Author Topic: Sunroof leaks into trunk (Read 5815 times)

DirtyD · « **on:** September 13, 2012, 03:29:48 PM »

I have an e30 '91 318iS and my sunroof drain on the driver side leaks right into the trunk. I noticed at first that the drain tube had come off and was hanging down. I put it back on but that didn't fix anything. Last time it rained i noticed water trails coming from wherever the drain tube comes from. Looks about impossible to fix but that's just me. Anyone have any ideas?

DesktopDave · « **Reply #1 on:** September 13, 2012, 05:13:01 PM »

Could be that the upper tube plugged & rusted off. Hopefully not...get yourself about 6' of coaxial cable and snake it in there to check if it's clear.

I've also seen a lot of leaks on the trunk seal itself, right under the hinges. There's a weld there that tends to rust - water pools in the corners of the trunk pocket, seeps along the rusty seam & under the trunk seal, then down the spring mount and into the trunk.

You'd likely have to pull the rear of the headliner and the c-pillar off to really get a good look. It's been too long since I pulled one apart, but I believe the rear & c-pillar fabric is retained by the rear window rubber seal. It's a heck of a job.

keflaman · « **Reply #2 on:** September 13, 2012, 06:16:58 PM »

Another area to check is the grommets that hold the molding on the rear quarter windows. I replace them as a matter of preventive maintenance. Numbers 18, 19, and 20: http://bmwfans.info/parts/catalog/E30/2-doors/USA/318is-M42/LHD/M/1990/july/browse/vehicle_trim/exterior_trim/

DirtyD · « **Reply #3 on:** September 13, 2012, 06:19:01 PM »

There is a little bit of rust on part of the seal but not right under the hinges. Next time it rains I will do a better inspection. It still seems that it is coming from the abyss up there near the sunroof.

Ironically, the passenger side trunk pocket is the one that is totally rusted out. Might need to mount my battery somewhere else soon haha!

Quote from: keflaman;115895

Another area to check is the grommets that hold the molding on the rear quarter windows. I replace them as a matter of preventive maintenance. Numbers 18, 19, and 20: http://bmwfans.info/parts/catalog/E30/2-doors/USA/318is-M42/LHD/M/1990/july/browse/vehicle_trim/exterior_trim/

Is there an easy way to check those grommets?

DesktopDave · « **Reply #4 on:** September 13, 2012, 07:08:54 PM »

I found that poking a hole through the original drains cleared my problem. All the e30s I've checked had them plugged at the factory with seam sealant.

I still get a good bit of condensation in the trunk, having those holes cleared out really helps.

DirtyD · « **Reply #5 on:** September 13, 2012, 07:20:16 PM »

Will I need to take the headliner, etc, off to do that?

DesktopDave · « **Reply #6 on:** September 13, 2012, 08:53:24 PM »

Oh no, I was talking about the trunk pockets. If you look at them from underneath the car, you'll see one on each side. They're just punched in the bottom of the sheetmetal. I'll take some pics wen it gets light outside again since I'm not being very clear about this.

DirtyD · « **Reply #7 on:** September 13, 2012, 09:46:03 PM »

Alright, that makes sense. I'll take a look in the morning

edit: I saw what you mentioned, easy fix. Thanks for the help!

diamonddonbmw · « **Reply #8 on:** December 09, 2012, 08:27:44 PM »

Can you please post a picture of the outside area please? I've been trying to locate them on my car, but am not sure what to look for! Thank you

keflaman · « **Reply #9 on:** December 09, 2012, 09:33:21 PM »

In the bottom of the spare tire well and rear quarter pockets there are drain holes that are often plugged by sealant applied at the factory. The right rear quarter pocket typically suffers worse due to a combo of water and battery fumes.

To get to the drain holes properly, you most likely need to remove the trunk lining and lift it out of the pockets to find the drains. Here's my car and you can see where capillary action drew moisture/salt under the sealant and rusted along the body seams. I drew green circles where to look. It's a good idea to inspect the battery vent tube for correct installation, kinks and obstructions.

The only indication I had of damage was some bubbling of the sealant along the seams. Like a little kid with a scab, I started picking at it until I had the huge, festering wounds you now see. :rolleyes: