Knocking / Clicking rear sound ?

[cal602]

Hi everyone

I’ve noted a predominant knocking type sound from the rear. I am pretty sure this is only happening when the car is exposed to extreme cold. In those conditions, the sound is evident on start up when I accelerate or ease off the accelerator, then gradually dissipating after a period of driving. I have the sound saved to a voice memo, but can’t attach it here unfortunately. It anyone is experiencing something similar, any insight would be appreciated. The dealership won’t do anything unless they hear it, and it’s hard to coordinate a service appointment with extreme cold days.

Many thanks.

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[eponey]

Does it go away with use or only happen at lowish speeds, did you have your tires rotated recently?

 

[Mach1E]

Hi everyone

I’ve noted a predominant knocking type sound from the rear. I am pretty sure this is only happening when the car is exposed to extreme cold. In those conditions, the sound is evident on start up when I accelerate or ease off the accelerator, then gradually dissipating after a period of driving. I have the sound saved to a voice memo, but can’t attach it here unfortunately. It anyone is experiencing something similar, any insight would be appreciated. The dealership won’t do anything unless they hear it, and it’s hard to coordinate a service appointment with extreme cold days.

Many thanks.

Is it worth a trip to the dealer though?

If it only happens in extreme cold and your car is functioning properly, it sounds like nothing is broken to fix.

Even if they can replicate the sound (which you said is unlikely due to the circumstances), then what?

And a recording of the sound won’t likely help in this situation to diagnose.

Personally I would just live with it rather than go through the frustration of sending the dealer on a ghost hunt only to tell you that they can’t replicate the issue.

 

[cal602]

Does it go away with use or only happen at lowish speeds, did you have your tires rotated recently?

Does it go away with use or only happen at lowish speeds, did you have your tires rotated recently?

Does it go away with use or only happen at lowish speeds, did you have your tires rotated recently?

Does it go away with use or only happen at lowish speeds, did you have your tires rotated recently?

It does seem to go away with use and I only hear it at lowish speeds. It also seems to be related to cold temps if that makes sense. I switched to winter tires but that was back in November.

 

[ack154]

I think mine is doing this also - and I also just started noticing it as it's been REALLY cold lately (-11 F this morning).

Basically, it's one single "knock" when I either begin moving forward or lift off the accelerator. I notice it most at low speed (since it's quieter, really). And I can easily reproduce it by lightly pressing and releasing the accelerator.

I've so far assumed that it is just cold related but am monitoring it for now when it begins to warm back up (even at or above freezing would be great right now).

One thing I have not done yet, because I keep forgetting, is to turn off AdvanceTrac (to completely turn off regen) and see if it still does it. I suspect it will not but just haven't tested.

 

[cal602]

I think mine is doing this also - and I also just started noticing it as it's been REALLY cold lately (-11 F this morning).

Basically, it's one single "knock" when I either begin moving forward or lift off the accelerator. I notice it most at low speed (since it's quieter, really). And I can easily reproduce it by lightly pressing and releasing the accelerator.

I've so far assumed that it is just cold related but am monitoring it for now when it begins to warm back up (even at or above freezing would be great right now).

One thing I have not done yet, because I keep forgetting, is to turn off AdvanceTrac (to completely turn off regen) and see if it still does it. I suspect it will not but just haven't tested.

I shut off one pedal and still happens. Where is the AdvanceTrac setting ?

 

[ack154]

I shut off one pedal and still happens. Where is the AdvanceTrac setting ?

On the GT you can hold down the traction control button until it shuts off.

 

[Teslaeata]

Go to dealer is what I would do and if they say they can’t find the fault, make them go out with you because you can probably replicate the conditions under which the sound appears, good luck?

 

[eponey]

Check your lug nuts, make sure they are to spec should be 150 ftlb afaik but check your manual, especially after the rotation.

 

[ack154]

As suspected, it does NOT do it when AdvanceTrac is off.

 

[azerik]

I have it, sounds like a half shaft at the wheel. My sounds isn't once. it's cluck clunk cluck getting faster as speed increases. It gets quieter the warmer (I assume) the joint gets. So the longer driven the more it goes away.

I know I can move my front shafts in and out and it makes a hard metal clank. Rear noise only when below 50 degrees. Which is interesting as my garage is dropping to just over 50 degrees at 8am just before my drive. I don't have it until about 2 minutes into my drive while under decent acceleration (ambient temps in low 40's).
My lugs etc are all tight, it's a driveline thing. Mark B. had mentioned a friend of his also had this and got it fixed under warranty. Mine goes away within 4 or so minutes. I however am left with a driveline vibration nearly the entire drive but under acceleration I can cause the rear of the car to rumble. I'm in the drive it till it breaks, then the dealer can't deny it.

 

[cal602]

I have it, sounds like a half shaft at the wheel. My sounds isn't once. it's cluck clunk cluck getting faster as speed increases. It gets quieter the warmer (I assume) the joint gets. So the longer driven the more it goes away.

I know I can move my front shafts in and out and it makes a hard metal clank. Rear noise only when below 50 degrees. Which is interesting as my garage is dropping to just over 50 degrees at 8am just before my drive. I don't have it until about 2 minutes into my drive while under decent acceleration (ambient temps in low 40's).
My lugs etc are all tight, it's a driveline thing. Mark B. had mentioned a friend of his also had this and got it fixed under warranty. Mine goes away within 4 or so minutes. I however am left with a driveline vibration nearly the entire drive but under acceleration I can cause the rear of the car to rumble. I'm in the drive it till it breaks, then the dealer can't deny it.

My sound is more of a knocking / creaking sound. It does not get faster as I accelerate.

 

[azerik]

If the lugs arn't tight enough the one clunk can be the brake pads grabbing and letting go. The rotor can move a little. They're designed that way, but they rely on the wheel being torqued to 150 ft/lbs a lug to hold the rotor. I experienced rotor noise when my front wheel was only torqued to about 100 ft/lbs. Creaking could be really cold rubber bushings (there's like 11 of them per side in the rear).

 

[Rassman]

I have the sound as well. 23 Premium 4x. I will describe it as a click or knock that happens only when the excellerator is push as the car first moves or when I first touch the brake (not in 1 pedal mode). It's like something in the drive system shifts or realigns. It only happens in the cold (below 45 F) and goes away the longer I drive. Took it to the dealer for the wiper motor recall, and of course it wasn't happening. Kind of happy about that as I don't trust the dealer not to mess something else up. I checked lug torque - No change. Turned off Advance Trac - no change. The onlt factor that has an effect it temperature. Above about 45 F. No noise.

I sure hope someone here (or the group) figures this out.

 

[Teslaeata]

Hi everyone

I’ve noted a predominant knocking type sound from the rear. I am pretty sure this is only happening when the car is exposed to extreme cold. In those conditions, the sound is evident on start up when I accelerate or ease off the accelerator, then gradually dissipating after a period of driving. I have the sound saved to a voice memo, but can’t attach it here unfortunately. It anyone is experiencing something similar, any insight would be appreciated. The dealership won’t do anything unless they hear it, and it’s hard to coordinate a service appointment with extreme cold days.

Many thanks.

I think I had this, rear wheel bearings changed under warranty cured it, whether it was the wheel bearings that were faulty or just the disturbance or reseating of something cured it - driveshaft splines, hub nut security or something else - I can’t be sure.

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