Rubbing/scraping noise when warm

[Devin]

The driver side of my engine bay is making a cyclical rubbing or scraping noise. Think of if you were rubbing sandpaper on wood. It's fairly loud and it only appears to occur when the car is warmed up. I took the wheel off, nothing is rubbing. Brake calipers are tight, bearings are rock solid, the CV boots are still sealed and all of the supension and steering stuff doesn't move no matter how hard I yank on it. This leads me to believe it is transmission. I haven't had the fill nut off yet. I haven't noticed any puddles below the car, but there is oil on the bottom of the transmission.

One thing of note. When the tranny shop inspected my transmission, they put the case halves together with RTV. There was at one point some concern the RTV could get gunked up in the oil passageways.

Anyway, does that sound at all like transmission noise?

 

[JRA2000TL]

When does it make the noise? At idle? Only when moving, normal driving, accelerating, braking only? How about only when the clutch is pushed in? That can make a rubbing/whining noise when your TOB is bad. My 95 does this as that's what it needs.

 

[Devin]

Only noticable with the accelerator pressed. Definitely not present when clutch-in.

 

[jelloslug]

Does the noise change with RPMs or vehicle speed?

 

[Devin]

Yes, I believe with vehicle speed. It is almost inaudible at highway speeds, but it could just be constant at that speed and blending in with the wind, road and engine noise.

It is very noticeable 15-30MPH on side streets.

 

[jelloslug]

put it on jack stands and see if you can reproduce the noise.

 

[rubydist]

throwout bearing loose? have you adjusted the clutch cable lately?

 

[Devin]

Don't know and no.

I may or may not have put green loctite on the TOB sleeve when I installed it... that wouldn't cause this would it? We had to pound it on really hard when we installed it.

 

[Devin]

Okay, got it running warm again, it started making the noise at low RPMs. I parked it and saw some vapor/smoke (very, very light) coming out from under the drivers side engine compartment.

I put it up on stands and there was no noise. What I did notice is that in first at idle, clutch out and no gas the driver side wheel just barely moved. I got it up to third with partial throttle and the right wheel was spinning and the left one was not.

Stuck caliper or shot Diff. Are those my choices?

 

[intimdatr]

Stuck Caliper. An Open diff in the air is only going to spin one wheel, Correct?

 

[jelloslug]

Stuck Caliper. An Open diff in the air is only going to spin one wheel, Correct?

yep..

 

[Devin]

yep..

Orly? Well if only one wheel is supposed to spin maybe that is a false positive.

I will take the brakes off and recompress the cylinder and rebleed to see what happens.

 

[jelloslug]

Orly? Well if only one wheel is supposed to spin maybe that is a false positive.

I will take the brakes off and recompress the cylinder and rebleed to see what happens.

you might have a rock between the dust shield and the rotor.

 

[Devin]

Just went on a slow test drive. Didn't get above 35 MPH, braked lightly the entire time. Around the 3 mile mark the sound appeared. The passenger side brake rotor was hot to the touch and so was the driver side. The driver side caliper was slightly warmer, but I could hold my hand on it.

So anyway nothing definitive. Any ideas on some more tests to do?

On maybe a related note, there is a small bit of play on my passenger-front wheel when it was up in the air, so I think I need to replace the bearing.

 

[Devin]

So I took the brake pads off and they have a very thin lip that goes from non-existent on the trailing edge to 3 mm or so on the leading edge. I'm thinking that this could be the noise I am hearing, as it happens possibly once the brakes heat up. I wonder if the caliper bracket is not in the right spot?

 

[Devin]

I feel like I'm spamming my own thread

So after a nice long test drive (and some 6K+ on-ramp goodness) I reproduced the sound after filing down the pads. I did not see anything contacting or that could contact the wheel, brake or spindle.

I'm at a loss. I have one more thing though. I have no idea if this is normal, but I lifted the drivers side up (the side making the noise) after the drive and spun the wheel in neutral. It barely spun, and stopped immediately after I let go. I lifted up the passenger side (after dropping the driver side) and spun the wheel and it was probably twice as easy, and it kept spinning for a second or two after I released it. Is that normal?

 

[itwonder]

So after a nice long test drive (and some 6K+ on-ramp goodness) I reproduced the sound after filing down the pads. I did not see anything contacting or that could contact the wheel, brake or spindle.

I'm at a loss. I have one more thing though. I have no idea if this is normal, but I lifted the drivers side up (the side making the noise) after the drive and spun the wheel in neutral. It barely spun, and stopped immediately after I let go. I lifted up the passenger side (after dropping the driver side) and spun the wheel and it was probably twice as easy, and it kept spinning for a second or two after I released it. Is that normal?

It still sounds like a dragging caliper on the driver's side. Is wear even on the inner and outer pad? Take the caliper off and then spin the wheel - see if there is a difference. Do the caliper pins have fresh grease and are they free of corrosion?

 

[Devin]

It still sounds like a dragging caliper on the driver's side. Is wear even on the inner and outer pad? Take the caliper off and then spin the wheel - see if there is a difference. Do the caliper pins have fresh grease and are they free of corrosion?

I just changed the pins but I neglected to grease them. The old ones definitely did not have a good coating of grease on them.

I'll take my calipers off next week(this weekend I am out for my anniversary. Don't think the WAF would be in my favor on that).

I had another thought I will be chasing down as well. The wife noted yesterday that the car stinks when I rolled up. I noticed that today that there was a heavy exhaust smell when I got out of the car, and this is not a normal thing. When I jack it up to look at the calipers I am going to inspect the manifolds and the catback. This could explain a "swinging" sensation I've had recently when slowing down.

 

[Devin]

I'm leaning on the caliper pin theory. I took my pads off again and they wore at an angle. I'm getting my second rotor turned and will replace the pads, get new pins and grease them this time. *crossing* fingers.

 

[jelloslug]

If they were worn at an angle it's the pins and/or the bracket.