My E30’s Window Motor Broke So I Had to Get Clever

2022-05-21 14:21:31 By : Mr. Jerry Deng

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Leaving a window down overnight in your 1990s BMW project car isn’t an option when you live in New York City.

A few months back I bought a 1991 BMW 318i sedan to use as my autocross and track car for the 2022 season. While it’s not perfect, it drives way better than I deserve. Now that it’s legal for the road, I’m driving it a lot more. I put over 200 miles on the working (!) odometer this past weekend, and the car drove beautifully the entire time. But it’s not a project car if something doesn't break.

I spent Saturday helping out friends swap an engine on their Miata race car, and that meant several trips to the local auto parts store. Having four doors means I can comfortably carry four people, so we all hopped into the E30 to gather the missing parts we needed. The weather was perfect so I immediately put all the power windows down. All went well until we got to the parking lot and found out the driver’s-side rear window wouldn’t go back up. Not good.

If I had a garage to park this car, a broken window motor wouldn’t be a particularly big deal. I could leave it down and drive around in nice weather until I sourced a replacement motor. But I don’t have the luxury of a garage—I park this car on the streets of New York City, where I live, every night. Leaving it down overnight would leave the cabin open to any number of NYC regulars, like rain, insects, and rodents. Even though this car's body has suffered three decades of rust-filled winters, its interior is actually pretty nice, so I didn’t want to ruin it. Plus, it would make the car about 45 times easier to steal.

I had to get clever.

I took a break from working on the Miata to figure out how to get the window back up without a new motor. Taking off an E30’s door card is an incredibly easy affair, all you have to do is unplug the window switch, unscrew the elbow rest, and pop a bunch of plastic clips along the card’s edges. Peel back the factory plastic sound-deadening, and you have access to the window mechanism. Unfortunately BMW switched up its window motor design on later E30s, meaning this one doesn’t have a manual backup feature. So I couldn’t simply wind up the window manually. If this were an earlier model, I'd be able to stick an allen key into the motor and spin it up by hand. Of course it wouldn't be that easy.

It took about 30 seconds of poking around to learn the window is attached to the motor rail with just two bolts. So I unscrewed those, allowing the window to move freely along its tracks. The only thing I had left to do was figure out how to prop it up within the door. My friend’s driveway wasn’t exactly a treasure-trove of spare parts, so I looked around in the hopes I’d find something that would fit. Luckily I had a snow scraper like this one in my trunk that fit perfectly inside the door, long enough for me to be able to wedge it under the window so the glass would stay up. Problem solved!

I drove another 100 miles with that scraper piece in place, and it’s held the window up just fine so far. I don’t want to keep it there forever, as I’m sure it’ll fail eventually and send the now free-moving window crashing into the door. Alas, BMW no longer makes the motor in question. The only way to buy one is used on eBay for over $300, which I can’t justify. If there’s a way I can get the current motor to spin into the up position and lock it there, that could be a more permanent solution. I’m sure I’ll figure something out.

On the plus side, I finally got around to changing the oil. Motul hooked me up with some quality oil that can handle the high temps I plan to subject it to, while FCP Euro supplied an OEM-quality Mahle filter, which fit perfectly. Because the engine takes up so little space, doing routine maintenance is a breeze. There’s even enough space to add an OEM water pump-driven fan to support the electric unit installed by the previous owner. That’ll ensure the car doesn’t overheat in especially slow stop-and-go traffic.

I still have to upgrade the brakes and source a good set of wheels and tires if I want to take this car to the track. So I’ll tackle those items next... as long as nothing else breaks. Stay tuned.