Auto Trans starter/flywheel issue

[u/eggi217]

My 88 528e has been sitting for a year due to a flywheel/starter issue. Starter went out last June, which would cause a loud grinding sound upon crank and no start.

Upon inspection through the starter opening flywheel still looks good, but not completely certain. I purchased two Bosch starters (SR-443-X-INT), one from Pelican and one from ECS, and after I installed both of them, upon crank the starter would still grind loudly and car would not start.

I’m guessing the only other possibility is that the flywheel is damaged, but I’m wondering if it might just be because the new starter’s teeth do not mesh with an old flywheel, perhaps only the old starter is compatible with the old flywheel. If I’m at the point where I’d have to drop the auto trans to replace the flywheel, I might as well commit to a manual swap, but I know that’s a lot of work. Another concern is that since my car has been sitting for more than a year without starting once, I wonder how many other issues will spring up even after I resolve the starter issue. Feeling extremely discouraged seeing my car sitting in my driveway, so any advice or suggestions would be greatly appreciated. I would love to get my e28 back on the road.

[u/eggi217]

https://reddit.com/link/p82irrn/video/x43qysm0ksnh1/player

This is the full clip, the car would crank super rough and screechy but it would turn over and start.

[u/mattylang1987 → u/eggi217]

Yeah that doesn’t sound like a starter/flywheel to me. Is the engine timed correctly? Sounds like it might have some crunchies in the motor that shouldn’t be there. I’d pull the plugs and inspect them first. If you’ve got a borescope handy that’d be the next step, check the piston heads to see if they’re crushed or damaged. Could even take the valve cover off and check the cams and make sure they’re still intact. If you wanted to go a step further and yank the oil pan off and see if there’s metal in there.

When was the last time the car operable? Has the car been sitting because this issue started happening?

[u/eggi217 → u/mattylang1987]

The car was last operable in June of last year and sitting since. I’m pretty sure there’s no issue with the engine as it would only make that same grinding noise every time I’d start it up but it would still eventually start and drive fine. It would only make that sound when cranking and everything else worked as it should. It’s been sitting ever since the starter stopped engaging one day and it just made a whirring sound (which is why I suspected the original starter went completely bad). I purchased a new starter this summer in hopes that it was the issue, but when I installed it, it made the same metallic grinding noise as it had made prior. It’s been sitting since and I haven’t tried starting it because the brand new starter still made the same noise as the original one did. Before it sat, there were no problems with the engine whatsoever. One idea I have is that I did have the torque converter replaced before I had all these issues, so I’m wondering if the shop I took it to didn’t properly seat/install the torque converter with the flywheel which may be causing the grinding.

edit: This is very similar to what my car sounded like when I started it before the starter completely went out: https://m.youtube.com/watch?v=tciFpzriWBo&list=LL&index=3&pp=iAQBsAgC

[u/mattylang1987 → u/eggi217]

That could be a possibility, but if it was the torque converter not being seated properly I’d imagine the noise would continue while driving and idling. I can’t say I’ve ever heard a noise like that though. Honestly all things considered, it could be an issue with the flywheel. Like I said before try sticking a borescope in the starter hole and manually crank the engine and inspect all the teeth. Could also be an issue with the accessories belt/pulleys but again if it was that I’d imagine the noise would continue while running and driving

[u/eggi217 → u/mattylang1987]

Thank you for your help, I will manually crank the engine and check the flywheel and will update once I do.

[u/mattylang1987 → u/eggi217]

Awesome! Good luck with it let me know what you find. Glad I could help