Solution to pressure buffeting issue in some cars
A huge thanks to DrComputer on the Tesla Motors Club forum for posting his solution to this issue. My car also has exhibited a strange low pressure buffeting even when all the windows were open and the sunroof was open. I'm going to try this fix tonight and see if it solves the issue.
Originally Posted by UMD86
The analyst from Cars.com experienced the same thing I did when I test drove the Performance Model. Below is his article. Has anyone ever experienced the same thing? Does anyone know why this happens?
I noticed it in my other cars when I lower the rear windows only. It feels like your ears are clapping. I have to lower the other windows to prevent it. With the Model Perf. "S" it happens when ALL of the windows are up.
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The ride quality is also firmer than I expected from a sizable five-seater; however, the Signature Performance I drove has 21-inch wheels; the lineup starts with 19-inchers. There was also a troublesome low-frequency resonance — a vibration felt more than heard — that was most pronounced on grooved-concrete interstate but which was also detectable at other times. It felt a bit like the pressure buffeting that sometimes happens when you drive with a moonroof open too far, but not accompanied by the higher frequency wind turbulence. I and a passenger — and another editor driving separately — found it terribly irritating.
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This is concern for me. I will have to test drive both models before I finalize my order. I hope it's nothing major - I like the interior headroom of the perf. model.
(POST FROM DrComputer on the TMC Forum - This was one of the first problems I reported to Tesla. On my drive home from the factory I too noticed the horrible "pressure buffeting" when all of the windows and sunroof were closed. I tried several experiments to see if I lowered the windows slightly or opened the sunroof if it would go away. It didn't. After discussing it with the LA service center and them with corporate they determined this is a known issue and is actually caused by rear hatch. If you open the rear hatch you will find two thumb screw type rubber dampers on each side of the hatch by the edge (not the solid plates they press against on the car itself). If the screws are not far enough out the hatch acts as a large speaker bouncing up and down as you drive over uneven roads creating this uncomfortable pressure feeling. Adjust them out far enough so the hatch closes tightly but not too far where the automatic closer will not shut because there is too much pressure. This adjustment, in combination with the rear parcel shelf to absorb vibration, greatly reduces the pressure buffeting problem
Originally Posted by UMD86
The analyst from Cars.com experienced the same thing I did when I test drove the Performance Model. Below is his article. Has anyone ever experienced the same thing? Does anyone know why this happens?
I noticed it in my other cars when I lower the rear windows only. It feels like your ears are clapping. I have to lower the other windows to prevent it. With the Model Perf. "S" it happens when ALL of the windows are up.
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The ride quality is also firmer than I expected from a sizable five-seater; however, the Signature Performance I drove has 21-inch wheels; the lineup starts with 19-inchers. There was also a troublesome low-frequency resonance — a vibration felt more than heard — that was most pronounced on grooved-concrete interstate but which was also detectable at other times. It felt a bit like the pressure buffeting that sometimes happens when you drive with a moonroof open too far, but not accompanied by the higher frequency wind turbulence. I and a passenger — and another editor driving separately — found it terribly irritating.
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This is concern for me. I will have to test drive both models before I finalize my order. I hope it's nothing major - I like the interior headroom of the perf. model.
(POST FROM DrComputer on the TMC Forum - This was one of the first problems I reported to Tesla. On my drive home from the factory I too noticed the horrible "pressure buffeting" when all of the windows and sunroof were closed. I tried several experiments to see if I lowered the windows slightly or opened the sunroof if it would go away. It didn't. After discussing it with the LA service center and them with corporate they determined this is a known issue and is actually caused by rear hatch. If you open the rear hatch you will find two thumb screw type rubber dampers on each side of the hatch by the edge (not the solid plates they press against on the car itself). If the screws are not far enough out the hatch acts as a large speaker bouncing up and down as you drive over uneven roads creating this uncomfortable pressure feeling. Adjust them out far enough so the hatch closes tightly but not too far where the automatic closer will not shut because there is too much pressure. This adjustment, in combination with the rear parcel shelf to absorb vibration, greatly reduces the pressure buffeting problem
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The two rubber screws on each side of the lift gate in my car were screwed all the way in (thus giving no extra support to the hatch over bumps in the road). I ended up loosening the screws (turned the screws to the left or counter-clockwise) to extend the screws further. I think in my case, I extended both screws about 1/4 inch or 3/8th of an inch. I extended them just to the point where the automatic lift gate wouldn't open back up. It makes the lift gate very snug against the rubber stops on the frame. I may experiment a bit to see how much I can retract the screws back into the lift gate to see where the threshold of buffeting is.
