TOEd
Posts: 73
Joined: Sat Mar 05, 2016 5:15 am
Location: Toronto Ontario Canada

Buzzing from REx cooling fan

Mon Dec 04, 2017 8:32 am

Has anyone had a REx cooling fan buzz? After 38,000 km (10,000 km on REx) the cooling fan has started to emit an annoying buzzing sound. I haven't crawled under there yet so it may be an easy fix. I hate the idea of bringing it to the dealer because it will waste half a day and last time they spun the driver mirror 180 degrees from normal when they took it through car wash. Their fix was to manually crank the mirror back into position and assure me this was normal and that no damage was done.

tobiassej
Posts: 17
Joined: Sun Aug 09, 2015 6:14 am
Location: Denmark

Re: Buzzing from REx cooling fan

Sat Jan 06, 2018 1:24 pm

I might have the same issue. However I have a BEV (not REX) and it's winter here (Denmark, 0-5 Celcius).
I get a rumbling noise from both front and back of the car. The rumbling sound is gone when I turn heating off.
It's especially a problem when preheating the car or standing still.
People ask me if the car has a problem.
I'm taking it to the dealer next week but they had no idea ahead of the service.

Anyone has a hunch?

jadnashuanh
Posts: 3597
Joined: Thu May 22, 2014 2:07 pm
Location: Nashua, NH USA

Re: Buzzing from REx cooling fan

Sat Jan 06, 2018 7:43 pm

The heat pump can get loud. Not sure that is an indication of a problem. Not sure how to separate that noise from the coolant circulator in the batteries.
Jim DeBruycker
2011 535i x-drive GT, 2014 i3 BEV

RockSalt
Posts: 1
Joined: Fri Jan 12, 2018 12:28 pm

Re: Buzzing from REx cooling fan

Fri Jan 12, 2018 12:35 pm

I have the same issue reported by tobiassej, and just scheduled an appt for next week. When driving over 30mph with the heating on, after several minutes a loud buzzing noise like a rattling bathroom fan starts. Each time the vehicle slows below 30mph to stop, the noise subsides. when the vehicle speeds back up, the noise returns. If while driving with the heat on and the noise present, I shut off the heating, the noise goes away. If I then turn the heat back on, after a minute or less the noise returns. Based on other reading I suspect this is the compressor for the coolant system that cools the batteries, which would presumably be under load when driving over 30mph with the heat on. However it does not make sense that the system would run continuously as it does when driving with the heat on or be that noisy.

jadnashuanh
Posts: 3597
Joined: Thu May 22, 2014 2:07 pm
Location: Nashua, NH USA

Re: Buzzing from REx cooling fan

Fri Jan 12, 2018 5:03 pm

The REx, unlike the BEV, does not have a heat pump. The BEV's heat pump is a bit noisy from the outside, but not significant inside the vehicle. This time of year (at least in the northern hemisphere), excessive heat is probably not an issue. I think the batteries, if they did need cooling, could just use the pump and radiator.
Jim DeBruycker
2011 535i x-drive GT, 2014 i3 BEV

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