Squealing / grinding noise at start up.

[oceancrest67]

I have a 4th Gen 2003 Toyota 4Runner-V6-Limited with 198,000 miles on it.

I take good care of it because I believe routine maintenance leads to a longer lasting vehicle. It is my daily driver and I do clock mileage with a long commute to and from work.

I am now noticing a more consistent squealing almost grinding noise upon start up and while in operation. At first I thought the air compressor clutch / pulley might be going but I am hearing this noise with the air off. I had the water pump replaced about 2 month ago as well as the serpentine belt.

What else could it be? Anyone else out there with a similar experience?

Thanks.

 

[BlackWorksInc]

Do you go off-roading a lot? I am going to guess one of the bearings is going bad. Did you check and see if the tensioner is failing?

 

[oceancrest67]

I do not go off roading. Mileage on my 4Runner is mostly highway. I would agree that a bearing might be going bad. I am pretty certain it is not the air compressor clutch pulley. I am pretty certain that it is not the water pump...that was replaced 2 months ago. I am pretty certain it is not the starter motor...usually those let out an initial squeal at start up.

 

[jimithing]

Why couldn't it still be the A/C compressor pulley? That pulley is spinning whether you're running the A/C or not. Like BlackWorks, it sounds to me like a bearing is going bad somewhere. Go pull the belt off the tracks to relieve stress on the pulleys and then turn each of them 1 at a time until you find the bad one.