Bought a low-mileage 2001 E320 last month. Nice car, but the sunroof leaks. Seal looks a little weak and the cassette (pan) is rusted through (drains are probably plugged, leading to the rusted out cassette). Previous owner squirted silicone sealant everywhere to try to stem the tide. I'd like to replace the seal first and see if that stops the leaks. How do you replace the seal?

If I have to replace the whole cassette, how is that done? Is there someone in ATL that can do these projects for me at a reasonable price? When I took the car to my MB dealer, they took a look at the messed up cassette and suggested I hire a body shop to replace the cassette. The body shop says it is a mechanical repair and I should have the dealer do it! That sort of leaves it up to me. I am pretty handy, but have never done this particular repair...

 

This gasket is not 100% sealant (from factory), every day comes water inside the roof, but the drainer works perfect comming the water outside the car. you would clean the drains firs and see what happens

Anyway you can replase the gasket. but in 15yr i never replase this in any mercedes :s try cleaning the drainers!

Fabio Daniel

 

Fabio,

That is how it should work. But the pan (cassette) is totally rusted out in front so if water leaks past the seal, it can leak through the pan. If the car is parked on a slight incline, nose down, it will leak at the front of the headliner.

 

Arthur in the 'Look Here First' Sticky at the top check the DIY - Sunroof Repair with has a link to the procedure. There is also a DIY on Headliner removal but most of that doesn't apply.

 

Wow! nevr seen a rusted cassete in this car! but is possible. Comes water inside all the time. Hope you can solve this, i'm sure you can fix it without change all the pan

Fabio Daniel

 

I doubt a new seal will stop all the water from getting in to the pan. We can park the car with the nose pointing down, to keep water off the front edge of the pan (cassette). But that is not a long-term solution.


I think I will have to drop the headliner and either repair the rusted out pan or replace it. I don't want to do this, but I don't see any alternatives...

 

@Arthur Gardner: When you have a leak, water will get under the rear seats via the C-pillar! (the base of the headliner is made of polyester wich is waterproof) The battery, PSE pump and wiring under the rear seat could all get wet! Remove the rear seat to check this, wipe it all dry if needed and tape-up your sunroof until you can get it sorted!

Ayways I've been tackling this same problem all day today! I had drops of water coming from the sun visor hinges on the drivers-side when snow on the roof of the car was melting last winter, so I taped the roof up.

This week I ordered the outside gasket that's between the glass panel and the metal roof. This gasket just looks like a small felt lining on the outside but is actually half an inch wide on the inside. This gasket sits between the roof and the glass panel, preventing a freeflow of water into the cassette. The water that gets in the cassette is drained through 4 drainhoses. (2 through the A-pillars and 2 through the C-pillars)

Replacing the outside gasket is a real b!tch... (read: a large project)

The entire headliner needs to be removed from the car.

Then the entire sunroof cassette needs to be unbolted and dropped, I let it hang on the front seat headrests in the upper position.

Only then you can reach the torx-screws holding 3 strips that press the gasket against the edge of the roof!



I already noticed tell-tale mineral deposits on the inside of the headliner.
See pic:


The strip holding the gasket to the roof was rusting at the same spot. You can clearly see the rust on the old gasket here:


With the new gasket pressed in and screwed down, the roof clearly opens and closes slower, the motor has to work harder indicating the seal is better!

Here's the number:


(I only have these 4 cellphone pics, my parents have my SLR with them on a trip to Bonaire...)

It was getting dark so I mounted the interior lights, sunvisors and rear parktronic display with cableties and left the headliner out. I'll drive it thru a carwash later this week and check for leaks...