Strange squealing noise comes & goes

I have an 03' 2.7L 4wd Tacoma with 160k on it. For the past year I have heard a squealing noise that comes and goes while driving. It usually only last for 30 seconds to 2 minutes on average. Sometimes it last a little longer. Often I will hear it for a couple days and then I might not hear it again for a few days, a few weeks, or even a few months. I often notice it when driving on the highway after I back off the gas just slightly, but other times when driving normally as well. I havent noticed that temperature has any effect on it. I replaced the water pump and all of the belts a year and half ago and greased all of the fittings underneath the truck 2 or 3 times. Any1 had the same symptoms or know what this is? Also are there any grease fittings on the wheels for the wheel bearings, if so I could not find them. Thanks for any info.

 

Likely one of the drive-belt idler pulleys. You can replace the entire pulley, or just the bearing. Common problem.

 

Agreed. My wife's 96 with the 2.7 had the same issue. I don't think it was a terribly expensive job, but we hadn't met so I can't be sure. Worth fixing though

 

you can notice when the squealing is coming from the belts or pulleys. as you rev the engine, the pitch will change with it. pay close attention to when it happens. is it when youre going a certain speed, only when youre moving (not when youre stopped), etc etc.

 

If the belts are good, seeing as you recently replaced them, it is likely a pulley/tensioner causing it.