Inconsistent Squealing/Grinding Noise - Please Help

Hey guys - so here's the story. Drove up to the local mountain resorts after Christmas. En route, in stop-and-go traffic, my wife and I heard a "ping-clang" sound, followed immediately by squealing/grinding at the wheels. We immediately pulled over into a turnout. I inspected under the car and found no problems and no warning lights on the dash popped up. We called Subaru for a flatbed tow back down the mountain. When getting dropped off at the local dealership, while the car was backing down off the flatbed, the squealing was present briefly, and then stopped. Out of curiosity, I started up the car and drove it around the block without any problems. The manager there suggested that sometimes pebbles get lodged into the brakes and could interfere with mechanical function.

 

So we proceeded to drive back up the mountain as the car was symptom free. Drove around all week in freezing weather, through sluch and ice without any problems.

 

Then just today, was driving back down the mountain at around 45-50 MPH, heard the same noise, follwed by the same sound. Pulled over again into a turnout and called for a flatbed tow. About 20-30 minutes later, I decided to test the car and found the noise to be gone. Was able to drive all the way home (about 100 miles) at freeway speeds without any problems.

 

So, does anyone have any thoughts as to what the problem is? I'm afraid if I go to the dealer then they won't be able to reproduce the sound. Is this truly a "pebble", winter-related incident? Help! Thanks!

Things can get caught b/t the brake pad and rotor...I once had a dried leaf caught in there and it made a nasty "nails on a chalkboard" noise.

 

Your problem sounds different though because it is intermittent.

 

Have you noticed any loss of braking power?

Things can get caught b/t the brake pad and rotor...I once had a dried leaf caught in there and it made a nasty "nails on a chalkboard" noise.

 

Your problem sounds different though because it is intermittent.

 

Have you noticed any loss of braking power?

 

No loss of braking power - stops on a dime.

 

Are the brakes/rotors really that susceptible to debris?

Did the noise happen as you were taking a turn?

No loss of braking power - stops on a dime.

 

Are the brakes/rotors really that susceptible to debris?

 

They really aren't. My leaf incident was very unusual according to everyone I ever asked and it happened about 5 years ago with my old car.

Did the noise happen as you were taking a turn?

The 1st time I was driving straight in stop-and-go traffic. The 2nd time it happened, yes, I was coming off of a turn but a very mild bend.

 

Is there a possibility that some brake components are loose?

Similar thing happened to me about one year ago. I was just driving down the highway at first I though the noise was coming from the car in front of me. I pulled over and checked everything as best as I could. Found nothing out of the ordinary, and the noise has never come back since.

Hey guys - so here's the story. Drove up to the local mountain resorts after Christmas. En route, in stop-and-go traffic, my wife and I heard a "ping-clang" sound, followed immediately by squealing/grinding at the wheels. We immediately pulled over into a turnout. I inspected under the car and found no problems and no warning lights on the dash popped up. We called Subaru for a flatbed tow back down the mountain. When getting dropped off at the local dealership, while the car was backing down off the flatbed, the squealing was present briefly, and then stopped. Out of curiosity, I started up the car and drove it around the block without any problems. The manager there suggested that sometimes pebbles get lodged into the brakes and could interfere with mechanical function.

 

So we proceeded to drive back up the mountain as the car was symptom free. Drove around all week in freezing weather, through sluch and ice without any problems.

 

Then just today, was driving back down the mountain at around 45-50 MPH, heard the same noise, follwed by the same sound. Pulled over again into a turnout and called for a flatbed tow. About 20-30 minutes later, I decided to test the car and found the noise to be gone. Was able to drive all the way home (about 100 miles) at freeway speeds without any problems.

 

So, does anyone have any thoughts as to what the problem is? I'm afraid if I go to the dealer then they won't be able to reproduce the sound. Is this truly a "pebble", winter-related incident? Help! Thanks!

 

 

I hope you get it sorted out. I bet the towing company either loves you or hates you...depending on who's paying.

I got a similar noise when I went to Chicago to get protuned by P&L in November. It happened twice shortly after getting off the highway. The first time I was taking a right-hand turn and all of the sudden I heard a clanging metal sound, but thought it was another car. It almost sounded like someone was dragging a muffler and it was bouncing around on the ground. When I realized it was my car it stopped and started making a screeching metal-on-metal grinding sound until I stopped to get some food before heading over to the shop. After coming back to my car I looked around to see if I could see something wrong and didn't see anything obvious. I started moving again and it was gone. It came back again as I was making a left-hand turn just before getting to P&L. I asked them if they had time to do a quick inspection for me while it was in there and they ended up not finding anything either. The noise hasn't happened since, and I still don't know what it was exactly.

I got a similar noise when I went to Chicago to get protuned by P&L in November. It happened twice shortly after getting off the highway. The first time I was taking a right-hand turn and all of the sudden I heard a clanging metal sound, but thought it was another car. It almost sounded like someone was dragging a muffler and it was bouncing around on the ground. When I realized it was my car it stopped and started making a screeching metal-on-metal grinding sound until I stopped to get some food before heading over to the shop. After coming back to my car I looked around to see if I could see something wrong and didn't see anything obvious. I started moving again and it was gone. It came back again as I was making a left-hand turn just before getting to P&L. I asked them if they had time to do a quick inspection for me while it was in there and they ended up not finding anything either. The noise hasn't happened since, and I still don't know what it was exactly.

 

I had that exact same thing happen to me. I thought the bolts on my CBE had come loose and it was dragging on the ground. A visual inspection showed everything was where it should be. It was at the time my clutch was going and I haven't heard it since.

