Easy and effective low frequency fix

[salix]

So yesterday my wife drove the Y by herself for the first time and came back complaining about the boominess over any road imperfection (and in Minnesota pretty much every square inch of pavement that's over one winter old is cracked and potholed). On earlier drives as a passenger she said it didn't bother her, but now it is starting to get to her too.

I spent a good 45 minutes squeezed into the trunk last night adjusting the hatch stops with the paper technique, ensuring that all contact solidly, but so far nothing has helped much.

I haven't yet had a chance to get the tubing or PVC caps to try the rigid stops that @MY-Y advocates BUT I have one major cause for doubt, which is that just sitting in the trunk, tapping on the center of the glass of the rear hatch, I hear it ring out like a drum with that annoying low frequency boom. It seems like Tesla has just inadvertently designed to function like a drum tuned to that low pitch. So rigid stops, while they might prevent some hatch movement over bumps, seem like they are probably MORE likely to excite that "drum"...

We've decided to give the car a few more weeks (and I'll try out the rigid stops), but are prepared to sell. Carvana will give us slightly more than we paid for it to buy it from us right now, so that's reassuring.

 

[salix]

The frustrating part is that we like the car otherwise, we HAVE it, and really don't want to buy another ICE, but other EVs are both hard to obtain and lack the ability to drive long distances due to the lack of a viable charger network.

 

[ilovecoffee]

So yesterday my wife drove the Y by herself for the first time and came back complaining about the boominess over any road imperfection (and in Minnesota pretty much every square inch of pavement that's over one winter old is cracked and potholed). On earlier drives as a passenger she said it didn't bother her, but now it is starting to get to her too.

I spent a good 45 minutes squeezed into the trunk last night adjusting the hatch stops with the paper technique, ensuring that all contact solidly, but so far nothing has helped much.

I haven't yet had a chance to get the tubing or PVC caps to try the rigid stops that @MY-Y advocates BUT I have one major cause for doubt, which is that just sitting in the trunk, tapping on the center of the glass of the rear hatch, I hear it ring out like a drum with that annoying low frequency boom. It seems like Tesla has just inadvertently designed to function like a drum tuned to that low pitch. So rigid stops, while they might prevent some hatch movement over bumps, seem like they are probably MORE likely to excite that "drum"...

We've decided to give the car a few more weeks (and I'll try out the rigid stops), but are prepared to sell. Carvana will give us slightly more than we paid for it to buy it from us right now, so that's reassuring.

Interesting note about the rear glass.

It's crossed my mind to put a thin layer of butyl around the edges of the glass behind the plastic trim in case there's resonance there.

I haven't had the chance to ride in the trunk. Did you put your ear up near the glass? Could you sense anything? Lots of panels will make a low frequency when tapped.

 

[salix]

I haven't had the chance to ride in the trunk. Did you put your ear up near the glass? Could you sense anything? Lots of panels will make a low frequency when tapped.

To clarify I wasn’t riding in the trunk, just in there to adjust the stops while parked. The lower stops seem like you need to be inside to pull the paper without the gasket interfering.

And you’re right, just because something resonates doesn’t mean it’s the cause - the cover for the lower trunk area also resonates pretty well when struck but removing it has no effect on the booming so I’m guessing it’s not the culprit.

 

[MY-Y]

You can use the same method I used to find the cause. Use the spectroid app (or an iPhone equivalent) when driving to find the exact frequency that is booming. Then, when parked, run spectroid in the same location with someone thumping the car with their hand to find the surface that resonates at that frequency. (Not hard enough to dent it of course.) That is most likely the culprit. For me, it was the outer bump stop flex. The inner ones (the bottom center of the window) resonated a few Hz higher.

 

[MyEarHurts]

As for putting butyl around the edges I kind of did that. If you open the tail gate and look on the back of the glass roof, there is space to put some pieces in double layer. I also put some on the front. I can't say I noticed a difference. I think it's all in the hatch and the inner quarter panels cause it only happens on bumps.

 

[Noflash]

it was the outer bump stop flex

What is this?

 

[ahhlun]

Perhaps the tech is someone that is sensitive to these sounds. That doesn't mean it bothers everyone.

Never said it bothers everyone, while you came in calling my post "nonsense"

 

[MY-Y]

What is this?

See my post that started this thread.

 

[Noflash]

See my post that started this thread.

Oh, I associate "bump stop" with the suspension.

 

[jgrgnt]

My 3/2022 MYP has the pressure buffering and booming. So far, I’ve tried the paper-pull test on all four bump stops and made adjustments where necessary, but that seemed to make very little difference. My hatch was slightly crooked at delivery, so today I loosened the two bolts on the upper left hinge and got everything in alignment. Was hoping that might improve the sound situation, but no luck. Tomorrow I’m going to try the solid bump stops described in this thread.

