Why is my car squealing?

This morning, just before I arrived at work, my car started making a loud squealing noise. It started very suddenly, and seemed to come from the back of the car. When I stopped the car (but the engine was still running), the noise stopped, then came back when I started moving again. It’s constant in pitch, but has a EEEeeeEEEeeeEEE that increases in frequency as the car moves faster. No noticeable difference in the behavior of the car.

I got out and looked around & under the car, but nothing jumped out at me. I smelled a faint but definite odor of burning plastic, but that may have just been from the parking garage I was in.

Earlier in the morning I had put the parking brake on for a few minutes, because I was parked on a steep hill, but the sound didn’t start until I had driven a good 10 miles. I can’t remember the last time I used the parking brake though.

Any ideas? It’s a 2001 Grand Caravan. If it keeps up, I’ll bring it to the shop, but just wondering if this is something obvious the car gurus here would know about.

You might need new brake pads in the back.
At least on disk brakes, there is a small piece of metal that gets closer and closer to the rotor as the brake pads wear. When they get down low enough, the metal touches the rotor. When you move, it rubs and screeches.

I am not a mechanic, but that’s my guess.

The disc brake thing is what I would check first. If it’s not that it sounds like a wheel bearing.

I’ve found you can feel a temperature rise on an affected wheel if a brake pad/disc is binding. Compare the difference between wheels.

Thanks for the help. In the past I’ve always observed that brake squeal starts quiet and gets progressively louder over a few days. This literally went from inaudible to louder than a normal speaking voice in a few seconds, and stayed that way.

I’m guessing the parking brake is seldom used (like most every other automatic equipped car in America). I would venture a guess that when you used the e-brake, the rear brakes on one or both sides remained stuck on due to rust in the cables or the mechanism. The odor you smell is burnt brake pad. What happens when you come to a stop and let off the brake? If the car doesn’t start rolling forward, or moves slower than normal, then thats your problem.

Just FYI, a lot of Grand Caravans have drum brakes.

Assuming discs, one possibility that you may be able to fix yourself is that something may be stuck in the brakes. Most disc brakes have a dust shield behind them, which is a thin metal thing shaped a little like a dinner plate to protect the rotor from debris. Sometimes it acts more like a trap than a shield and a rock or something can get between that and the brakes and squeal like crazy. You may be able to lay down and look between the shield and the brakes and see if there is anything in there and be able to remove it.

Followup: When I got back to the car after work, I applied and released the parking brake 2 times before driving out, just in case something was stuck there. Drove home, took girls to skating, bought beer, all with no problems - no squealing from the brakes, no binding, if I came to a stop and then released the brake pedal, the car rolled straight forward as expected. So I’m chalking this one up to the auto gods.

I have an 05 Grand Caravan and my front brakes squeal after a short drive and only when the wheel is straight and the brakes are released. I replaced my front pads and rotors back in June before driving on a 3000 mile summer vacation. When the squeal starts I can barely touch the brakes and it will go away. Maybe I purchased bad pads or maybe bearings need packed? The squeal is the same EEEeeeEEEeee high pitched and follows the rotation of the wheel. Any ideas??? Thanks.

I have had a belt squeal like that, particularly when it is cold. Not sure which one, but it generally stopped once it warmed up. It just needed a little adjusting. Very cheap fix.