherant issue with rusty quarter panels, it’s pretty obvious that this drain is not working to well and is trapping moisture resulting in rust over the years. So I’d like re-route the drain and would like some ideas as to where would be a good exit point of the car.

The fenders on the car will have to come off, for these quarter panel areas are pretty rusted up. New metal will need to be welded in to provide the necessary strength to the fender. If the drain is not re-located or re-routed outside the body so as to drain correctly, then I’ll have the same problem 5 years down the road and have to do this all over again.

I plan to user POR 15 on the backside of the fender but a drain scupper will need to be fabricated. Any ideas ?

Any help would be appreciated.

Thanks
Greg

JohnM. · #2 04-04-2011, 10:36 PM

Greg,

The problem isn't so much with the routing/locating of the drain tube, it's that nobody ever cleans the tubes out. IIRC you are supposed to check/clear sunroof drain tubes every 2 years or so along with the usual routine maintenance. But no one ever does it along with lubricating the lock cylinders, the door hinges, throttle linkages, etc.

I would first make sure the drain tube is free and clear of leaves/debris (use a fish tape), and then pour water down it until it drains smoothly. If you are unable to get it to drain properly, then you can look at re-routing the tube.

steeleygreg · #3 04-04-2011, 11:06 PM

Thank you JohnM. I used a nylon weeder line which was fished down the front sunroof drain holes. I was checking for debris, leaves and anything else which could be stuck. This is how I located the exit point and the drain into the quarter panel. Is there a drain tube also in the quarter panel ?

JohnM. · #4 04-04-2011, 11:09 PM

I don't know the intimate details of the W123, but Mercedes drains should always end up on the ground under the car, someway or another (they are Germans after all). There must be another drain hole in the chassis to deal with water run-off from the sunroof. Maybe another more educated member can chime in with those details.

Stretch · #5 04-05-2011, 02:52 AM

Hi Greg,

Welcome to the forum - I see you are on post #2!

The front sunroof drains are designed to empty in the area you describe. To access them you can see a bit by removing the plastic panel behind the front wheels:-

More information about other drains at the front of the car here:-

http://www.peachparts.com/shopforum/showthread.php?t=286079

The rear sunroof drains on a W123 come out behind the rear trim at window height behind the rear doors on a saloon.

To gain proper access to the rust on the front of the car you are better off removing the front wings - have a look here as an example:-

http://www.peachparts.com/shopforum/showthread.php?t=286062