2021: Low Frequency Vibration

[Ampre Sand]

Did some exploration yesterday with the frunk liner removed. As far as I can tell, this low frequency tone is a sympathetic vibration in the cabin as the heat pump spins up through a certain RPM range. It would guess it's a pesky NVH issue that is a) harmless, and b) what's left over after really making the pump incredibly quiet (it really is). Stuff like this is like whack-a-mole to the engineering team. Given the sound is brief, I'd bet they even know about it and intentionally keep the pump's time in that RPM range as brief as feasible.

Cases in point: my neighbor's pool pump goes into high speed cleaning mode every morning at about 10AM. He can't hear it, but the frequency it runs through happens to match some resonance in my upstairs bedroom. Took me a while to figure out the source of the vibration. Similarly, the washing machine at the other end of the house causes my living room window to vibrate like there's an earthquake happening. No other vibrations felt anywhere - it's just a resonance that happens to match.

As an aside, the HVAC system under the frunk liner is a startlingly beautiful bit of engineering. I'm sure it will continue to evolve, as well.

 

[Ampre Sand]

Did some more experimenting. Now I’m not sure it’s the heat pump compressor. I had A/C disabled and was able to get the rumble just by adjusting the temperature to LO then back up to 70F with no other changes. The compressor wasn’t running, but heat was coming out the vents on command.

Perhaps it is the system spinning up a circulator pump or something to do with the Octovalve. Might also be the system “juicing” the traction motor windings to create some heat. Hmm.

 

[clerks]

You have to really pay attention to notice it.

Mike

On mine there is no way of missing it.

 

[lolder]

It's not the heat pump, it's the condenser cooling fan. My July 2018 M3 LR RWD was completely silent the first month and then the periodic vibration started. A mobile tech and I diagnosed it as the cooling fan, not the compressor. They have balance weights on them and it was thrown off. Last year Tesla replaced the cooling fan under warranty. The old fan had a marking on the blade where the weight had been. The new fan was quiet for a month and then it too threw the weight and the vibration is back. It only occurs at one rpm and since it's computer controlled it's hard to demonstrate. Basically it vibrates at home and not the Tesla Service center. I guess their glue is not good enough and since it's occurring on new cars they may have given up balancing them. When they changed the fan I should have asked them to add some more glue/epoxy/etc.

 

[MikeyC]

It's not the heat pump, it's the condenser cooling fan. My July 2018 M3 LR RWD was completely silent the first month and then the periodic vibration started. A mobile tech and I diagnosed it as the cooling fan, not the compressor. They have balance weights on them and it was thrown off. Last year Tesla replaced the cooling fan under warranty. The old fan had a marking on the blade where the weight had been. The new fan was quiet for a month and then it too threw the weight and the vibration is back. It only occurs at one rpm and since it's computer controlled it's hard to demonstrate. Basically it vibrates at home and not the Tesla Service center. I guess their glue is not good enough and since it's occurring on new cars they may have given up balancing them. When they changed the fan I should have asked them to add some more glue/epoxy/etc.

Why are they adding weight to the light blade(s)? Take weight off the heavy ones, like you do when balancing props on a drone! Sand down the heavy blade(s) a little.

Mike

 

[CSMoore]

Noticed this today: when standing still, there is a low frequency vibration (probably ≤ 40Hz) lasting about 2 seconds, then cycling through every 5-10 seconds thereafter. It seems to originate at a structurally-sensitive point that vibrates the frame of the car. Reminded me a bit of a sub-woofer in a car parked next to me.

On another forum it was speculated that this is the heat pump in action.

Any comments?

P.S: AC was off when this happened, so must be something else

Picked up my M3 LR and heard this while waiting in the car for delivery. Hopefully they can dampen it somehow.

 

[lolder]

Why are they adding weight to the light blade(s)? Take weight off the heavy ones, like you do when balancing props on a drone! Sand down the heavy blade(s) a little.

Mike

Sanding would be labor and time intensive. Most if not all rotary devices are balanced in a few seconds on a computer device that tells you exactly how much and where to put weights just like car wheels. Of course they should not come off. I have balanced propellers on Quad copters by sanding but it takes a long time.

 

[ParHunter]

So is the consensus now that it is a problem with the condenser cooling fan and should be looked at or is it the heat pump or is it maybe both?
How many people with a pre 2021 model have it and how many with a 2021 model?
If there are only a couple of people who have it with a pre 2021 model but nearly everyone with a 2021 model then it could be two different problems with a similar effect.

 

[variable]

My 2021 is in service for this I think. It was in service last week for a burning smell from the HVAC. Whatever they did, now there is an extreme, short vibration that happens intermittently, usually after the car has been sitting for a little while. Seems to be tied to the HVAC.

I'm also on my 3rd heat pump compressor. The last time it was replaced as part of an "engineering study" per the invoice?

Sounds like a BVVVVZZZ for maybe a second. It's extremely loud and vibrates the whole car. SC acknowledged they can hear it but aren't sure the source.

I would probably ask for a buy back of the car if I didn't need it in a month for a cross country trip to my new job, and cars don't seem to exist any more due to the silicon shortage. Adding up all the issues I've had with ICE cars over 20 years wouldn't equal the problems I've had with this car in just five months.

 

[TBrownTX]

I really just don’t find it to be that big a deal.

Tim

 

[variable]

I really just don’t find it to be that big a deal.

Tim

You may change your mind when it sounds like your car will explode. That's how bad the latest issue is on my car. If the whole car is vibrating, that means the source is likely going to vibrate itself out of its mount or cause other mechanical issues down the road.

 

[TBrownTX]

You may change your mind when it sounds like your car will explode. That's how bad the latest issue is on my car. If the whole car is vibrating, that means the source is likely going to vibrate itself out of its mount or cause other mechanical issues down the road.

