Clinking rear noise
Thread Starter
3rd Gear
Joined: Oct 2020
Posts: 3
Likes: 0
Clinking rear noise
Hey guys, wondering if anyone has come across this clinking relay like noise from the rear. I just recently moved to Belgium and a week after driving this noise came up. Really loud outside as well. 2017 GS 24k miles no mods. Any help will be very much appreciated!
Video
Video
Race Director
Joined: Mar 2001
Posts: 19,965
Likes: 6,770
From: Bonneville Salt Flats
It doesn't sound, at least at first, like it is synced to the engine, but since you didn't rev it at all, it's impossible to tell for sure. So, I'm suggesting getting it up on a lift where you can run the engine and give it a good going over, perhaps with a stethoscope to help pinpoint the source. Good luck. 
Thread Starter
3rd Gear
Joined: Oct 2020
Posts: 3
Likes: 0
Due to Covid and how hard its hitting in Belgium I have no access to lifts. After a few drives I've noticed a few more details. Noise is between 1200 to 4800 Rpms, does it on any gear and on any surface. You are correct Avanti, it does not really follow engine speed as it does not quicken when it starts around the 1200 rpms to 4800 rpms. Does not seem to come on at all in 5k Rpms and above. I'm very uneasy about this since I'm so far from any near chevy dealer and will not be heading to the US for another 3 years.
Last edited by John Santiago; Oct 31, 2020 at 08:36 AM.
Heel & Toe
Joined: Oct 2020
Posts: 23
Likes: 1
From: Texas
Check NPP valves
Do you have performance exhaust system? If so,
see my thread (I called it clanging instead of clinking). I posted video where you can see the NPP valve of passenger side exhaust repeatedly opening and closing. Similar sound to your video.
see my thread (I called it clanging instead of clinking). I posted video where you can see the NPP valve of passenger side exhaust repeatedly opening and closing. Similar sound to your video.
Thread Starter
3rd Gear
Joined: Oct 2020
Posts: 3
Likes: 0
I suspected the exhaust as nothing else would come close to that sound. You are absolutely correct, I removed the fuse and took it for a drive. Not one sound came out the rear. I cannot thank you enough!
Heel & Toe
Joined: Oct 2020
Posts: 23
Likes: 1
From: Texas
NPP Issue
Glad that helped. Let me know if you ever find the root cause. I know that removing the fuse or installing the Mild2Wild switch eliminates the symptom, but at the cost of disabling the exhaust management system.
Unfortunately that is not an option for me, as my wife hates loud exhaust music. So whenever she is in the car we operate in Stealth or Tour modes, and my clanging valve(s) are a problem. So I still need to find the root cause and fix it.
Unfortunately that is not an option for me, as my wife hates loud exhaust music. So whenever she is in the car we operate in Stealth or Tour modes, and my clanging valve(s) are a problem. So I still need to find the root cause and fix it.
Heel & Toe
Joined: Oct 2020
Posts: 23
Likes: 1
From: Texas
Root Cause
FYI I confirmed that my problem is a failure in the actuator. See my thread for more detail, but if your problem is the same, the way to restore full functionality of the performance exhaust is to replace the faulty actuator(s). This is pretty easy to do.