I don't have a rear parcel shelf, so I think once I get that delivered from my due bill, that may help reduce the low frequency noise even more. But I'm now a happy camper!
So I went out and played with the rubber screws a bit. It seems that my screws were set pretty far out and I could only turn them about a quarter turn before the hatch was not able to automatically close. It seems to have alleviated the buffeting problem <b>slightly</b> (or it could be that I'm more used to the buffeting now). Hopefully, the parcel shelf will help the situation, because this is very annoying.
(I posted this on the Tesla Motors club forum as well)...
Also an update for everyone on the setting of the rubber shims to resolve the pressure buffeting issue: I felt that after adjusting the rubber shims on my hatch that the hatch was putting a lot of pressure on the locking mechanism. I discovered that the plastic platforms that the shims sit upon when they close are also adjustable. I found that if I raised (extended them towards the moveable hatch) those a bit and lowered (retracted into the moveable hatch) the rubber shims, that helped with the pressure on the latch while keeping the buffeting with the windows closed issue minimized. It does take a bit of adjusting to get everything level and balanced when the hatch closes, so if you try the fix and it doesn't seem to completely resolve your issue, keep adjusting all 4 screws to get the hatch to close in balance with even pressure all around.
I believe once you get an even pressure about all four contact points, the buffeting is minimized as much as possible with that adjustment. I could see why they might rush that part of the QC at Tesla if they are trying to delivery cars fast. It could take quite a bit of trial and error to get it completely right.
I also noticed that my fix has reduced the funny sound I sometimes get with the HVAC system turned on at a medium range fan speed. It's the same pressure buffeting, so I think because the car is so tightly sealed, when the fan runs at a certain speed, it is causing the hatch to move in and out slightly as air is drawn into the car.
Thrilled to find this thread as I feared I was the only one. I will adjust bumpers today and report back.
That would be helpful and much appreciated.
I haven't posted a video to YouTube before, but I'll see if I can figure it out and post the method to adjust the rubber shims and the plastic caps on the rear hatch.
The good news is that the combination of the parcel shelf in place and the adjustments of the rear hatch shims was able to reduce the pressure buffeting in my car to the point where I consider it solved!
But the one thing it hasn't solved is if you set the HVAC system to push air to the windshield vent and to the vents in the dash and set the fan speed at a certain setting (can't remember exactly, but I think it's a speed above 4 or so) then there is a buffeting that will happen in the cabin. That particular set of conditions is rare to have in my car, so it's not a problem. When it happens, it will only happen for a short period of time and I can live with it because at least I have control over it and can turn the vents off or turn the fan speed down.
I can confirm with certainty that Brian H is 100% on the ball as the pressure buffeting stops the moment the trunk is opened both when I am in park or in motion. Not sure what to do next short of going in for service or at least waiting for delivery of my shelf.
Then I made sure both are tight against their respective stoppers by putting a long string or long piece of paper on the dampener, then close the trunk. If the string or paper can't be pulled out, they are tight enough. This should take some guess work out.
Now the trunk rest firmly, and the buffeting is gone. Drove the car in some nasty roads in Camden NJ today, no buffeting!
jlamano, thanks for the info about adjusting the latch, striker and stops, that's good to know as well.
The benefit of using a string or paper to test for tightness of the dampeners should help prevent over or under adjusting (raised the dampeners too high or not high enough).
Let me know how it works out for you. Hopefully you don't need to bring it in to the service center for the full adjustment.