70 MPH Thumping sound

[Bill33525]

My 2022 RWD with, madei in Germany, Goodyear 21" tires makes a sound like the tires have a flat spot @ 70 MPH. The sound is heard on several different stretches of a major highway here in Central Fl. The stretches of blacktop are fairly new and do not appear to have any visual faults. The thumping sound is centered sharply around 70 MPH. Any ideas?

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[DerekS]

Have the tires been patched? I had this on a Boxster once after a flat repair where they didn’t balance the wheel properly.

 

[Bill33525]

Hello Derek-
No Patches and the tires have good thread, two are almost new. Finally, they just did a road force balance on all the tires.

 

[Gino]

My 2022 RWD with, madei in Germany, Goodyear 21" tires makes a sound like the tires have a flat spot @ 70 MPH. The sound is heard on several different stretches of a major highway here in Central Fl. The stretches of blacktop are fairly new and do not appear to have any visual faults. The thumping sound is centered sharply around 70 MPH. Any ideas?

Does the thumping sound happen when accelerating up & through 70mph as well as when coasting down from a higher speed such as 80mph coasting down to 70mph?
If the thumping is there during acceleration but not when coasting down to 70mph then the problem is not your tires but likely the drive components.

My 2022 RWD with, madei in Germany, Goodyear 21" tires makes a sound like the tires have a flat spot @ 70 MPH. The sound is heard on several different stretches of a major highway here in Central Fl. The stretches of blacktop are fairly new and do not appear to have any visual faults. The thumping sound is centered sharply around 70 MPH. Any ideas?

My 2022 RWD with, madei in Germany, Goodyear 21" tires makes a sound like the tires have a flat spot @ 70 MPH. The sound is heard on several different stretches of a major highway here in Central Fl. The stretches of blacktop are fairly new and do not appear to have any visual faults. The thumping sound is centered sharply around 70 MPH. Any ideas?

Does the thumping sound happen at 70mph during acceleration as well as when coasting back down from a higher speed to 70mph? I had a similar vibration on a Honda Accord years ago and the dealer kept telling me it was the tires. I new that was incorrect because I had the tires high speed balanced already.
Then the dealer boneheads told me it was likely an engine mount which was also a really uneducated idea so I tested the vehicle driving under load up and through 65mph when the vibration started but when I coasted back down from 80mph down through 65mph the vibration was not there.
I told them it was the CV joint which drives the wheels from the motor.
They eventually confirmed it was the CV joint but in their defense they said they are no allowed to go above the 65mph speed limit in California so they could not replicate the test I performed coating down from 75-80mph to 65mph to show there was no vibration when the drive was not under load conditions.
At least you can determine if the problem is your tires/wheels or the drive components themselves at 70mph. Good luck!

 

[Bill33525]

Does the thumping sound happen when accelerating up & through 70mph as well as when coasting down from a higher speed such as 80mph coasting down to 70mph?
If the thumping is there during acceleration but not when coasting down to 70mph then the problem is not your tires but likely the drive components.


Does the thumping sound happen at 70mph during acceleration as well as when coasting back down from a higher speed to 70mph? I had a similar vibration on a Honda Accord years ago and the dealer kept telling me it was the tires. I new that was incorrect because I had the tires high speed balanced already.
Then the dealer boneheads told me it was likely an engine mount which was also a really uneducated idea so I tested the vehicle driving under load up and through 65mph when the vibration started but when I coasted back down from 80mph down through 65mph the vibration was not there.
I told them it was the CV joint which drives the wheels from the motor.
They eventually confirmed it was the CV joint but in their defense they said they are no allowed to go above the 65mph speed limit in California so they could not replicate the test I performed coating down from 75-80mph to 65mph to show there was no vibration when the drive was not under load conditions.
At least you can determine if the problem is your tires/wheels or the drive components themselves at 70mph. Good luck!

I will try this test, I discovered the problem when driving at 70 MPH since that's the speed limit in the two areas of highway where the problem was experienced. Thanks for the reply, this is very helpful.

 

[Gino]

I will try this test, I discovered the problem when driving at 70 MPH since that's the speed limit in the two areas of highway where the problem was experienced. Thanks for the reply, this is very helpful.

It’s a shot to try to pin down the problem but I know nothing about the Porsche electric motor drive system. If you can at least eliminate the tires & wheels as the source then Porsche will be able to figure out what could make this sound in their drive when it is under load. Hope you find out soon. Good luck!

 

[Bill33525]

Went out today to try to recreate the thumping experience, however, no joy. After some research the Tesla forum detailed many Tesla drivers having similar issues with the foam liner coming unglued and bunched up causing an unbalanced condition. Updates to follow.

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