Thumping

[clyde]

A couple miles from home this evening, I noticed a slight thumping noise that seems to be coming from the right rear of the car but could be anywhere. It's audible from barely moving to at least 45 (didn't go faster). Not sure if it gets louder with speed, but if it does, it doesn't get that much louder.

It seems like it's in time with wheel rotation and I'm not picking up any new vibrations. All the lug nuts are on and they're all at least finger tight. I didn't notice any missing wheel weights or anything odd about or on any of the tires, but I was barely able to see anything.

Nothing much done to the car lately except the front struts. Front brake pads are, um, tired and I ordered a new set the other day, but aren't here yet. Rear brake pads and rotors were 13 months and 13k ago. Car has 40k.

As soon as I get a chance (I hope Saturday morning), I'm going to swap on another set of wheels/tires (inspecting for beating play and anything noticeable on the wheels and tires) then drive a few miles and see what happens.

Outside of a missing weight or something on a tire, what else could it be? Wheel bearing? What else?

[bren]

Rock in the tread?

Does dragging the brake change it at all? What about dragging the ebrake?

Any change if you swerve around?

Tire still has air in it right?

[clyde]

Originally Posted by bren

Rock in the tread?

Does dragging the brake change it at all? What about dragging the ebrake?

Any change if you swerve around?

Tire still has air in it right?

Noise a thump, distinct from the click type noise I've always heard from rocks in tread.

Haven't tried dragging brakes/e brake or swerving. Will try that all tomorrow.

Tires all look properly inflated, but I haven't checked that either. TPMS is a finicky bitch on this car and tends to throw a warning at the slightest thing, but it's been silent.

[Terri Kennedy]

Originally Posted by clyde

It seems like it's in time with wheel rotation and I'm not picking up any new vibrations. All the lug nuts are on and they're all at least finger tight. I didn't notice any missing wheel weights or anything odd about or on any of the tires, but I was barely able to see anything.

Drum parking brake? The insides of rear rotors where the parking brake rubs aren't particularly well-machined, since the rotors are balanced for overall vibration and the parking brake doesn't get used at speed.

Finger tight, eh?

[clyde]

Right rear tire was down to 15psi this morning. Guess there's something in it.

[blee]

Something other than air.

[ZBB]

Back when I had my E39, I had odd vibration and thump, mostly felt/heard at highway speeds.

Mentioned it when the car was in for service a few weeks later, and they couldn't find anything. A couple weeks after that, I was on my way in to work one morning when a tire failed -- a ~1/2 inch strip of tread broke free and was whipping around the inside of the right rear fender -- held on by the radial metal bit (the tire stayed inflated -- it was just the tread that broke free). I pulled over and had to change the tire (in the dark and in a light drizzle...). Once the spare was on, the vibration and noise was gone. I figure the tire was defective (it was nearing end of life, but I still had plenty of tread above the minimum). I ended up replacing just the one tire, and moved the spare (E39s had full-size spares...) to the other side, and put the older tire back in the trunk as the new spare...

[bren]

Originally Posted by clyde

Right rear tire was down to 15psi this morning. Guess there's something in it.

[clyde]

Originally Posted by ZBB

Back when I had my E39, I had odd vibration and thump, mostly felt/heard at highway speeds.

Mentioned it when the car was in for service a few weeks later, and they couldn't find anything. A couple weeks after that, I was on my way in to work one morning when a tire failed -- a ~1/2 inch strip of tread broke free and was whipping around the inside of the right rear fender -- held on by the radial metal bit (the tire stayed inflated -- it was just the tread that broke free). I pulled over and had to change the tire (in the dark and in a light drizzle...). Once the spare was on, the vibration and noise was gone. I figure the tire was defective (it was nearing end of life, but I still had plenty of tread above the minimum). I ended up replacing just the one tire, and moved the spare (E39s had full-size spares...) to the other side, and put the older tire back in the trunk as the new spare...

Delamination is a bad thing. Glad it wasn't worse than that.

When I got home from work, I popped the wheel off and saw a substantial screw.



I was pretty relieved. Was worried it could be a wheel bearing, which is something I'm not sure I could take care of myself by next weekend (when I'm supposed to compete in my first national event in my own car in 10 years).

The only thing I wasn't sure about is whether to repair or replace. It's not close to the sidewall, but I've always been a little squeamish about repairing on an outer tread block. It's okay, but...you know.

Interesting to me is how much life is left on this tire. It's one of the original tires from the FoST. It spent about 18k on the rear and about 4K on the front. I bet
I can get over 10k more on it.

[Terri Kennedy]

Originally Posted by clyde

Interesting to me is how much life is left on this tire. It's one of the original tires from the FoST. It spent about 18k on the rear and about 4K on the front. I bet I can get over 10k more on it.

Aren't all of the treads on the center 3 blocks just gone?