Air flow weak when heat is on?

[Kyang2018]

Hi guys,

I have a weird issue with my 2018 M3. When I have the heat on, the air flow coming out of the vent is weak. I've tried adjusting the fan speed, turning the dial all the way to heat, turn up climate control to max heat, change it to manual mode, turning the car off/on, etc. I can hear the blowing sound getting louder, but the air coming out the vents isn't getting stronger. It works fine in cool and A/C mode, just heat mode the air flow doesn't get stronger.

I've just changed cabin air filter like 2 weeks ago, I used a oem part instead of genuine. The arrow is facing the correct way, but the two sides of the filter doesn't match up to the old one. Could it be the cabin air filter or something else?

Thanks

[ironviet]

If you hear your vent blowing hard but has little airflow it's most likely something is restricting your vent. Unless you have a full blockage it most likely is your filter medium. I ran into this issue a few months ago. I just went to another aftermarket and it worked better

[Kyang2018]

Originally Posted by ironviet

If you hear your vent blowing hard but has little airflow it's most likely something is restricting your vent. Unless you have a full blockage it most likely is your filter medium. I ran into this issue a few months ago. I just went to another aftermarket and it worked better

I thought it might be the filter too, but the air flow is fine if I switch it to cool or turn on a/c.