Ringing noise when..

My 05 silverado has developed sort of slight ringing noise only when the air conditioning is on and I'm accelerating or driving but not when idling. It still does it when the cruise is set. And the noise seems to have a pattern of about every 10 seconds. I have it recorded on my cell phone. Maybe I can upload it later on.

I took my truck in for an oil change/ rotate tires/ and a 24 point inspection to the local dealership. I told the service rep what it was doing and he said it would still cost me 90 bucks to check it out but it sounded to him like a loose heat sheild from what I described above.

It's hard for me to pin point where the noise is coming from execpt the vents or front since I have to be driving to hear it.

I did have a guy stand with the hood up to listen to the belts but he couldn't hear the noise when I could slightly hear it inside as I rev'd the engine.

Any ideas?

My 05 silverado has developed sort of slight ringing noise only when the air conditioning is on and I'm accelerating or driving but not when idling. It still does it when the cruise is set. And the noise seems to have a pattern of about every 10 seconds. I have it recorded on my cell phone. Maybe I can upload it later on.

I took my truck in for an oil change/ rotate tires/ and a 24 point inspection to the local dealership. I told the service rep what it was doing and he said it would still cost me 90 bucks to check it out but it sounded to him like a loose heat sheild from what I described above.

It's hard for me to pin point where the noise is coming from execpt the vents or front since I have to be driving to hear it.

I did have a guy stand with the hood up to listen to the belts but he couldn't hear the noise when I could slightly hear it inside as I rev'd the engine.

Any ideas?

you have an underhood noise only when the AC is on ...so the dealership service manager THINKS its a heat shield ....LOL !!!!!

My "guess" is this maybe the ac compressor idler pulley or the ac compressor clutch bearing .....remove the ac belt inspect for any worn bearings etc....replace belt if worn.....make sure idler is free to move correctly to maintain proper belt tension...

My 05 silverado has developed sort of slight ringing noise only when the air conditioning is on and I'm accelerating or driving but not when idling. It still does it when the cruise is set. And the noise seems to have a pattern of about every 10 seconds. I have it recorded on my cell phone. Maybe I can upload it later on.

I took my truck in for an oil change/ rotate tires/ and a 24 point inspection to the local dealership. I told the service rep what it was doing and he said it would still cost me 90 bucks to check it out but it sounded to him like a loose heat sheild from what I described above.

It's hard for me to pin point where the noise is coming from execpt the vents or front since I have to be driving to hear it.

I did have a guy stand with the hood up to listen to the belts but he couldn't hear the noise when I could slightly hear it inside as I rev'd the engine.

Any ideas?

I would be happy to look into this further for you. In order to do some further research, I will need the VIN for the vehicle as well as the current mileage. Hope to hear from you soon. Thank you.

Tricia, GM Customer Service

VIN- 1GCEK19BX5Z147004

This 1st clip video isn't a good representation of the sounds actual tone but it does demostrate the rhythm and length of the sound on average. Noise starts right before half way of video clip.
http://tinypic.com/player.php?v=wcn2nn&s=7

This 2nd clip is what the noise actually sounds like to the ear. The ringing starts about 3 seconds in, then fades out. I'm sure it did it again before the video ends but too light to pick up over the vent noise.
http://tinypic.com/player.php?v=96miq9&s=7

I have looked into recall information as well as bulletins for the vehicle, but I was unable to find anything that matches this situation. I would recommend continuing to work with your local dealership regarding this concern. Please feel free to keep us updated regarding the concern. Thank you in advance.

Tricia, GM Customer Service.

My 05 silverado has developed sort of slight ringing noise only when the air conditioning is on and I'm accelerating or driving but not when idling. It still does it when the cruise is set. And the noise seems to have a pattern of about every 10 seconds. I have it recorded on my cell phone. Maybe I can upload it later on.

I took my truck in for an oil change/ rotate tires/ and a 24 point inspection to the local dealership. I told the service rep what it was doing and he said it would still cost me 90 bucks to check it out but it sounded to him like a loose heat sheild from what I described above.

It's hard for me to pin point where the noise is coming from execpt the vents or front since I have to be driving to hear it.

I did have a guy stand with the hood up to listen to the belts but he couldn't hear the noise when I could slightly hear it inside as I rev'd the engine.

Any ideas?

the looking into GM service TSB etc is not going to find the noise issue. looking and using the proper equipment , and checking the components I mentioned in your engine compartment , will assist you to finding the noise..

you will have to find the noise................

If you hire some auto mechanic to repair this , they will change parts at your expense until they get the correct component..this is expensive.

using a rubber hose one end stuck in your ear the other end to probe the engine compartment for the source.

post back what you found .

Haven't had time to get a hose and listen yet as suggested. But i did run across this TSB that deals with a ringing noise when the compressor does it thing but don't know all the details of it.
TSB Number: 040138014