My last car was an ICE vehicle, literally little explosions going on under the hood ALL THE TIME. It was loud, vibrated at stop lights, and got really hot too.

Maybe yours is worse than mine, or I don’t notice it over the blaring radio, but I still don’t think it’s a big problem. If they release a TSB down the road I would not bother.

Tim

 

[variable]

My last car was an ICE vehicle, literally little explosions going on under the hood ALL THE TIME. It was loud, vibrated at stop lights, and got really hot too.

Maybe yours is worse than mine, or I don’t notice it over the blaring radio, but I still don’t think it’s a big problem. If they release a TSB down the road I would not bother.

Tim

It always fascinates me on any of the Telsa forums how some people are so dismissive of reported issues. My last car was a VW GTI that has zero issues for the four years I owned it. Not a single one. My M3 on the other hand has had more issues in 3000 miles of ownership and spent more time in the shop than my past 20 years of cars combined. That's impressive. If I didn't need this car for a cross country road trip to my new home and job out in California, I would lemon law it in a second. I'm glad your car is fine Tim, but mine most definitely is not.

Anyway, SC clearly found an issue with mine here because they had to call Engineering, and Engineering said to replace the Liquid Cooled Condenser Expansion Valve as it is closed shut, as well as the compressor (this is now compressor #3). That's very clearly an issue in a heat pump that requires all the valves to be opening properly, and no surprise that there is a hugely audible BRRRMMMP and a corresponding vibration because it's not opening.

It also begs the question of how much training the SCs have been given on the new heat pump systems.

 

[Amped412]

It always fascinates me on any of the Telsa forums how some people are so dismissive of reported issues. My last car was a VW GTI that has zero issues for the four years I owned it. Not a single one. My M3 on the other hand has had more issues in 3000 miles of ownership and spent more time in the shop than my past 20 years of cars combined. That's impressive. If I didn't need this car for a cross country road trip to my new home and job out in California, I would lemon law it in a second. I'm glad your car is fine Tim, but mine most definitely is not.

Anyway, SC clearly found an issue with mine here because they had to call Engineering, and Engineering said to replace the Liquid Cooled Condenser Expansion Valve as it is closed shut, as well as the compressor (this is now compressor #3). That's very clearly an issue in a heat pump that requires all the valves to be opening properly, and no surprise that there is a hugely audible BRRRMMMP and a corresponding vibration because it's not opening.

It also begs the question of how much training the SCs have been given on the new heat pump systems.

I have a SR+ that makes a low rumble vibration but nothing like what you're describing. It sounds like you just got bad luck with a bad part. Every complex product has at least a 1% chance of failure right off the production line. Sounds like you used up all of your luck with the GTI. I have some buddies that have owned GTI's and they've had nothing but issues and have sold them by now. I hope the SC can fix it for you and I hope you have better luck in the future.

 

[Gasaraki]

It's the heat pump. The heat pump and octovalve is used to heat and cool the batteries and cabin in the 2021s.

 

[variable]

I have a SR+ that makes a low rumble vibration but nothing like what you're describing. It sounds like you just got bad luck with a bad part. Every complex product has at least a 1% chance of failure right off the production line. Sounds like you used up all of your luck with the GTI. I have some buddies that have owned GTI's and they've had nothing but issues and have sold them by now. I hope the SC can fix it for you and I hope you have better luck in the future.

I think I got the M3 that was built by drunken robots and a half blind QC person, to be honest. Half the car was fine for panel fitment, the other half had a ton of issues.

What's concerning is it seems like they didn't work out the kinks with the heat pump system. Between the recall for the sensors and now the issues that I'm experiencing, I suspect there wasn't thorough testing on the various components and overall design to ensure it's not going to blow up down the road.

If anyone cares, here are the parts that Tesla had to order for the latest fix (I assume there are additional parts based on what they described, they just had to order these because they weren't in the shop):

1. Service Kit, SM EXV Core, Heat Pump
   Part #: 1603591-00-A
   Order Date: May 17, 2021
2. Service Kit, SM EXV Coil, Heat Pump
   Part #: 1603592-00-A
   Order Date: May 17, 2021

 

[variable]

I think I got the M3 that was built by drunken robots and a half blind QC person, to be honest. Half the car was fine for panel fitment, the other half had a ton of issues.

What's concerning is it seems like they didn't work out the kinks with the heat pump system. Between the recall for the sensors and now the issues that I'm experiencing, I suspect there wasn't thorough testing on the various components and overall design to ensure it's not going to blow up down the road.

If anyone cares, here are the parts that Tesla had to order for the latest fix (I assume there are additional parts based on what they described, they just had to order these because they weren't in the shop):

1. Service Kit, SM EXV Core, Heat Pump
   Part #: 1603591-00-A
   Order Date: May 17, 2021
2. Service Kit, SM EXV Coil, Heat Pump
   Part #: 1603592-00-A
   Order Date: May 17, 2021

Quick update, got the car back today. It was a pretty quick fix once the parts came in--they got them yesterday afternoon and the car was ready to pick up this morning.

So far the issue seems to be gone and the AC definitely feels like it's blowing colder than it was before. Heat is hot as well. No more expodey sounds when HVAC is turned on, just the typical heatpump and fan noises. Overall it's pretty quiet and hopefully this fix lasts.

 

[Gvardaman]

We haven’t had a single issue with our M3, so far at least!
I’ve also had good luck with VWs and BMWs, an Isuzu and bad luck with a Mini Copper S and a Subaru Forester. I think it is just luck, driving conditions and so many small random factors in many cases.
Sorry you have had bad luck With yours. I hope this is finally “the” fix and good luck with the move and new job.
Tim: nice weathering on your R2!