It's been around 100 degrees over the past week or so. When I start my car and the AC kicks in their is a strong musty smell which lasts for about 20 seconds. Once the air in the system cycles through the smell stops. Any ideas what might be causing this? I thought it might need a new filter but if that was the case would suspect the smell would persist for a longer period of time.

Thanks in advance.

im going to guess you have had your AC running prior to this. the cabin filter wont be the root cause of this.

what you are smelling is the dust/bacteria that collects on the coil as its sucking air. it dissipates quickly thanks to the plasmacluster system on board.. ;-)

you can minimize this by shutting off the AC and just running the fresh air/vent to dry the condenser so the bacteria doesn't collect on it as it sits.

there are "bandaid" procedures you can do but you won't totally eliminate it. its just best to turn off the AC but let the vent/outside air run for a couple minutes before you shut off the car. search the internet to find solutions to help combat this a bit.

yea it may be inconvenient but that is what you can do.

now if you decide to spray something into the intake at the cowl, do it on the old cabin filter and not the new one (if you are considering replacing it).

Wow, very detailed info @marctronixx. Thanks for the advice.

it works bro! ;-) but sometimes its not practical to run it like that as i can get hot quickly, but it will sure keep that smell out of there. it's a common issues on many cars, and there are some sprays you can use to help.