Looking at a 635, any common issues I need to be aware of?

[MSB123]

Heading to look at an 87 635csi this weekend, seller states it is running well. No other real info.
I do have a fair share of experience on e39/38, but have never touched e24. Looking to shore up my knowledge before heading to chat with the seller.
Want this to be something I fully restore, so things like failed suspension are a given and will be replaced.

[1986series6]

Here's one guide I could find, I'm sure a search will bring up others.
Euro=good, US= lousy, I don't think so. The Euro will rust more than
the US version, but both are prone to rust if not cared for.

https://www.hemmings.com/blog/articl...se-bmw-635-csi

Get the best sorted for the money. Restoring a basket case should be avoided at all costs because it will.

Here's another forum for info.

https://bigcoupe.com/phpBB3/index.php

[DesktopDave]

E24-specific parts can be difficult, but much of the car is shared with other models. The later cars (like the one you're checking out, are easier). If you're really familiar with working on the later E38 & E39, you'll be shocked at how simple an E24 is! It's practically the same car as the E39 minus the electronics (the V8/recirc steering models anyhow). Check the build sheet or run the VIN if you get a chance. I'll keep my fingers crossed for you! Post some pics!

The E24 came with very few options, so there's not really a lot that goes wrong. I prefer manuals with LSD & sports seats, but you can't be picky. There are some really fun options for upholstery, including different colors of trim & leather. I'm still hoping to find a buffalo leather sport interior at some point in my life.

Rust is a significant issue depending on the climate, but it's relatively easy to find & deal with. Be sure the hydraulic brake booster is in good working shape, it's unique to the later E24. They're actually kinda cool, very reliable, but they can wear out seals over time. The tell-tale is an ATF leak under the master brake cylinder. Be sure to test the heat. The E24 basically has two totally separate systems for the heater & A/C, including two separate fans. Oddly, the center dash vents are only for fresh air. Don't expect them to be controlled by the HVAC temperature dial. Both the heater control valves and the temperature control dial can fail, it's rare but expensive when it happens.

There are some really rare parts that you might think are easy to find...but they're not easy. I'd be very particular about the dashboard. Also the taillights & housings, especially the chrome-plated bezel/surround. It's a zinc casting that's quite prone to corrosion. Those are currently NLA and quite hard to find in good shape. Front door seals too. Front spoilers & foglights are especially hard to find in good shape. The memory seat controller is prone to malfunction, difficult to rebuild, also worth a mint. A complete toolkit or first-aid kit is a definite plus. I think Bert can set you up with reproduction parts, he's incredibly thorough.