 

[salix]

Got some 5/16" OD vinyl tubing and some PVC fittings for rigid bump stops, although realizing that making the rigid bumps tops is less trivial than I originally thought, so haven't tackled it yet. Worried that the tubing install may damage the hatch gasket (still have an eye on selling the car).

 

[Noflash]

Got some 5/16" OD vinyl tubing and some PVC fittings for rigid bump stops, although realizing that making the rigid bumps tops is less trivial than I originally thought, so haven't tackled it yet. Worried that the tubing install may damage the hatch gasket (still have an eye on selling the car).

I tried 3 different sizes of tubing and the gasket is a bit hacked. I also noticed water in the gasket the last time I took tubing out. Considering a quote on replacement.

 

[ilovecoffee]

I tried 3 different sizes of tubing and the gasket is a bit hacked. I also noticed water in the gasket the last time I took tubing out. Considering a quote on replacement.

What?! Did you butcher it??? What size did you end up putting in there?

Sure I've got one slightly larger hole on top and one on the bottom. I've taken it through countless car washes...are you sure maybe your hatch clearance from your stops is not too big?

 

[Noflash]

What?! Did you butcher it??? What size did you end up putting in there?

Sure I've got one slightly larger hole on top and one on the bottom. I've taken it through countless car washes...are you sure maybe your hatch clearance from your stops is not too big?

Maybe? The hole at the top did tear a bit. It may be a symptom of my carwash too. I get water in the frunk.

 

[ilovecoffee]

Maybe? The hole at the top did tear a bit. It may be a symptom of my carwash too. I get water in the frunk.

So for water to get into that gasket, it's unusual because it is raised quite a bit off any of the normal places where water is supposed to go.

For reference this is the top middle gasket hole (this is where I fed in the vinyl tube in 2 directions so it's a bit bigger)

bottom gasket hole:

You could theoretically use something like this to close back up the hole a little bit:

Permatex 59203 Black RTV Silicone Adhesive Sealant 16BR, 80ml : Amazon.ca: Automotive

Permatex 59203 Black RTV Silicone Adhesive Sealant 16BR, 80ml : Amazon.ca: Automotive

www.amazon.ca

But I think if water is getting in there, you should re-look at your hatch stop adjustments...something isn't right.

 

[PecuniaNonOlet]

I tore up the gasket installing my vinyl tubing because I'm a caveman. Still no leaks.

 

[Noflash]

I have a hole on the lower-side gasket and the second time I took the tubing out I noticed water in the tubing. The touchless carwash I go to sprays pretty forcefully from the side. I think some water got in the gasket hole and just went down the tube. The third time I removed tubing I didn't notice any water. I have no tubing in now as I didn't notice any benefit and wanted to try the hatch stop caps without the tubing. I don't have high hopes, but thought it was worth a shot. If I ever take my car in for service I'll ask how much to replace.

On another note, I am about to buy some 18" rims and tires. Going down to 18" will provide a smoother ride, Vedestein Quatrac Pros will help even more, and I'm going with an oversized tire of 255/55-18 for maximum cushion. Of course Tirerack only has 1 tire in stock. This may delay my plan.

P.S. Also, called the local Kia and Hyundai dealerships to ask about the EV6 and Ioniq 5. Both are being bought sight-unseen before they even get to the dealerships. Not a lot of options out there, so I am trying to fix what I have.

 

[MY-Y]

I have a hole on the lower-side gasket and the second time I took the tubing out I noticed water in the tubing. The touchless carwash I go to sprays pretty forcefully from the side. I think some water got in the gasket hole and just went down the tube. The third time I removed tubing I didn't notice any water. I have no tubing in now as I didn't notice any benefit and wanted to try the hatch stop caps without the tubing. I don't have high hopes, but thought it was worth a shot. If I ever take my car in for service I'll ask how much to replace.

On another note, I am about to buy some 18" rims and tires. Going down to 18" will provide a smoother ride, Vedestein Quatrac Pros will help even more, and I'm going with an oversized tire of 255/55-18 for maximum cushion. Of course Tirerack only has 1 tire in stock. This may delay my plan.

P.S. Also, called the local Kia and Hyundai dealerships to ask about the EV6 and Ioniq 5. Both are being bought sight-unseen before they even get to the dealerships. Not a lot of options out there, so I am trying to fix what I have.

Are you going down to an 8.5" rim? That shoud help too. The stock 9.5" width is a bit too wide for the tire you selected. With the increased air volume, you should be able to drop the pressure too.

 

[Noflash]

Are you going down to an 8.5" rim? That shoud help too. The stock 9.5" width is a bit too wide for the tire you selected. With the increased air volume, you should be able to drop the pressure too.

It's an 18x8.0". Any issue there?