Stripped screws on airbox of my Justa
 

So I've had a few days lately of worse than normal traffic, (bumper to bumper, on the interstate) And then i was following some doofus slowly into a parking lot, they finally moved out of the way so i stepped on it, being in grumpy mood and got into the lot. I then heard a pop/almost backfire sound, not sure if it was me or some other car/motorcycle. ANYWAYS that prompted me to take a look under the hood. I noticed the airbox was loose and 2 of the 4 the screws were stripped out, not gripping when I tried to tighten them. Filter is a bit dirty, but not completely blocked by anything. Did the cheap thing and wrapped the screw threads in electrical tape so they'll at least grip a little bit for now. So what would cause the screws to get stripped out like that? and i assume i'll have to replace the whole airbox now as well? Just about to 80,000 miles on this 2008 car. :P

MINI is not alone with this happening to plastic air intake/filter boxes. I'm a much bigger fan of metal spring clips that reach around to clip a filter lid tight versus using metal screws in plastic. So, if it's possible to do so, you might try filling in the stripped out holes with a bit of epoxy and gently run the screws in before the epoxy has fully set to create new 'threads' in the plastic. Then, remove the screws, wipe any epoxy off of them, and let the assembly and epoxy harden over night for a complete cure before reassembling your air filter box.

I have seen the airbox base strip out on the Cooper S airbox , its the self tapping screws that go into that molded plastic. Over tightening them and taking the intake in and out many times. Also the same for the Cooper S and and the MAF sensor 2 screws after removing and replacing many times. But these were cases of removing and install like 15-20 times in a short period.

thanks. I do still have extended warranty through october, so i'll look into it, if not i'll try the epoxy method when i have a chance, and see how that does.

If you can get to the underside of the threaded part, I'd be tempted to change over to a machine screw and a nut. If the back side is not flat, then possibly pull the airbox out and grind a flat space on the back side for a nut.

Or similarly, drill an oversize hole that fits a small nut, and epoxy that inside the plastic.