i think something is up with the AC, but with the AC off, fan on, the cabin smells like something is rotting inside. anyone experienced this before? what to do?

thanks

Search this forum for "afterblow" and make sure yours is working. It seems that some S80s come from the factory with it turned off. Quick dealer Vadis job to turn it on.

You have the infamous "aroma de mildew" that plagues many owners of modern cars. The BMW people complain of this all the time, also. First, try to clean your system using the Frigi-Fresh or the Wurth spray, as the other letter recommended. Definitely and clean out leaves and pine needles and change the cabin air filter.

As for prevention, it's tough. The only thing I know you can do is be sure to turn OFF your AC a few miles before you reach your destination. Then run outside air through the system to dry off the coils. If you leave the AC on until you stop, bacteria and other repulsive organic matter grows on the wet coils. Change the air filter annually. Good luck!

http://brickboard.com/ARCHIVES/1998AUG/20008804.shtml

I've used something called "Frigi-Fresh" which is formulated to decontaminate AC evaporator coils. It costs about $6.49 for a spray can.

But of course blow out the drain with compressed air, replace the pollen filter and clean out all the leaves, pine needles, dead mice, etc. first.

-BTC

Could be your heater core begining to leak.

You could leave the heater on high for a while and hope the smell goes away. Usually does after all of the condensation evaporates from the core area. You could spray AtmosKlear (from True Value) into the air intake, under the wiper blades. That gets rid of the odor, but not the cause.
Usually this condition is caused by one of the drain tubes being clogged and holding water. But I did see a car at the dealer the other day which was soo full of leaves and pine needles that no air could get into the fresh air intake.

Klaus
--
98 V70Rawd(101Kmi), 95 854T(85K mi), 88 245(165K mi)

Change your pollen filter. You don't wanna know what mine looked like after 7 years in the car.