How often should cabin/air filters be replaced? Looking at a 05 911 with 17000 miles and the independent who did the PPI is recommending that along with the oil change and replacing the serpentine belt. Does all of that sound necessary or is some of that mechanics just upselling?

 

The oil change is a must if you don't know when it was last done IMO. Because of the age of those other items (assuming that they are the originals), I think the cost is worth the piece of mind of having it done. Time can wear on these items just like miles. You could live without the cabin air filter, but the effectiveness will break down with age as well. This is an easy DIY project if you want to save some money.

Just my $0.02

 

How much of this could be do-it-yourself? Just the cabin filter? How do you check the wear on a serpentine belt?

 

Cracks on the belt?

 

I change the filter once a year @ the end of the May leaf & pollen season. You know how bad the spring leaf & pollen is in Tampa Bay. I remove it & vacuum it November. Cost for a new filter is $26.71 (http://www.germanfilters.com/911-car...3090_3094.html).

Serpentine belt: Good post with pictures @ Rennlist - http://forums.rennlist.com/rennforum...t-failure.html