Knocking Sounds?

[yehielid]

Hi all! I’m having a very bizarre issue with our 2021 Jeep Grand Cherokee L, Limited 4x4. We have just about 2,000 miles and a very bizarre knocking sound has developed that sounds like an engine or transmission knock or vibration that is very challenging to replicate at the dealer due to the time it occurs under certain conditions only. When it happens, the vibration can be felt under the passenger floorboard relatively violently.

The knocking sound only develops when the vehicle has been driven about 30 or more miles and the motor and transmission are very warm. It makes no sound when in reverse, neutral, or park. Only drive. If just doing short mileage drives, the problem never develops. I had my wife put the vehicle in drive while I looked for the location of the knock and it seems like it’s not coming from the motor but again somewhere near the transmission and more abundant under the front passenger floorboard area.

Has anyone encountered this issue or know a cause? Bad transmission/motor mounts? Faulty pulleys?

I plan to drive it straight to the dealer the next time it exhibits symptoms. Any help or similar narratives are greatly appreciated!

 

[Grand Cherokee L]

Hi all! I’m having a very bizarre issue with our 2021 Jeep Grand Cherokee L, Limited 4x4. We have just about 2,000 miles and a very bizarre knocking sound has developed that sounds like an engine or transmission knock or vibration that is very challenging to replicate at the dealer due to the time it occurs under certain conditions only. When it happens, the vibration can be felt under the passenger floorboard relatively violently.

The knocking sound only develops when the vehicle has been driven about 30 or more miles and the motor and transmission are very warm. It makes no sound when in reverse, neutral, or park. Only drive. If just doing short mileage drives, the problem never develops. I had my wife put the vehicle in drive while I looked for the location of the knock and it seems like it’s not coming from the motor but again somewhere near the transmission and more abundant under the front passenger floorboard area.

Has anyone encountered this issue or know a cause? Bad transmission/motor mounts? Faulty pulleys?

I plan to drive it straight to the dealer the next time it exhibits symptoms. Any help or similar narratives are greatly appreciated!

I think I am having the same sounds, but No vibration. It happens on D only when the car is stopped

 

[ds123]

FINALLY, I found someone on this forum with the same problem. I’ve had my Jeep since September -21 and the problem started around 2k miles, currently at 13k. Only happens at idle AFTER 30-40 miles and the dealer said nothing is wrong with it. Still happens and the knocking sound is so annoying. Please keep me updated if you find anything out!

 

[yehielid]

I think I am having the same sounds, but No vibration. It happens on D only when the car is stopped

When you hear the sound, please see if you can feel any vibration on the right passenger floorboard if you lay your hand flat. It’d be good to see if we can all self diagnose and isolate the location. My sound is the exact same. Only occurs in drive. Such a bizarre issue.

 

[yehielid]

FINALLY, I found someone on this forum with the same problem. I’ve had my Jeep since September -21 and the problem started around 2k miles, currently at 13k. Only happens at idle AFTER 30-40 miles and the dealer said nothing is wrong with it. Still happens and the knocking sound is so annoying. Please keep me updated if you find anything out!

Wow, this is really sounding like it’s not a singular issue and comes on right around the same driven mileage and odometer reading. I’m going to safeguard it exhibits the right signs and symptoms before I take it to the dealer or else they’ll kick it back with the classic “couldn’t replicate the issue.” I’m starting to think it could be a faulty transmission mount, transmission component, faulty pulley, or heaven forbid improper engine seal causing pinging when at high operating temperatures. Although the 3.6 is relatively solid, I feel like Jeep messed with the design to optimize fuel economy which could be causing some issues as well by faulty design when under load in drive. Keep us posted if you find any remedy or causation as well.

 

[Mike1597]

I had the same issue. It was the heat shield.

 

[yehielid]

I had the same issue. It was the heat shield.

Was it improperly aligned/installed?

 

[Mike1597]

There is a TSB on incorrect heat shields being installed. The service tech told me the heat shield was the issue and they fixed it. They said the heat shield would heat up and expand causing a clearance issue which resulted in a popping noise.

 

[Bobolikesjeeps]

Some of you guys need to find new dealerships. I have not had this problem but it was still addressed by my dealer during my last service appointment.

 

[yehielid]

Some of you guys need to find new dealerships. I have not had this problem but it was still addressed by my dealer during my last service appointment.

Amen!

 

[Grand Cherokee L]

There is a TSB on incorrect heat shields being installed. The service tech told me the heat shield was the issue and they fixed it. They said the heat shield would heat up and expand causing a clearance issue which resulted in a popping noise.

Thanks for the info. How did they fix it? Did they replace it?.

 

[Grand Cherokee L]

When you hear the sound, please see if you can feel any vibration on the right passenger floorboard if you lay your hand flat. It’d be good to see if we can all self diagnose and isolate the location. My sound is the exact same. Only occurs in drive. Such a bizarre issue.

I will try to do this the next time

 

[Bbiggers340]

I have this problem also but I never knew what it was

 

[yehielid]

Update:
I was able to have the dealer replicate the issue after a 20 minute drive. The dealer service manager diagnosed the vehicle with faulty motor mounts. The technician also mentioned that there is a a revised TSB on the matter. Not sure the mount replacement will fix the issue or if this is the true cause including a revised TSB. I’ll keep you all posted!

 

[Grand Cherokee L]

Update:
I was able to have the dealer replicate the issue after a 20 minute drive. The dealer service manager diagnosed the vehicle with faulty motor mounts. The technician also mentioned that there is a a revised TSB on the matter. Not sure the mount replacement will fix the issue or if this is the true cause including a revised TSB. I’ll keep you all posted!

Any update. Did they diagnose the issue?

 

[yehielid]

Any update. Did they diagnose the issue?

They are still in the process of replacing the mounts due to shipping delays. Should have it back by the end of the week. I’ll be able to determine if this was the remedy at that time. I’ll keep everyone posted.

 

[Grand Cherokee L]

They are still in the process of replacing the mounts due to shipping delays. Should have it back by the end of the week. I’ll be able to determine if this was the remedy at that time. I’ll keep everyone posted.

Thanks. Engine mounts or transmission mounts?. I read on a Facebook group that people were told that it is the purge valve that is making this clicking noise and that should be normal

 

[yehielid]

Thanks. Engine mounts or transmission mounts?. I read on a Facebook group that people were told that it is the purge valve that is making this clicking noise and that should be normal

Service manager said engine mount. The sound I hear is in alignment with that diagnosis. I’m eager to get it back to see if this really was the cause. This sound is pretty pronounced. I don’t believe it’s the purge valve for my issue.

 

[Grand Cherokee L]

Service manager said engine mount. The sound I hear is in alignment with that diagnosis. I’m eager to get it back to see if this really was the cause. This sound is pretty pronounced. I don’t believe it’s the purge valve for my issue.

Okay. Keep us updated. I hope it solves your issue

 

[Grand Cherokee L]

Okay. Keep us updated. I hope it solves your

Update:
I was able to have the dealer replicate the issue after a 20 minute drive. The dealer service manager diagnosed the vehicle with faulty motor mounts. The technician also mentioned that there is a a revised TSB on the matter. Not sure the mount replacement will fix the issue or if this is the true cause including a revised TSB. I’ll keep you all posted!

Any luck with the repair?