Help me figure out my bearing squeal 1980 240D
 

So over the last week I have started hearing a quick chirp of what sounded like a bearing when i was making sharp turns. So i was thinking that a front wheel bearing might be going out.

However, this morning i started to hear the chirp when i would accelerate from a stop at a red light. It was just a short second of chirping.

Then i was able to get the chirping to happen when in neutral (manual transmission) and just throttling the engine a little. This will induce the chirping.

Could this be a belt that is fooling me? The belts are all in good shape...

Can someone help me. I can do any suggested tests to further help the diagnosis.

Remove the belts to check. Best way to eliminate the possibility.

Mike,

Are you saying to replace the belts, or actually just remove them. If i remove them, i will not be able to drive long, because i wont be powering the water pump and dont want to overheat.

I was going off this part of your post. You wouldn't want to actually drive since you wouldn't have power steering or assisted power brakes.

You might need to manually shut down the engine doing this test depending on the condition of your vacuum system.

Understood. I will keep checking to see what i can find. I will see if i can hold out until i redo the whole front end steering.

Probably a loose or shot vee belt. Tests are simple. With engine off see if you can move the alternator fan blades by hand. You should not be able to.

More important is the belt for the power steering may have issues.Simply because you heard the chirp on sharp corners when the power steering pump was taking a higher Loading.

If you take a bar of household soap and rub it on the exposed vee of the belt with the engine off. If the problem stops you have the culprit. Although the treatment of the belt will not last.

I had the "bird chirping" under the hood on my 300sd that was driving me crazy. I shot a quick blast of wd40 on the alternator bearing, behind the pulley/fan. That quieted it down for a couple months.

I'll report you to animal cruelty if you do that again!

Thanks Strech, i needed a good laugh after today.

Here is a video that i took with the belts still on, and the car in the driveway. i think it sounds more like a bearing, so i might just start squirting wd40 around, to see if anything specific quiets down.

20160511_174543_zps6vzyn3yw.mp4 Video by arcticathlon | Photobucket

http://i292.photobucket.com/albums/m...ps6vzyn3yw.jpg

Definitely belt. Try adjust the PS pump first :)

Sorry - I always have trouble seeing photo bucket videos - so I can't check for myself - however

If NZScott says it is the belt I'd believe him and have a look at that first

(He's a reliable chap!)

Nice to know I have some "street cred" lol

I had a similar problem once, but it turned out to be a bent alternator bracket. Lucky for me I knew a very kind guy via work at the time who had the keys to a engineering shop :)

After watching the video, it does sound more like belt squeal than alternator bearing.

Also, be very careful where you're spraying WD40, you can easily make the belt squeal worse!

Well if the guy in the corner with the basin hair cut and the 70s flares gives you street cred then - well...

...I'll say no more!

So i think it is belts for sure, and here is what i was able to do this morning before i left for my commute.

I was hearing a faint squeal that was continuous, but very quiet. this was at regular idle. I could not make it squeal just like in the video by throttling, so this is was all i could go by. I sprayed some Belt squeal stuff on the AC compressor belt and it went away instantly. My AC does not work, and i might as well just cut the belt off, until i am ready to fix my AC properly.

However, when driving to work, it started to squeal again when i am applying throttle. All the belts are of unknown age, and I think i really just need to replace all of them (except the AC belt). It could be it is another belt that is making the video squeal and the AC belt was also slightly squealing.

thanks for all your help so far.

Dan