Howling,wheezy sound when cold

Yes my replacement engine high frequency whines for several minutes in the same cold conditions, my original did not.

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Engine?

 

I'd put my money on oil cavitation, a common effect of excessively thick oil. Cleary that's not affected by a motor change but it might be a different noise than what @apu is referring to.

Here's your chance to kill two birds with one stone:
Change the gear reducer oil and use Redline MT-LV. The Redline is a high-quality synthetic which may behave better at -15°C as the pour-point is -60°C. This will also clear out all the metal that's circulating in the old oil because I expect they didn't install a magnetic drain plug, as with the Kona. If you can access Motul or Fuchs oils you might find something equivalent or better, perhaps even an ATF designed for low temperatures. ATFs used in transaxles are suitable. The OEM oil may be a mineral type and behave poorly at low temps.

Long ago I encountered an industrial gearbox at a worksite that increased the speed of a 3000 hp electric motor from 3,000 to 25,000 rpm. For the first 10 minutes it sounded like a wood chipper. I was told by the customer, a helicopter gearbox expert, that it was due to oil cavitation.

 

The only "howling wheezy" sounds I hear when it's cold come from the driver's seat.

 

If the sound is only present at higher speeds (e.g. above a crawl) or changes with speed, I'd also suspect the gearbox and cold oil.

If it's present even when sitting still, then it's definitely not the gearbox... it might be a pump? Not sure if the battery heater works by direct heating elements or by warming and circulating the coolant fluid. If you have a heat pump for the cabin it might also be related to that; the compressor or the fan. If possible, leave the car plugged in and use the cabin preheat feature to see if that makes a difference.

 

Basically this:

 

I expeienced similar issue with my 2019 Kona electric this past winter. When the tempearatur goes below -10C and at certain speed (not necessarilyat high speed) I would hear the high pitch wheezy sound. Once I move to higher speed then the nosie goes away. The noise did nto go away enen when the car is warmed up. I did not experience this in the past 2 winters but this year the noise was apparent.

 

While my noisy drivetrain woes are well documented in other threads I can confirm that this year, the "normal/abnormal" noise from the drive train became extremely loud and harmonic during our -30° weather.

 

Thaks for the feedback, in my case it ocurred below -10C and its strange that I have experienced such low temperature in the past years but this is the first year that this high pitch sound occurs. Still not sure if it is coming from the engine or gearbox and if it is something I should be conerned about

 

My noises didn't show up until 2 3/4 years of ownership. They got loud and concerning very quickly thereafter. If this is the first you've noticed noise in certain conditions you'd do well to keep your ears open for progression in the coming weeks and months.

 

Thank you. My Kona just turned 3 years old in Feb 2022 and it is just before that when I first noticed the noise. Now Winter is over will continuue to keep my ears open during warmer weather to see if it occurs at warmer temperature and for sure will see how it goes next winter

 

Our cars are exactly the same age. I'm not saying yours is going to track mine exactly but it's an interesting pattern.

 

Yes the pattern is interesting similar...