Colchicine

2000 Toyota Tacoma 2.7 L with squeaky belt drive and vibration

This truck (with around 50,000 miles) has a baffling condition, a persistent and obnoxious squeak that is present but only when the vehicle is in motion. The squeak does not happen when the motor is revved in Park, but only when the vehicle is in motion, and my foot is taken slightly off the gas pedal and when coasting to a stop. The squeak ceases at around 1100 RPMs. The squeak is very loud and noticeable even over a reasonably loud radio.

I have only novice mechanical skills. The first thing I thought were the belts need replacing. Since I did not suspect any other problems I did not take the opportunity to test for play in each of the pulleys while I had all of the belts off. After that I noticed that the idler pulley for the air conditioner had a very noticeable wobble at idle speed, and none of the other pulleys, including the idler pulley for the power steering pump did not. After removing the air-conditioner idler pulley, I had reason to believe the bearings may have started to go bad and replaced it. The new idler pulley has the same wobble and I would imagine it is normal.

The squeak is still present and may have even gotten worse after replacing the pulley. Belt dressing will make it squeak even worse, although running the AC seems to have no effect. Something that may or may not be related to this is a vibration while in gear and at a complete stop. I remember when I got the truck it ran so smoothly at a stoplight I had to check the tachometer to see if it was still running! Mostly I can feel the vibration all of the time (running the AC or defrost has no affect), but there have been instances where the truck is running smoothly for 30 seconds only to have the vibration take over the entire truck. Sometimes I wonder if I am just making this up, but I figured I would include it for the diagnostics.

My next course of action would be to completely remove the belt for the air-conditioner, since nothing else is on the same belt. I can then drive it around to see if the air-conditioner line is at fault. That would allow me to check the pulleys for the power steering line while I have it all off. It's just that I am very limited on time and don't seem to be getting anywhere.

I would greatly appreciate any help in this matter.

tacoma man.

mine had been squeaking but i sprayed some of that belt dressing on and it stopped. but the idler pully shouldnt wobble.

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Brian R.

Since the A/C is not under load, I doubt you are hearing the A/C belt. Might be your water pump.

Your vibration is probably unrelated to the noise. When it is vibrating at idle, remove the plug wires one at a time and see if one of the cylinders is unaffected by removing the wires. That is the cylinder that is causing the trouble. If it is a general problem with all the cylinders, none of the wires will have a larger effect than the others.