After about 15 to 30 minutes of driving, the car starts making a sort of high pitched whine. It starts soft and gets louder, then continues steadily for about 10 to 20 minutes. Then it just stops. We notice nothing else in terms of steering or power or other sounds or smells. There seems to be no pattern in terms of weather conditions or drive time. It does stop when we apply the brakes, but will start right up when we stop applying the brakes. It doesn’t seem to matter what speed we’re traveling - it happens when we’re doing 65 on the highway or 25 on a city street. We’re worried that something is going to blowup.
My first suspect would be your brakes.
The car’s brake pads have audible wear indicators built into them, and when you start to hear the screeching noise, this means that very soon the pads will have no friction material left, and the metal-to-metal situation that will result, will lead to damage to the brake system as well as very long stopping distances.
The audible wear indicators will make noise while you are driving, and will stop making their annoying screech when you apply the brake–just as you have observed. When you no longer hear the wear indicators at all, then your brakes are totally gone, so please don’t interpret a cessation of this noise to be a good thing. It is actually a very bad thing.
Take the vehicle TODAY to a competent mechanic, and have him pull all 4 wheels in order to check the brakes thoroughly. If you do indeed need new brake pads, you should also have the brake fluid changed, as this is supposed to be done every 3 years/30k miles. If you are told that the brake rotors are not in good shape, pay a few dollars more for new rotors, rather than having them machined. Machined rotors frequently cause problems that can be avoided if you spend a bit more for new rotors.
I suggest that you avoid chain places like Midas, Meineke, Monro, Sears, Pep Boys, Brakes Plus, etc. You will be more likely to get good workmanship and fair pricing at an independent mechanic’s shop.
If you wind up in an accident as a result of worn-out brakes, you could be facing criminal charges if examination of your vehicle indicates that you were operating it with faulty equipment, so this is not something that you can afford to defer.
Take the car to the mechanic TODAY.
If he determines that your brakes are not at fault, he should be able to figure out what other condition might be causing the noise.
While I agree mostly with VDC, I suspect that you may actually have a sticking caliper. I think that because it takes 15 to 30 minutes of driving for the noise to start, which is enough time for the rotor to heat up.
Again, like above, get it to a mechanic today.
Thanks to you both. Actually, we have had 4 mechanics drive it and they heard nothing. The wheels were removed, tires rotated, balance, and alligned. The brakes are ok- “plenty of life left in them.” Hub assembly ok. The word “caliper” wasn’t mentioned…I’ll follow up with that. Our mechanic is well known to us and excellent.
Any other suggestions? Recommendations?
Just paid $300+ for replacing brake pads and rotors in the rear plus cleaning hubs on front. The sound is gone and it’s running great. Then again, it was running great when the noise was a problem. Thanks for getting us to focus on the brakes. We’re glad to have this problem solved so we can enjoy driving this car again.
PS Our mechanic is solid. He’s done everything to our cars for over 20 years. When he retires, we’ll really struggle. It will be like losing our doctor or our dentist. These three are people we trust absolutely and they’re really hard to replace.