Has the strange noise emanating from your BMW’s air conditioning unit caught you off-guard? The emergence of such an odd noise could point to one of many different things going on with your vehicle’s AC unit– most obvious ones are discussed below. This post also sheds light on things that you can do to prevent such a trivial inconvenience from becoming a major repair.

Discussing Common Reasons

Reason #1- The belt; it’s loose

The serpentine belt is the reason why engine power gets conveyed to the AC compressor– and numerous other peripheral devices. Since it is made of rubber, it will get stretched over time. A stretched serpentine belt won’t be able to generate proper grip onto the compressor pulley– which is something that may contribute to the emergence of a strange squeaking or squealing noise.

Here’s what should be done if this is indeed the case;

  • Evaluate the elasticity of your BMW’s serpentine belt as soon as you hear strange noise emanating from the AC unit.
  • If the belt is worn beyond repair, consider replacing it.

Reason #2- Compressor bearing; It’s damaged

This is yet another possible explanation as to why your BMW’s AC unit may start making strange noises. The compressor harnesses the engine’s power to play its part in the system- which is to compress the refrigerant before pumping it to the condenser. Should something bad happen to the bearing, a distinct rattling or grinding sound will emerge.

Here’s what should be done if the compressor bearing is at fault;

  • Have your BMW’s compressor bearing checked by a certified professional.
  • If it is damaged, get it replaced immediately.

Reason #3- Refrigerant; You’ve added too much of it

Yup, you read that right!!! If you put too much of refrigerant into your BMW’s air conditioning unit, it can cause the AC unit to act up and start giving off a strange noise- a buzzing noise in particular. Besides overcharging can damage the compressor and may significantly diminish your vehicle’s AC unit’s efficiency. So you better be careful while recharging your BMW’s AC.

Here’s what should be done if you’ve mistakenly added too much of refrigerant;

  • Find a way to drain the excess refrigerant which was mistakenly added to the system.
  • Be careful while doing so.

Reason #4- Compressor; It’s clogged or damaged

The air conditioning unit your BMW is equipped with works by manipulating the refrigerant between its different physical states (liquid and gas). The compressor plays an important role in the process. It compresses the refrigerant and pushes it to the condenser so that its physical state can be altered and its heat carrying capacity can be activated. If it acts up- not only the AC unit’s efficiency will degrade, but the unit will also give off a scary noise.

Here’s what should be done if the compressor is acting up;

  • Refrigerant leak, defective condenser, and lack of lubrication are some of the primary reasons why a vehicle’s AC compressor may give up.
  • Only an experienced professional will be able to correctly diagnose and address the issue.

Reason #5- Blower motor; It’s worn

Blower motor plays a crucial role in regulating cabin temperature in a vehicle. It is basically an electrical device that operates at different speeds to provide the passenger with cold air. If it malfunctions because of a bad wire or a damaged electrical part such as a blown fuse/ relay, the efficiency of the air conditioning unit will diminish drastically.

Here’s what should be done if the blower motor has given up;

  • Try to figure out what went wrong with your BMW’s blower motor.
  • If it has sustained some form of damage, repair it.

World Class Auto Repairs: Your Go-To BMW Service Center In Boca Raton

If your BMW’s air conditioning unit is giving off BMW Blower Motor Check a strange noise, don’t fool yourself into believing that the issue will get fixed on its own. Visit our facility in Boca Raton, FL, to get the issue diagnosed and addressed by our mechanics. Technicians employed in our service center are well trained and have years of experience in dealing with complex issues in European cars including BMW. We are also good at handling complicated mechanical issues in Asian imports and domestic brands. Call us and book an appointment today!


We’re here to help drivers all throughout the Boca Raton area take better care of their vehicles. Please call or visit our shop today to learn more or to schedule your next appointment.

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9787 Glades Rd
oca Raton, FL 33434

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