I had flooding on my 400E for quite some while and I was puzzled where the water might be coming from.Water showed up at the driver seat foot well. The carpet and the sponge below was soaked full with water after I was driving in the rain, once even the rear foot wells were affected and soaked with water.Leak tests with a garden hose did nothing...meaning water inside was not coming from above. Front window and sunroof were perfectly fine.
I figured out over time that with car parked there were no leaks at all. The leaks must come from below ...driving in rain... but from where. It took a while until I figured out where the problem really was. I was researching about the chassis and inner voids from rear wheel well along the rocker panel ending up in the front of the car ..around the front seat foot wells. So I had some hints but I could not figure it out until I was examining the rear wheel wells more closely. It looked all normal at first sight... nice conservation and I saw the rubber plugs.... removed them and ...oh my... rust.
I was poking holes with my hands around 4 x 4 inches at 2 locations left and 2 at right side, also around the bigger lower plug I had rust. The Mercedes conservation gunk was holding everything in place even though water was leaking in...Finally it dawned to me that these were the ways the water must have taken. Water entered here and filled up the void until water showed up inside underneath the driver seat.... Why on the driver seat only even though I had the same rust holes on the right side too?
The reason was a clogged drain plug just down...close to the areas where I was welding. Fortunately there was no rust inside the cavity. So my hope is that this repair will permanently solve the issue. I have waited to post this thread because I wanted to be 100% sure that I caught all the leaks and after 6 months of dry driving I am 100% certain that this was the problem.
Please find attached pictures of the rust repair on the 400E. I welded new metal in and used rust sealer Por15 to seal the metal as good as I could. I used new rubber plugs all around. So far all is fine.
Best, Martin
I figured out over time that with car parked there were no leaks at all. The leaks must come from below ...driving in rain... but from where. It took a while until I figured out where the problem really was. I was researching about the chassis and inner voids from rear wheel well along the rocker panel ending up in the front of the car ..around the front seat foot wells. So I had some hints but I could not figure it out until I was examining the rear wheel wells more closely. It looked all normal at first sight... nice conservation and I saw the rubber plugs.... removed them and ...oh my... rust.
I was poking holes with my hands around 4 x 4 inches at 2 locations left and 2 at right side, also around the bigger lower plug I had rust. The Mercedes conservation gunk was holding everything in place even though water was leaking in...Finally it dawned to me that these were the ways the water must have taken. Water entered here and filled up the void until water showed up inside underneath the driver seat.... Why on the driver seat only even though I had the same rust holes on the right side too?
The reason was a clogged drain plug just down...close to the areas where I was welding. Fortunately there was no rust inside the cavity. So my hope is that this repair will permanently solve the issue. I have waited to post this thread because I wanted to be 100% sure that I caught all the leaks and after 6 months of dry driving I am 100% certain that this was the problem.
Please find attached pictures of the rust repair on the 400E. I welded new metal in and used rust sealer Por15 to seal the metal as good as I could. I used new rubber plugs all around. So far all is fine.
Best, Martin
