Heat pump vibrations and noise

[Sandro]

Hey all!

My Enyaq got back from service because the heat pump made vibrations that you can feel through the steering wheel, front panels, and the arm rest.

They have now changed the heat pump but now still I have the same issues. As soon as you go up over 21 C heating you can clearly hear a lot of humming from the pump and also vibrations.

I guess this could be normal? At this point I am not sure and this really annoys me to a point that I am thinking of selling the car . They have changed it and it is the same, either I got another bad pump or this is as it should be perhaps?

Do you have the same experience with your heat pump or are yours silent?

Any help would be appreciated!

[BioHzrd]

Does the noise/vibration stop once your set temperature is reached ?

[Sandro]

Yes it does, you can really hear and feel it working. The higher temperature and fan speed you choose the harder the pump works. Once the pump turns off you really feel all the vibrations stopping.

[RichR]

Can't say I've noticed it on mine. It's just an electric compressor after all, and it's mounted well away from the passenger compartment. Though to be fair, I don't think I've ever set the heating higher than 20C (usually I have it on 18C).

[Sandro]

Can you give it a try? Set it to say 23 C and see if you feel vibrations in the car, it is quite hard to miss...

[RichR]

Ok - let the car warm up to 18C on auto, fans stopped to low speed as it hot there. Doing about 50mph. Increased to 28C. Fans got faster (gently) and hotter air coming out round my feet.

No noticeable increase in noise other than fans which aren’t that noticeable unless listening specifically for them.

Was your battery hot or cold when you get the noise?

[Sandro]

Thanks for trying! Funny thing is that sometimes the pump won't kick in and start working, and sometimes it does. Also, sometimes the pump won't work at 28 C but starts working if you lower the temp to 21-22C. Your car is equipped with the pump I assume?

Battery both warm and cold, really dosen't matter I'm afraid.

You hear the pump spin up and gaining RPM and at a certain point the vibrations start, and I can fully control the amount of vibrations by simply turning the heating up and down.

[RichR]

Yes. You really shouldn’t be able to hear it at all, it’s only a small compressor mounted at the front of the car. Sure the noise isn’t from the radiator fan or something?

(Yes, I have a heat pump - as it says in the signature)

[chillyboy123]

I am guessing that cars without a heat pump, have a pump as well. For the battery cooling system.

I see it starting on OBD and can feel it start when I turn on the car sometimes.

It’s not annoying or something I can feel vibrate that bad though.

Have they replaced the correct faulty part ?

[RichR]

The heat pump compressor is almost exactly the same as the aircon compressor in the normal system. The difference is that the working fluid is R744 instead of R1234yf, and there are several additional valves and heat exchangers. The liquid coolant system is also almost the same - it’s this that the heat pump extracts heat from to heat the cabin. It’s just got a heat exchanger in it for that to happen.

See my ‘how the heat pump works’ thread