[n55n]

Hi everyone, after doing a coolant flush on my 2015 435i (60k miles) this loud fan like noise coming from right around the reservoir started. Temperature is good after monitoring with no leaks found. Anyone know what the noise could be?

[BashShah]

Can you tell us which Coolant is in there now?
If BMW Coolant, is it 50/50 Mix.
Did you do a Coolant Bleed Procedure? (Look it up)

If all the Above is good?
then Is the Fan making Noise like what?
or is just a HIGH Fan Speed Noise.

If High Speed Fan Noise, then most Likely it may be the Thermostat or Water Pump.

[n55n]

Originally Posted by BashShah

Can you tell us which Coolant is in there now?
If BMW Coolant, is it 50/50 Mix.
Did you do a Coolant Bleed Procedure? (Look it up)

If all the Above is good?
then Is the Fan making Noise like what?
or is just a HIGH Fan Speed Noise.

If High Speed Fan Noise, then most Likely it may be the Thermostat or Water Pump.

I got it straight from dealership and yes I mixed it. Also did the bleed procedure. It’s not all the time which is weird but it sounds like a fan with fast clicking as well. The sound is coming somewhere next to the hose right above the reservoir. (Wish I can send a video thru app)

[BashShah]

Dealership?
Ok, why not go back there and tell them this?
They should be diagnosing this as it occured right after a coolant flush from the them.