Firstfives.org

Hello,

Having lots of squeeking, scraping noise, for lack of better description coming from crank shaft pully or vibration damper I think, well after engine warms up, not cold. Localized it by spraying lubricant between pully and damper. Goes away for a while but comes back. Wondering also if related to rough idle startups(engine shakes) for about 10 seconds, not related to choke as much as maybe the damper maybe?

Anybody have any suggestions or confirmations helpful as always.

Thanks you!

Are you sure the water pump isn't seized up?

Yes, it seems the noise goes away after I spray lubricant between the pully and damper. Water pump is only 2 yrs old.

What kind of lubricant are you spraying on there? Try to use something more substantial than WD40.

I've heard of dampeners separating, not on BMWs, but I suppose it's possible. So crawl under there and see if it feels tight. Work a big screwdriver in there and try to wiggle it. Look for wobble while it's idling. A bit of a PITA for troubleshooting, but try pulling the belts, or at least loosen them as much as you can to try to determine location. Also look closely, there might be something stuck behind it rubbing, even a twig or something.

It's involved with warm up, that's all in the FI system and timing, there is no choke and unlike newer cars, no crank sensor so nothing that would be affected by it that way.

Got under car as suggested and there was no wobble in damper while running, and not loose when wedged with big screwdriver. From underneath is louder sounds like it is internal in engine, maybe the oil pump?

Hopefully the attach drop box link will let you hear the birds chirping lol.

"C:\Users\ivan9\Dropbox\E12 New Engine noise.mp4"

Spray used was blaster max synthetic.

Trying the link of the noise again...

https://www.dropbox.com/s/wmvkmybyw0uu6 ... e.mp4?dl=0

Sure sounds like the alternator or water pump, possibly worn belts or pulleys. Have you tried isolating the sound by listening with a stethoscope or screwdriver?

Yes put a stethoscope on the the alternator. It could be the bearing in there that is failing. Or maybe a poor aftermarket water pump? Be careful with the stethoscope....don't get it caught in any moving parts.

Yes in fact did use a stethoscope and big screwdriver while under there yesterday and still could not isolate it. Do agree maybe it is just belts or pulleys but not the alternator or water pump. Suspect pulley the most as subsides when sprayed with lube.

Then is the crank pulley solidly bolted to the crank hub?

Yes, did not budge at all when wedged with big screwdriver or grabbed with both hands to see if any movement.

Intriguing. Does it go away at higher rpm? Or does the pitch increase?

Haven't noticed it getting louder at higher rpm, just as the engine warms up and then steady at idle.

Its an odd sound. I've had a strange noise on my 77 the whole time I've had the car. Tried everything. Mine is more of a chirping at idle that goes away ay higher RPM. Another thing I tried was one at a time removing the Vbelts and see if it stops. Even the water pump belt, I just didn't let it run long obviously . It was a while ago and I don't really remember the outcome But the car still does it so I guess it didn't narrow it down.