Tackling knock sensors

[mobius]

Good to hear man. If you want to hear some battle stories here's mine for the weekend. I was trying to drain all the coolant out and even after soaking it a ton and being careful I snapped the head off my block coolant plug. It was rusted but not that bad I thought. There's only one solution now to remove the engine. Then I'll have to drill and tap it worst case but I'm hoping I can weld onto what's left and get er out. Yes it sounds like a nightmare but it gives me a good excuse to do alot of work in that area and check the tranny. She'll be new by the time I'm done.... The end of summer lol.

[1996 328ti]

YIKES!

[BlackBMWs]

Steven, prolly too late now, but the first time I pull an alternator from a M42 or M44, I use my grinder to take a little contact surface off of the alternator faces. Not so much where it flops around, but really, just a top layer. This helps it get back into place way more easily and I don't have to break out a dead blow to convince it back in place.

I do the same when I am fitting a replacement in place. Sooo much easier.

[1996 328ti]

Originally Posted by BlackBMWs

Steven, prolly too late now, but the first time I pull an alternator from a M42 or M44, I use my grinder to take a little contact surface off of the alternator faces. Not so much where it flops around, but really, just a top layer. This helps it get back into place way more easily and I don't have to break out a dead blow to convince it back in place.

I do the same when I am fitting a replacement in place. Sooo much easier.

I thought of that but a thin layer of grease really worked well.

[mobius]

BlackBMWs that's exactly what I did to mine. It was just enough to make it easier to do. Otherwise like you I would have been brute forcing it onto place .

[1996 328ti]

I put the car back together.
After it warms up the idle goes down and starts to stumble until stalls as before.

CEL: Emission (lambda) control

Previously I had Knock control regulation

Seems to have something to do when warmed up.
Could still be the rear knock sensor that I can't get to.

[skimmer]

Wow over 9,000 posts I'd figure you would have a answer for all ti issues.
Hang in there I know you will solve this problem

[1996 328ti]

9000 posts. I've been here a long time.

Seems heat related. Once the car is warm the idle goes to crap.

[96318ticali]

I just finished replacing my head gasket last weekend, and upon starting the car everything seemed fine. Took it for a drive, after about 5miles CEL comes on. I scan it and it's the knock sensor (bank1) and MAF out of range. I clear CEL drive to work (10 mi.) no CEL. Restart to go home within 5 seconds CEL back on. I check, same 2 issues, clear it drive home no CEL. Every other start after clearing CEL it comes back on but only when I first start the car, not while driving. The idle is rough at first then smooths out. When stopping for red lights/ stop signs, idle will swing between 400-850 rpm. My BMW mechanic buddy used his BMW diagnostics and only issue was knock sensor. I know knock sensor will retard the timing but will it cause idle issues? Thanks for any help/ insight you can give. Also is Beck Arnley a good brand for sensor?

[1996 328ti]

Originally Posted by 96318ticali

I just finished replacing my head gasket last weekend, and upon starting the car everything seemed fine. Took it for a drive, after about 5miles CEL comes on. I scan it and it's the knock sensor (bank1) and MAF out of range. I clear CEL drive to work (10 mi.) no CEL. Restart to go home within 5 seconds CEL back on. I check, same 2 issues, clear it drive home no CEL. Every other start after clearing CEL it comes back on but only when I first start the car, not while driving. The idle is rough at first then smooths out. When stopping for red lights/ stop signs, idle will swing between 400-850 rpm. My BMW mechanic buddy used his BMW diagnostics and only issue was knock sensor. I know knock sensor will retard the timing but will it cause idle issues? Thanks for any help/ insight you can give. Also is Beck Arnley a good brand for sensor?

That's my issue until it stalls.
It's going to go on a flat bed to a shop this time around.

[96318ticali]

Best of luck. Mine doesn't stall (yet), I really don't feel like pulling the intake again as there's not a central wiring loom disconnect on the 97 so it's a pita.

[bazar01]

Originally Posted by 1996 328ti

Stuck. I managed to pry it out. Can't seem to get it to line up back it its mount. I'll get back into it next weekend. Going away for a few days.

The alternator mount has a steel threaded hex insert on the mounting tab.
What I do is squeeze them out with a c-clamp to widen the mount opening.
Once you do this, the alternator drops into place without a fight.
I'll see if I can snap a picture.

[mobius]

That's basically what I did on one that was being a struggle for my friend. I used two knipex locking pliers. My own the inserts were so worn out it didn't matter.

[bazar01]

Here are the hex inserts I was talking about.
Use a c-clamp to push them out and simplify alternator reinstall into the mount.

[1996 328ti]

Throwing in the towel. Car is being towed next week to a shop.
I gave the owner a run down of everything I did and surprisingly he didn't dismiss it. I told him I'm trying to learn to be a DIYer but also know when to stop. And it's time to stop. So I think he appreciated that.

I'll have him replace the rear knock sensor since I already bought it.
He is suspecting that it's something with the cooling under the lower intake manifold since idle is OK until warmed up. I am not doubting that the other knock sensor is also bad.