Fixing coupe trunk latch (56k beware)

[StarReaver]

Just recently I found out that I should be able to open the hatch of my M coupe from the outside without the key. All this time I thought it was just the way BMW made it, but it was just broken, like on many other coupe owners. So I present this DIY-guide to fixing that damn trunk that won't open when you press the button.

First off, you have to remove two screws located inside the trunk lid, right where the little handgrip is.


Next is the hardest part (took my brother and I about an hour to figure this out). You have to pull the black covering off the trunk lid to expose the latch mechanism. It's really tough and your fingers might get sore. Much easier with plastic trim pulling tools (available at Harbor Freight for $6), which I did not have at the time of this write-up.


Just to make sure, the plastic part and the fake leather part are one piece, so make sure you know what you're pulling off.


The reason it's hard is because the plastic connecters have these "barbs" that hook in and don't want to come out. Note that I busted the one in the bottom right corner.



Now that the cover is out of your way, you should see this.


If you examine carefully, you will see two brass rods bent 90 degrees at the tips and a white connector clip.


To simplify, the tips of the brass rods should be inside the clip like this.


Here's another pic to show the out-of-place rod (and my brother's crotch).


With mine, the white clip was broken, so one of the rods wouldn't stay inside. We had to fasten them together somehow to prevent the rod from falling out.


We tried electrical tape: it works, but doesn't last because of the stress exerted from the moving parts.


It seemed like a useless effort, but it helped me realize that there were no pivot points. I decided to use epoxy putty to just hold everything in place.


I applied some to both rod tips, just in case the other one decided to break.


The finished result: it's ugly as sin, but it'll be covered up anyway. More importantly, it's strong as steel; meaning it won't snap like the plastic did.


-edit-
Apparently the epoxy didn't work out as well as I had hoped. But I found out the problem: I didn't really wait long enough for it to set because I was too eager to try it out. I took off the broken chunks and zip-tied the rods to the plastic clip. Then I applied a smaller piece of epoxy so that it only connected the zip ties with the clip. Apparently the rod moves slightly when the latch is pushed, and that caused sufficient stress to break the first epoxy piece at a weak point.

cliffnotes: Got impatient, cracked epoxy, but re-applied different and it's fine.



Once everything is complete, put the pieces back together and you should be set! No more malfunctioning latches!

[///MDex]

Nice work, write up, pics, and use of epoxy

[Coupe Dejour]

Great pics, it's been covered many times but your pics are excellent.

You should also point out the installed check valve in the waher line that you can see in the pics. It fixed the leaky washer wiper. I did that also while I was in there. Then when I had the panel off, I replaced the cheap carpet on the panel with leather, ala LeatherZ fix.

I made a bent piece of metal with two holes in it to keep the rod in there, then z clipped it in place for good.

It's a great time for 3 mods in one, so you don't pull that cover off many times.

[IslandS62]

Good writeup. I did the same early on, but used some wire and zip ties to secure everthing instead of epoxy. I've never had great luck with glues...except for JB Weld.

[jacus]

great writeup.
i don't know if i get this right. does it mean that you should be able to open the hatch from inside of your car?

[StarReaver]

Thanks for all the positive comments, guys! I'll be updating this every so often, so be sure to check back whenever you get the chance.

///MDex: Epoxy is like the Force. It has a light side, a dark side, and it holds the Universe together...

Coupe Dejour: That's a good tip! I'll go and update it once I gather a bit more info on the wiper. 3 mods at once, huh? That's what I call economic!

IslandS52: Ahh! You jinxed me! The epoxy cracked, so I went back and zip-tied, the re-applied epoxy in a different way so it doesn't recieve any stress.

jacus: Sorry for the confusion. After doing this, you should be able to open the trunk from the outside by just pressing the latch button, rather than having to use the key everytime. If your latch has always been working, then you don't have to worry about anything- yet.

[Blacksport350]

OMG, I'm amazed that you got back out of there! The one time I tried that, I almost had to call the fire department!

Nice DIY!

[pelotudo]

I know this is a super old, but I just wanted to make sure that the interior panel can be removed while the hatch is still closed. I've got the same issue with mine and going to be crawling back to remove the screws and pop off the panel to try to manually pop the hatch if so.

[StarReaver]

I've never tried to remove that panel when the hatch was closed, so I am not sure. My guess is that you can't because the edges of the black plastic trim are wedged against the inside off the hatch when it is closed. Have you tried opening the hatch with the key?

Also, it has been almost 10 years since I fixed my latch and made this thread, and my epoxy/zip tie fix is still working.

[pelotudo]

I've tried with the key multiple times but with no avail.

When I push the button or turn the key to the left I hear what sounds like the actuator moving inside but it wont pop. I cannot turn the key to the right. Any suggestions?