[335dye]

UPDATE: Water Pump

I am looking for a little bit of help in diagnosing this noise coming from my wifes 2013 BMW X5 35i. I also have this posted in the X5 forums but figure there is more traffic here. When the A/C or heater is blowing, there is a loud buzzing noise coming from under the hood. It seems to be almost dead center on the front of the motor, right behind the radiator. It only makes the noise with air blowing. It goes away when you turn the air off. I did notice that if the heat or air is blowing and you shut the car off, the noise lasts about 5 more seconds. I did take a video and will try to upload it for reference. I had read a lot about the blower motor. Wouldn't I hear that under the glove compartment? It is pretty quiet inside of the vehicle. Thanks for any advice or insight before I end up paying the dealer to diagnose it.

[335dye]

Originally Posted by 335dye

I am looking for a little bit of help in diagnosing this noise coming from my wifes 2013 BMW X5. I also have this posted in the X5 forums but figure there is more traffic here. When the A/C or heater is blowing, there is a loud buzzing noise coming from under the hood. It seems to be almost dead center on the front of the motor, right behind the radiator. It only makes the noise with air blowing. It goes away when you turn the air off. I did notice that if the heat or air is blowing and you shut the car off, the noise lasts about 5 more seconds. I did take a video and will try to upload it for reference. Thanks for any advice or insight before I end up paying the dealer to diagnose it.

Video link

[e91Owner]

Sounds like the radiator fan to me. You can try unplugging it to see if the sound goes away with it running. The connector is on the passenger side of the fan. Should be pretty obvious.

If that solves the noise, the fan probably has something stuck in it that it's flapping against and you'd just need to remove it and clean it off. It's a pretty plug and play item after you remove the brace and is similar to removing the electric fans on e90s and e60s if you need a video.

[335dye]

Originally Posted by e91Owner

Sounds like the radiator fan to me. You can try unplugging it to see if the sound goes away with it running. The connector is on the passenger side of the fan. Should be pretty obvious.

If that solves the noise, the fan probably has something stuck in it that it's flapping against and you'd just need to remove it and clean it off. It's a pretty plug and play item after you remove the brace and is similar to removing the electric fans on e90s and e60s if you need a video.

I will try that out.

[Serf27]

Is this with the AC compressor on?

[335dye]

Originally Posted by Serf27

Is this with the AC compressor on?

Should be since the heat was blowing.

[e91Owner]

Originally Posted by 335dye

Should be since the heat was blowing.

It was off. You can see the switch in the video isn't illuminated.

[Serf27]

Originally Posted by e91Owner

It was off. You can see the switch in the video isn't illuminated.

Yea I re watched the video afterwards.

[335dye]

Originally Posted by e91Owner

It was off. You can see the switch in the video isn't illuminated.

I see what you are saying. I will check it out when I get home from work today

[335dye]

Originally Posted by Serf27

Is this with the AC compressor on?

I tried running the A/C and the heat and the noise happens in both settings. I noticed that if I start with the temperature at 60 degrees the noise is not present. But as I raise the temperature, a degree at a time, the noise starts and gets louder the higher the temperature.

[335dye]

Originally Posted by e91Owner

Sounds like the radiator fan to me. You can try unplugging it to see if the sound goes away with it running. The connector is on the passenger side of the fan. Should be pretty obvious.

If that solves the noise, the fan probably has something stuck in it that it's flapping against and you'd just need to remove it and clean it off. It's a pretty plug and play item after you remove the brace and is similar to removing the electric fans on e90s and e60s if you need a video.

Noise was still there after disconnecting the fan.

[335dye]

Another Video. After I let the noise run for probably 5 minutes while waiting for radiator fan to kick on, I noticed the noise and the air would start to get loud and then quiet. I also noticed that no air was actually blowing out of the vents except for the rear seats and the windshield defrosting vents.

[e91Owner]

Originally Posted by 335dye

Another Video. After I let the noise run for probably 5 minutes while waiting for radiator fan to kick on, I noticed the noise and the air would start to get loud and then quiet. I also noticed that no air was actually blowing out of the vents except for the rear seats and the windshield defrosting vents.

The revving of the electric fan when the car isn't in motion with AC on is pretty normal.

What I didn't hear in this video was that buzzing noise from the first one though.

[Serf27]

The AC was turned on in the second video too and the noise wasn’t there.

335dye,
Does the noise stop when the AC button is green?
Or was that a coincidence?

[335dye]

Originally Posted by Serf27

The AC was turned on in the second video too and the noise wasn’t there.

335dye,
Does the noise stop when the AC button is green?
Or was that a coincidence?

The noise is there when the AC is on. When it is at 60 degrees it goes away. But in the second video the noise would seem to disappear for a second when the pulsating or revving started. And then it would come back

[e91Owner]

If the blower fan isn't coming in then vents in the car, it's likely caused by the settings on your vent selection since you have that pressed.


For the main concern of the noise, if it comes and goes with the revving of the radiator fan with the AC on, the that would probably be something on your accessory belt. The fan surges would coincide with the cycling of the AC compressor. I would pull the codes to see if anything jumps out as an obvious criminal, but aside from that it's really just guessing here without having the car in front of me.

[335dye]

Just an update… ended being the water pump. I dropped it off at the dealer and he called saying it was the water pump and that it was covered under warranty. I guess in relation to the class action settlement. Luckily saved a nice chunk of change. Thanks for all of the input.