1999 Toyota 4Runner squeals

On my 1999 4Runner(4WD if that matters), I get an annoying squealing sound from the front-right. I occurs at almost any speed and goes away when I press the gas slightly. The sound does not change with engine rpm, A/C usage or tranny usage. My timing belt/water pump/drive belts were recently changed and sound was there before. I thought about a brake wear sensor, but after a full brake job the sound is still there. A mechanic said he traced it to the front-right wheel bearing, but after $600 the sound came back. Any ideas?

When my '87 Toyota pickup squealed it was a loose alternator belt. It was hard to tighten: I had to make a wedge from a scrap of 2×4 cut obliquely, jam it in with a rubber mallet. It also only happened at start, went away as I sped up.

When my brake pads wore thin they made a scraping sound, not a squeal. If you can record your sound and post it here that may help.

The tire rubbing up against the wheel-well, or some detached piece of it, can make a squeal.

Is the noise speed dependant? Does it follow wheel rotation? Do you hear it outside the car when driving? Does it go away at some point when you sway to the right or left? Does the car roll freely?

Thanks for the ideas. Regarding an alternator belt, I had the noise before I had the timing and all drive belts replaced. I figured it would have been fixed or changed afterwards.
Secondly, the noise does not change with turns or bumps. Car rolls perfectly. I get the noise when going straight and I hit 30mph or faster and driving easily, then it goes away if I slightly accelerate. Change in engine rpm does not affect the rate of sound. I thought if the U-Joints, but they’ve been greased. Thanks again, Dan.

Did the mechanic check the drum brakes? Rust can grow around the edge of the drum and make contact inside the channel of the backing plate. Here’s a trick I learned a long time ago… drive the car when its raining because water acts as a lubricant and can quiet things down.

Thanks Corollaguy, I’ll check the drums.

Sometime you can use a spray bottle to spray water on a belt to test if a belt is squealing. If the sound goes away when you spray an accessory belt with water, replace or adjust the belt.

Does this sound change when driving, when you shift into neutral and coast?

I would take it back to the mechanic that put on the new belts.

There could be a bad pulley or bearing in one of the items that the serpentine belt operates.
This should not be that hard to find, but sometimes these noises can fool the best mechanic.


Tomorrow I’m taking the car back to the mechanic and who replaced the timing belt, drive belts and the wheel bearing. I’m leaving the car with him for a couple days so he can drive it leisurely and investigate.


After the mechanic had my 4Runner for 4 days (he said so he could spend time driving it, but from the leftover evidence, he also used it to pickup auto parts for his other repairs), he could not find anything causing the metallic scraping. He said he rechecked the brakes, engine belts and pulleys, alternator, U-Joints, undercarriage brackets, etc., so at this point I’ll drive it until the noise is constant or something breaks. Again, the noise is elusive as it only shows up between 30-40mph and goes away if I press the gas. Weird.