A puzzler for all you experts. What starts squealing at about 20 mph, quiets above about 2500 rpms (in any gear), gets much louder when you let off the gas (also in any gear), and stops altogether after about an hour of driving or so? it sounds like its coming from under the hood, or at least in front of the cab somewhere. The vehicle is a 2000 Toyota Tacoma and any advice would be greatly appreciated! drop me a line with any ideas please: email@example.com
I give up what is the answer?
I would suspect a pulley bearing or belt starting to go.
Remove the serpentine belt and rotate each pulley by hand while listening and feeling for any grinding or scratching noises.
I recently had noise from my 2001 Tocoma. It was the power steering. Remove ps cap while engine running, listen to hear if the squeal increases in volume. I pulled some fluid out of the ps reservoil and replaced it with new fluid. Drive vehicle and repeat. I did this two times since I was only removing part of the fluid each time. Squeal is now gone.I realize there remains possible bearing damage in ps, but it’s sounds good now. Lucas power steering fluid is a good replacement fluid if it’s a ps issue.
I have a 2004 Tacoma with a very similair problem. My happens when I let off the gas and the rpms get around 1200. It comes and goes, when the temp. outside is warm it doesn’t happen. All the belts have been replaced and a/c bearings and it still happens. I very interested in the resolution to your problem.
2003 Tacoma PreRunner
The solution is to simply grease the 5 or so fittings on the U joints along the drive shaft. I was going nuts with this until I came across this solution on the Net – tried it and it worked!!
I had this exact problem, only in the winter for 2+ years. It would squeal when cold only while moving. Not when idling and reving, so not a belt. It would squeal when moving, even if I shift into neutral. Very difficult to diagnose. The crappy Toyota dealer hear blamed it on the power steering pump, but that was absolutely not the problem with mine. The grease fittings were all it took. I’m not sure why they apparently were never greased across repeated oil changes at Toyota!!