gdonn7

https://imgur.com/a/gGrCc3Y
Happens when the car is idling after driving for a while. A few days ago the car was idling and it wasn't making the sound, as soon as I turned on the AC, it started then stopped when I turned off the AC...

Carrera2RS

Not sure I can make out which sound it's difficult to hear any differences other than when the door side pocket is shut and it just seems a bit quieter ?

SpectreH

Any chance the belt is worn or the tensioner not holding proper belt tension? Doesn’t really sound like belt noise, but based on your AC on/off comment, that popped into my mind.

gdonn7

The squeaky sound is consistent throughout the video, it doesn’t get quieter. I was trying to get the car to make the sound all day but it finally did it when I got to a bar lol. I would’ve lifted the hatch, but didn’t want to get dirty as she needed a bath.

The night before, I drove around for about 2 hours trying to get it to make the sound so I can record a proper video with the engine lid open lol

gdonn7

​​​​This belt’s tension is as firm as could be and looks like it’s great condition.

groovzilla

Video is hard to determine the exact sound - Idler pulleys could be worn out
When you drive the car and increase speed does the sound get louder at certain RPM?

gdonn7

Yeah, I’ll try to get a better video next week. When driving the car you don’t hear it. If I’m idling and it’s making the noise, and I blip the throttle, it’ll stop and when the RPMs drop, it’ll start making the sound again.

TheBruce

It sounds like a bearing from one of the accessories. If the sounds starts/stops when turning the ac on/off I would check the tensioner, AC clutch bearing, and alternator. Pull the belt off and see If they all spin smoothly with no roughness.

I had a weird rattle at idle when I first got my 997 that I investigated for weeks. It would hear it after driving for a bit when pulling up to a stop light. And it would start/stop when I turned the AC off. I tore the clutch bearing apart (pain in the ***) and replaced the tensioner with no result. Turns out the car was a bit low on AC refrigerant and it was causing the AC lines to resonate. I topped it off and have never heard it since.

gdonn7

Hmmm, thanks for this. I'll try to get it to make the sound this week with the hatch open to see if it's coming from one of the places you mentioned.

groovzilla

Hard to believe you had any time to do this repair considering the time involved in the lengthy Posts you used to write to ClimaRepair regarding the substandard *****

Khloesdad

My guess is idler pulley bearing. Pull the belt loose and spin each one.

TheBruce

Ha! I thankfully totally forgot about that guy I can't believe he was the most annoying thing about my 50k miles of 997 ownership. Compare that to owning a 50 year old wooden boat and a 7yr old land rover, I have bigger hassles on a weekly basis, not least of which they both leak about the same

Ps - the ones I got from MACarbon are perfect and are still like new after 3 years.

gdonn7

Update, I stopped by a shop but they were very busy so the owner came out and heard the sound and put his foot on the left exhaust tip and it stopped & started back up when he removed his foot. He didn't have time to investigate any further, any ideas on what it could be? Tips are on snug

Better video of the sound
https://imgur.com/a/PQdcX8P

RandyVW

Does it stop it for you when you try the foot on exhaust tip??

If it's truly a 100% on when A/C on and off when A/C off, I'd try to get a second ear in where you (or the 2nd person) can get their ear as close to the location of the noise as possible.......A/C on/off and/or foot on/off the exhaust tip.

(Another pro tip for finding sounds can be a short length of tubing (anything, even old garden hose) to hold from your ear to the motor as a stethoscope to pinpoint more closely where a sound is coming from. Especially when you don't want to get your head/ear/hair too close to a bunch of pulleys runnin' a belt under a serious horsepower.

Bruce In Philly

2009 C2S 197K miles

It may be an exhaust leak. It was for me and happened in both side mufflers over time. The sound ... I can't really hear anything in that recording... but pressing on the muffler tips is a dead giveaway for a leak IMO. Pressing on the tips was my acid tests for discovering my leaks (each muffler, different years). Regarding the AC, the engine's computer compensates the throttle for the changing load and this could crest some sort of air volume threshold that you can hear/not hear... acoustics are really bizarre in these situation.

You can put a mirror up in there from underneath and you will see black carbon around the weld points (dead giveaway)... the muffler cracks/tears in only one place ... at least I never heard of any crack elsewhere than this one weld. Easy diagnosis.

IIRC, the first noise I heard was some sort of whistling sound that very slowly grew into a more of a rumble then truck sound... I think I went for about one year before I finally figured out what the noise was and for a while, I suspected the pulley. I even stopped at the dealer and the service rep came out and immediately said it may be an exhaust leak... I didn't believe him as it didn't have the truck sounds I was used to with classic GM rotted exhausts I grew up with in PA.

Read up here for entertainment: https://rennlist.com/forums/997-foru...lp-please.html

Peace
Bruce in Philly (now Atlanta)