That's kind of unnerving that several of our cars have had the same incident, yet nobody seems to know what caused it. I just don't want to get stranded somewhere - on a 2-lane mountain highway in the snow is pretty bad. I guess I'll mention it when I take the car in for its next service.

 

Anybody else have any input?

My stock up pipe heat shield is loose it makes that noise but randomly. It's cheaper to go after market that fix it. Apprently the powertrain and extended warranties don't cover the heatshields.

Update: car is in to the dealer, but without them being able to reproduce the noise, I don't think it'll do much good.

I've had this happen one time on a gravel road and what I did was pull over, then back up a bit, go forward a bit, etc. Finally, whatever it was must have fallen out. It was a screech more than a squeal.

Update: the dealer couldn't find any problems. Still been driving fine. Hopefully it was just a rock and has since dislodged.

I had the same thing happen about a year ago. Leaving work I hear this "ping", then "grind/squeal" sound, with NO brakes applied, no gas applied, just rolling. I was in my lot at work still, so I pulled into an open area/parking spot to inspect. Nothing at all to be seen under the car, no sign otherwise of any problem.

 

I get back in the car and just as I start to slightly back up out of the parking spot I hear another "scraaaape, PING" sound, and I could swear I heard/felt something bounce off the inside of my drivers front wheel well, then....nothing. I drove around that lot in circles, forward, backward for like 20 min. People must have thought I was nuts. HAD to be a rock or something caught between the rotor/brakes somewhere. Nothing ever since from it.

I had the same thing happen about a year ago. Leaving work I hear this "ping", then "grind/squeal" sound, with NO brakes applied, no gas applied, just rolling. I was in my lot at work still, so I pulled into an open area/parking spot to inspect. Nothing at all to be seen under the car, no sign otherwise of any problem.

Wow - that sounds EXACTLY like what happened to me. So weird, isn't it?

Episode #3 today. The "ping" followed by some grinding sound happened again when gently braking in a parking lot following a weekend in the snow without problems. Pulled into a parking stall, went in to a store for a few minutes, came back out to the car and the noise was gone. Drove the rest of the way home without any problems. Each time this has happened, the problem resolved on its own and the incident involved snow/slush.

 

Is it possible that some ice/snow/slush is getting worked up into the drivetrain, and gets knocked around when I brake, then takes a little while to clear itself out?

Same thing happened to me about 8 months ago. Was driving on the highway and I started hearing some nasty squealing/ grinding noise. At first I wasnt sure if it was my car but after careful listening, it was. Occurred a few more times within a month and I brought it to my friends shop which couldn't find anything wrong. They said it might be the heat shield but I haven't had any more occurrences since then. I also brought it to the dealer and of course, no sound replication.

I thought it was only my car but it seems like other people are having it too. I have had no issues with my car so maybe it was just a rock or something stuck in there.

They said it might be the heat shield but I haven't had any more occurrences since then.

 

I'm not familiar with the heat shield. Is it a piece that can be replaced easily? Or at least focus the dealer's attention there to see if there are any problems? What does it come into contact with on the car?

This "ping, rrrrrrrrr" sound...Is there a noticable feel in the brake pedal when it happens? Mine does that sometimes too, like when I'm backing out of a parking spot or something. My grandma's 97 cadillac catera also does it very consistently, and my old 1995 Infiniti J30 did it too. I always figured it had something to do with the ABS system initializing or something. Cause it was exactly the same feel on the GM, Infiniti, and Subaru...can't be a coincidence.

I'm not familiar with the heat shield. Is it a piece that can be replaced easily? Or at least focus the dealer's attention there to see if there are any problems? What does it come into contact with on the car?

 

I can't say for sure it was the brake heat shield but they sorta bent it in the case it was the problem (rubbing). I do not think it is ever supposed to come in contact with anything, just shield components from the heat.

 

The dealer could not find any issues when I brought it to their attention so unless they can replicate the sound when they drive it, I do not know how much help they will be.

 

It seems that everyone here who had this problem, the problem went away after a while. It was a scary sound for me the first time I heard it. Thought my breaks were locked or something.

Episode #3 today. The "ping" followed by some grinding sound happened again when gently braking in a parking lot following a weekend in the snow without problems. Pulled into a parking stall, went in to a store for a few minutes, came back out to the car and the noise was gone. Drove the rest of the way home without any problems. Each time this has happened, the problem resolved on its own and the incident involved snow/slush.

 

Is it possible that some ice/snow/slush is getting worked up into the drivetrain, and gets knocked around when I brake, then takes a little while to clear itself out?

 

It sounds like traction grit (pebbles, small bed rock) stuck in the brakes. It was gone when you pulled out of the parking space because you went into reverse, pulling the debris the other way so it could fall out.

 

It is not the heat shield(s), which also is a problem on many Subaru models. They will shake/come in contact with exhaust at certain rpms, making it sound like you drive a '78 Grenada. It sounds like rattling, but not the awful screeching caused by rocks in the brakes.

 

Your slush theory is half right, it is helping the rocks get in there when they are normally thrown clear/away by the tire.

Does the issue go away if the vehicle is parked and idling or parked and turned off?

 

If it goes away because you are turning the vehicle off, then I'd definately look for a loose heat shield. The heat shield may only be rattling once warmed up and perhaps it takes a particular bump in the road/turn of the wheel/etc to get the noise started.

all of these symptoms,are exactly like the ones my car had when the wheel bearing was replaced @23,000 miles....Good news is it's doing it again...maybe it will take me 3 times to get it diagnosed by the dealer.

 

Search for hub bearing noise/failure....there's alot of them.