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A/C motor noise

Discussion in 'Model S: Driving Dynamics' started by modelx007, Feb 24, 2016.

  1. modelx007

    modelx007 Member

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    Have about 1000 miles and just today the fan motor is making loud noises that fluctuate like a motor. (Not normal ac fan noise which one expects with air flow noise). This is more like a vibration motor noise but certainly is the fan as when I turn off the ac it goes away and when the fan speed increases I can hear it get louder. Anyone else experience this?
     
  2. CHG-ON

    CHG-ON Still in love after all these miles

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    The AC compressor has to do double duty in the Tesla. It both cools the cabin and the battery pack coolant. So if it is warm, the car is hot and you have it set to a fairly low temperature, the compressor will sound like a plane taking off. And the compressor will run regardless of whether you have the AC on if the battery needs cooling. The fan noise you are hearing is part of the cooling system for the compressor and battery. It is different than the cabin fan. It concerned me a lot when I got my car. But now I am used to it.
     
  3. harry

    harry Member

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    At least for the earlier cars, there is a sound attenuating "blanket" that the SC can install which helps the noise somewhat. More recent cars may already have that (or some equivalent) installed at the factory.
     
  4. modelx007

    modelx007 Member

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    Ok but what is concerning a little is the fact it just started and the temperature hasn't changed nor conditions with the car. It was actually just sitting in car pool lane and 4 hours later sitting in my garage and heard the same loud motor noise. I'd be happier if this happened from day 1 vs 30 day mark..
     
  5. studiojon

    studiojon Member

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    Do you have the automatic pre-conditioning (beta) turned on? I found my car cooling itself in my garage at weird times due to this. It takes a couple of weeks for it to decide when to do it as well. Disable that and see if the problem goes away.
     
  6. Mike K

    Mike K Member

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    I think a lot of people assume the AC compressor is always cooling the battery but this isn't the case, at least from what I've seen. On a very hot 90 degree LA day it took about an hour of driving before AC came on to cool the battery and even then it was only on for a few minutes. My understanding is that during driving and normal charging the battery is primarily (as in almost all the time) cooled via passive cooling and actively cooled during supercharging.
     
  7. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    It's more active if you have range mode off. 90F is only hot in L.A. :)
     
  8. Mike K

    Mike K Member

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    Yeah "very hot" might have been a poor choice of words. 90 is just starting to heat up. :)

    My point is that even with range mode off you don't see it and when you do see it, it generally tells you it's actively cooling the battery and that interior AC might be less effective while it's doing this. You'll see a red warning bar at the top of the touchscreen with that message. The point being, it's almost never actively cooling, at least on the older cars.

    Fun fact, my salvage car came to me with no AC compressor activity. Driving the car in really hot weather had pretty much no affect on the battery. It wasn't until I parked for a few minutes and everything had a chance to heat soak that it then decided to try to actively cool. Even then it took 2 - 3 minutes of air flow over the front radiator to get rid of the message. It just wasn't an issue.
     
  9. CHG-ON

    CHG-ON Still in love after all these miles

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    I only hear the super loud compressor and fan when I start off in the car when it is warm/hot, after sitting in the sun. It doesn't get all that hot in Santa Cruz. Once the car is driving along and has good airflow, it goes away. I have heard the compressor running in my garage in the summer. But my garage doesn't get all that hot. Maybe 80-85 degrees at the most. So the battery seem to be getting warm enough for the compressor to go into mega-mode. It is alarming when it does.
     

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