Hi All,

Wanted to get feedback on a ringing noise i am hearing on a new to me 2006 MCS with 58k miles. The noise appears to be coming from the passenger side pulley area and only happens when in drive/reverse (video below). The noise is pretty faint and can only hear it when driving through a garage or next to a wall. The ringing is most prevalent when first shifting into drive, or reverse. After a few seconds it appears to quiet down but still makes very slight noise. I have done the below diagnostics but still can't pinpoint it. Any advice would be greatly appreciated!

• Harmonic balancer (visually) looks to be in good condition. No cracks on rubber.
• Took a stethoscope to the pulleys and could not pinpoint the noise. Idler pulley appears to be quiet.
• Belt tensioner - after talking to a few people, most are guessing its the belt tensioner. However if it is failing, does it using make a ringing noise? or how can i diagnose this issue before blindly buying parts.
• Timing chain tensioner - any chance it could be this? although videos of a failed timing chain tensioner seem to make a different noise.

I have attached a video below for reference. As previously stated, the ringing is quite loud in the video, but in person it is much more faint. Driveability does not seem to be affected. Any feedback on where to start would be great appreciated. Thanks in advance!

 

bump... just wanted to see if anyone had any insight on this issue. Thanks in advance!

 

It's your idler pulley, just changed mine a few weeks ago. Remove your belt and spin your adler pulley and your alternator pulley, you should be able to feel if the bearings are going.

 

thanks, i have an idler pulley arriving today (thanks amazon prime!). Hopefully that does the trick.

 

Realized i never followed up on this. Installed the gates idler pulley from amazon and ringing noise has gone away. Thanks all!

 

Good deal. I thought I had isolated the idler pulley, so replaced it. Alas it was the tensioner pulley!