Pulley Bearing Noise
 

I have a 2003 Mitsubishi Montero Limited with 73K on it. I've had it since it was new. No major service as of yet (original timing belt). I recently replaced the serpentine belt. I do most of my own maintenance and am looking for information concerning a chirping noise that appears to be from one of the pulleys on the driver's side of the engine (may even be inside the timing cover :mad:). It only happens when you rev the engine up to about 2000 rpm (starts the noise at the top of the rev and chirps on it's way down). From what I've read so far this may be anything from a serpentine belt pulley or serpentine belt tensioner replacement to a full blown timing belt replacement (with tensioner pulleys etc). With the exception of the special tools I'm game for a timing belt replacement, haven't even changed the sparks yet, and the valve covers are leaking so this may be my opportunity to knock alot of maintenance out. I definately want to start simple and rule out the simple stuff first though.....Any tips on what I should do before I start buying hundreds of dollars in parts or hand it to the dealer?

I would try simple steps first; such as remove the belt and start/idle for short time to rule out tensioner and pulley. The outcome will determine your next move.

Start with the easy stuff first
 

It sounds like a bearing on the serpentine belt tensioner pulley. I recall mine ('01 Montero) went out at about 75-80k. It's an easy fix. You can take off the serpentine belt and move the pulleys by hand. The bad one will make lots of funny noises and will have excessive play. If it's a tensioner, it is an easy replacement - it only takes one or two bolts to swap it. Start with the easy things first. Then move on down the line. Good luck.

If you can find an old Stethoscope it sure helps focusing on the location within the front end of the engine's anatomy.

Todd

Thanks for the tips, I'll give it a shot this weekend. Thanks,

Chris

Replaced Idler Pulley
 

Well I replaced the idler pulley for around 38 dollars at advance and still have noise. I did remove the serpentine belt and run the engine, with no chirping/noise, so at least I know it is NOT the timing belt or timing belt tensioner. It seems to be coming from the driver side of the engine, so it may be my power steering pump pulley (which doesn't look like it can be replaced) or some other pulley. I did notice that the serpentine belt moves side to side on the belt tensioner pulley, the oscillation kind of matches the chirping sound. So my next replacement will be the belt tensioner. Any thoughts?

Replaced serpentine belt tensioner
 

Still making noise after I replaced the tensioner. I think it may be in the power steering pump, that will be the next pulley I replace, maybe its the pump itself?

Have you used a Stethoscope to isolate the sound

Todd

replace the belt

replaced second idler pulley
 

I replaced the grooved idler pulley today. I found a youtube video from dayco that helped with the trouble shooting. Apparently the chirping sound is from a slight misalignment in the grooved pulleys between each other. this misalignment causes the chirping as the grooved side of the belt engages with the grooves in the pulleys. The way to test it is to squirt some water on the belt and if the chirping stops you have an alignment issue. I did this and sure enough it stopped. I pulled the belt off and the grooved idler pulley wobbled just a little on its bearing. The power steering pump also had some play but it was laterally on its shaft (in and out). Long story short is that I replaced the grooved ilder pulley and it seemed to take care of the problem. I will check again tomorrow when the car is cold and see if this fixed it and repost. Mxmikie, I already replaced the belt, it is new.