so after 2 years of dealing with the squeaky top on my z4, i finally got fed up recently and decided to tear sh*t apart. for those of you who don’t know, my top squeaks when my convertible top is stowed (SQUEAK, not rattle, if your top rattles, it is your convertible top lock/latch. There is a service bulletin out that tells you how to file down your latch if it rattles. i can find this easily, if anyone needs it, just PM me)
EDIT (thank you Critter7r on bimmerforums.com):
those of you who were around back in the golden days when z4um.com and GVfB was around, he had a mini write-up regarding how to deal with top squeaks.There's a modification you can do to the current latch for exactly the problem you're having. Modify your current latch to be like the one shown.
Rattle Noise From Stowed Convertible Top
MODEL
E85 Z4 - Up to 6/04
SITUATION
Some customers may complain that they hear a rattling noise coming from the convertible top when it is in the stowed position.
CAUSE
The plastic release lever on the convertible top stowage lock rattles when driving over bumps.
CORRECTION
Remove the convertible top stowage lock by following Repair Instructions 54 31 165.
File the following dimensions from the plastic tongue of the stowage lock:
Dimension A = 11 mm
Dimension B = 6 mm
there were lots of speculation that the squeaks were coming from the convertible lock/latch that sat in the center of the convertible top, mainly stemming from the fact that bmw removed this latch in the later z4 models.
i originally thought my squeak was coming from here as well, so i took this panel off. i applied felt/friction tape EVERYWHERE i could see, and reinstalled the panel. i went for a drive and 3 miles later, the squeak reappeared. i was pissed beyond belief. so i took the panel off, and drove around a week with the panel off because i was going to take a deeper look under the panel.
i found it VERY odd how the squeak wasn't there when the panel was off (yes i drove around with the panel off with the top down looking like a n00b). upon closer inspection, i came to realize where the squeak was REALLY coming from:
(not my pics, i take no credit for these pictures; i only followed them as a guide; a great thanks to pvr on z4-forum.com for these pics):
take a philips head screwdriver and undo the two PLASTIC screws as shown below. be VERY SLOW in doing this, they are plastic screws and get stripped very easily (lord knows why they used plastic screws )
here is a pic of the screws, there are 2 of them. once the screws come out, take needle nose pliers or something of that sort to pull out the two expanding rivets (this is easy, you won't break anything here)
now this is the challenging part, start pulling upwards VERY GENTLY and pushing backwards as well. there are plastic hooks underneath this panel shown below that are VERY fragile. they will break easily if you are clumsy in this step. i wish i could be more descriptive here as to how to remove this panel, but it is very hard without physically being near your car and showing you how to do it. my best advice here is to take your time:
once you get the panel off, please note that you will see 4 springs, a red one and a plain one for each “lever”. the top-release lever is the culprit and it squeaks when driving over road imperfections when the top is down. this is because when the top is stowed, the mechanism on the car is pushed against the top-release lever and it rubs, causing the lever to develop an annoying squeak over time. remove the top two springs, and remove the lever (easy to figure out on your own). I added some felt tape to the two areas on the lever, bent the springs a little so they exerted more force on the lever, and reinstalled everything.
good luck, I take no responsibility if you break anything