Okay guys. Two new sounds cropped up on my car (1991 244) in the last few months, and I was on a 120 mile round trip today to listen closely to them. They are intermittent, so I've had trouble figuring out what they sound like, but today they happened enough for me to listen to them a bit. First, the sounds:

The first one sounds like a "whoo"--much like a person imitating an owl. It generally hoots 2-5 times, and then it may not do anything for miles, or even the rest of the drive. And sometimes it will hoot several times, stop, then hoot a bit more, and stop, then hoot, etc. It is never continuous, but some trips it happens a lot. It seems to be from the mid section or back of the car. I am having a hard time telling, and seldom have a second ear in the car to help me when it happens.

The second sound is more like a howl--high in pitch, although still not loud. it also makes some noise, and stops, then makes some noise and stops. It is less frequent than the other sound, and also never lasts more than a few seconds. I feel like it is coming from the passenger side front tire, but again, another ear is seldom around when it is doing its thing.

I figure these sounds are bearings going out--but this is just a guess, I don't have much experience with that. Both noises are unrelated to the engine speed, which rules out the engine and most of the transmission. The sounds are related to wheel speed--they change with wheel speed, although they do hoot or howl at any speed. I don't think it is in the transmission--it doesn't matter if the tranny is in gear or no clutch in or no. I realize this doesn't rule out the rear end tranny bearings (I have an m46) or maybe some other items, but it also isn't affect by weather i am coasting or powering up a hill, and I would rather expect it to go away in one of those if it was a tranny bearing.

Finally, they seem to be unrelated to each other. They might happen at the same time, or they might not. They often don't. It has also been suggested that it might be the u-joints on the propeller shaft, so I will look at that and see if there is any slop.

As this is my only car, work I do on it will be sporadic... I know I will be super busy tomorrow and may not get to anything until the end of the week, but my first plan is to 1) check the propeller shaft u-joints then 2) see if there is any slop in the passenger side front wheel. But these are just my best guesses--I am not sure I would be able to identify a bearing that is going bad if i were looking at it. If anyone out there has some pointers, I would love to hear 'em. The greenbooks are pretty good, but I wasn't able to find a second about troubleshooting by sounds.

Thanks in advance.

 

center support bearing.

 

+1 on the center support bearing. Just to confirm, when you have the sound while traveling at speed, place it into neutral for a second or two to see if the sound changes. If no change, then I think that would be the culprit. You need to take the driveshaft off to fix it. While it is off, check out and grease the u-joints.

 

I had one come in and I swear it sounded Like a ghost.

 

Thanks, I'll get on that next time I can get the car off the ground, and report back. I appreciate the feedback.

Act--I have done that, and yes there is no change, so I'll work on getting that part, and getting it in.