[rusya119]

Hi everyone! I've encountered an interesting issue with my car. I often notice a cricket-like sound while driving. It comes from different sides and is quite loud and clear. It frequently occurs when I press the gas pedal lightly (about 5%-10%), causing the body to tilt slightly. However, the sound can also happen when driving straight, braking, etc. It appears more often on uneven roads, for instance, if the road has a slight bump or incline. But mostly, it's random.

It's a very strange and puzzling noise. I managed to capture it on video at the very beginning by pressing the gas pedal lightly on an almost flat road. The sound is similar to brake squeaking but happens randomly. What could be the problem? Has anyone else experienced this? I replaced the brake pads with new ones, but it didn't help.

https://youtube.com/shorts/uTl_UO1ewyA

[KYVOM1LE]

I also have a very similar sound under very light acceleration. It sounds like a bird chirping...

[Rogueleader_92]

I have a similar sound but it sounds like its just plastic rubbing together in the back of the cabin

[rusya119]

Originally Posted by KYVOM1LE

I also have a very similar sound under very light acceleration. It sounds like a bird chirping...

Today I drove it and realized what the problem was. When switching from v4 to v8, if you press the gas, a creaking noise occurs. It's a valve issue that I need to lubricate.

[arpad_m]

Yup, if it's an automatic, the noise is more than likely to come from the AFM valves. These use the same mechanism as the NPP exhaust valves and can squeak just as much. Although AFM is tu(r)ned off on my car, I regularly lubricate the NPP valves with Drislide and hear no squeaking whatsoever.

[Speak99]

I have this noise too. How do i lube these up?

[arpad_m]

Originally Posted by Speak99

I have this noise too. How do i lube these up?

Believe it or not, GM even issued a TSB on this one, pretty early during the first model year run: https://static.nhtsa.gov/odi/tsbs/20...34535-9999.pdf

The document covers only the NPP valves, but a similar treatment should be applicable to AFM valves. Good luck

[DamonZ28]

Originally Posted by arpad_m

Believe it or not, GM even issued a TSB on this one, pretty early during the first model year run: https://static.nhtsa.gov/odi/tsbs/20...34535-9999.pdf

The document covers only the NPP valves, but a similar treatment should be applicable to AFM valves. Good luck

Do you just flip the car between driving modes, with the exhaust set to Auto, to "command the flow control functioning numerous times on all valves?"

[arpad_m]

Originally Posted by DamonZ28

Do you just flip the car between driving modes, with the exhaust set to Auto, to "command the flow control functioning numerous times on all valves?"

Yup.

AFM valves cannot be controlled this way, though, they'll activate together with AFM. An advanced enough scan tool may be able to command them to flip (I've had AFM tuned out since 2018, so I'm not sure).

[cdb95z28]

Originally Posted by arpad_m

Yup, if it's an automatic, the noise is more than likely to come from the AFM valves. These use the same mechanism as the NPP exhaust valves and can squeak just as much. Although AFM is tu(r)ned off on my car, I regularly lubricate the NPP valves with Drislide and hear no squeaking whatsoever.

This^^^

I experienced the squeaking noise in my A10 equipped SS 1LE while I was running the fun roads in the Smokey Mountains. I had concluded it was the AFM valves located ahead of the diff on the exhaust. I believe the heavy part throttle use combined with high heat was causing the noise.