I've been working on my 87 I for far too long and it's time I make some good progress. I've removed the rear subframe (mine was stuck and a big pain to remove), welded in some support brackets found everywhere online, then pulled the engine. My engine has roughly 220k on her and then the oil pressure adapter gave way and oil poured out. So I have no idea how long it was peeing out oil but I was on my way home from work and it's only about three miles away. Still, I figured it's time for a rebuild (hopefully it's rebuildable). Part of my journey is working on the throttle body. There are a few YouTubers that have some good tuts on what they did, and so I'm building off of their knowledge.
What I found out is that there are a couple of different ways that BMW attached the butterfly mechanism springs to the throttle body. I have an early model, so mine was different from the YouTube videos I found, but still easy enough to take apart.
I needed to remove the bearing on the butterfly valve and replace them since it was sticking and 30+ years old. I'm almost certain that it was causing a vacuum leak although I never verified it with a smoke machine. I ordered a replacement bearing a couple of years ago (again, this project has been in the works for a long time) and the replacement parts have two rubber o-rings to help create an air-tight seal.\
I didn't get any pics of me removing the bearings but it was easy enough for me. Instead of trying to cut them out and thus, creating more issues than just not replacing them, I just welded them... Let me explain! I was taught that if a race/bearing is giving you grief, you can apply some heat (via a welder) and it will distort the metal enough to make removing the bearing a very easy process! So ultimately, I just welded them enough to close up the top and then forced them out by running a bold through the length of the body and ramming it out. You can see where my weld on this side bearly spilled over, but doesn't hurt the body at all.
Finally, I started to clean it up in my parts washer (it needs another round or two to fully clean it) in preparation for some Cerakote.
What I found out is that there are a couple of different ways that BMW attached the butterfly mechanism springs to the throttle body. I have an early model, so mine was different from the YouTube videos I found, but still easy enough to take apart.
I needed to remove the bearing on the butterfly valve and replace them since it was sticking and 30+ years old. I'm almost certain that it was causing a vacuum leak although I never verified it with a smoke machine. I ordered a replacement bearing a couple of years ago (again, this project has been in the works for a long time) and the replacement parts have two rubber o-rings to help create an air-tight seal.\
I didn't get any pics of me removing the bearings but it was easy enough for me. Instead of trying to cut them out and thus, creating more issues than just not replacing them, I just welded them... Let me explain! I was taught that if a race/bearing is giving you grief, you can apply some heat (via a welder) and it will distort the metal enough to make removing the bearing a very easy process! So ultimately, I just welded them enough to close up the top and then forced them out by running a bold through the length of the body and ramming it out. You can see where my weld on this side bearly spilled over, but doesn't hurt the body at all.
Finally, I started to clean it up in my parts washer (it needs another round or two to fully clean it) in preparation for some Cerakote.