Water in trunk...not your typical cause?

[E30andy]

Hey guys! I’m sidetracked with this other problem while waiting for my subframe parts to get back from the powder coat.

I have been getting water in my trunk. Replaced ALL the stuff people recommend and hasn’t helped. Pulled my bumper and found all these factory holes in the rear apron/sail panel that are not present on my 89 parts car.

I wonder if the previous owner of the 88ix that I’m working on (pics attached) didn’t plug these holes when he did the metal to plastic bumper swap and they are the cause of the water in the trunk? Do all metal bumper cars have these holes in the rear apron? Seems kinda odd that they arent present on my 89ix.

Thanks!

[uturn]

Those holes are from the diving board bumper trim pieces. I use foam tape on the inside to seal them. A decent RTV with a hard backing piece should solve your problem.

[E30andy]

Thanks uturn! I ordered some rubber plugs off eBay for a cleaner repair.

[monty23psk]

check your seam sealer where the quarter panels meet the rear tail panel. with age they will crack and allow water in. Also, the grommet for the wiring for the rear side marker lights can also crack and allow wager into the trunk.

[packratbimmer]

Make sure the plastic/rubber flap vents that go under the bumper on the sides are sealed properly - I usually clean them well and silicone around the oval. Let me know if you need a pic oaf what I am talking about.

[E30andy]

Make sure the plastic/rubber flap vents that go under the bumper on the sides are sealed properly - I usually clean them well and silicone around the oval. Let me know if you need a pic oaf what I am talking about.

So where do you apply the silicone?

[nando]

I would be careful with silicone. Some types are acidic - they will end up *causing* rust instead of preventing it. Probably better to use a rubber plug instead. I'd hit up the hardware store and see what you can find.

[packratbimmer]

Pop the big rectangle out of the oval hole. Clean everything well. Dry well. There is a gasket around it. Seal with your favorite sealer. I'm thinking most automotive grade silicone products are fairly acid free due to use on cooling systems, but by all means watch for acidity issues.

[moatilliatta]

You can get new gaskets from BMW, please don't silicone.

[mjweimer]

Trunk vent gaskets = 64 22 1 922 280

https://www.fcpeuro.com/products/bmw...ng-64221922280


The fuel filler door locking rod trim can also leak if someone has removed it in the past. BMW uses some butyl sealant around the inside perimeter of the rubber boot where is presses against the body (deep inside the quarter).

Between these two parts:

[E30andy]

Thanks fellas! So the more you research the more possbile sources for trunk leaks! Will order gaskets for the trunk vent (thanks packetratbimmer!) and also the fuel filler door locking trim (thanks mjweimer!)