For the last couple of years the Boxster had been blowing bits of black foam out of the vents whenever we used the heater or AC. Research on the 986 Forum suggested that the problem was due to the foam covering on the HVAC system's "blend doors" breaking down and blowing away. There are several ways to address this issue. Accessing the blend doors through the heater core opening seemed like the least invasive so that's the method I chose. Following the excellent guides posted -here- and -here- on Rennlist I was able to recover both blend doors. Here's how I did it -
My good friend Dave brought his grandson Wesley, I brought my grandson Orion, and we both brought our Boxsters to the Mid-Ohio Sports Car Course for a Grand Day Out watching the vintage car races *and* enjoying Free Rallys french fries!
Like many cars, Boxsters have a have lighted vanity mirrors on the backs of the sun visors. The mirrors have doors that cover the mirrors when closed and display the mirror and turn on the light when opened. We'll call this the mirrorflap and the one on the passenger side visor was broken when I bought my Boxster.
When I examined the broken mirrorflap I saw that the hole in one end that served as a pivot point had broken out. I was able to cobble a repair with a bit of hobby store aluminum tubing and epoxy putty. That worked okay for a few years until the pivot on the other side broke out too. I tried the tube and epoxy repair I'd used before but the "repaired" mirrorflap wouldn't stay open or closed and would rattle obnoxiously. The next step was to examine the unbroken driver's side mirrorflap to see if I could determine what was wrong with my "repair". This revealed a couple of things. The first was that the mirrorflap is a more complicated part than it initially appears. It's not just a simple door to cover the mirror but also has small cams near the pivots that engage springs in the visor's mirror assembly to hold it open or closed and has a tab on the back to press the switch to turn on the vanity light when open. The other thing I learned is the plastic in both mirrorflaps is becoming brittle as one of the pivots on the driver's side mirrorflap broke out too...
About the same time that I was trying to decide what to do about my mirrorflap problems I was also trying to teach myself FreeCAD (to make Ferrari shift pattern inserts) so I thought I'd just whip up a mirrorflap design for my son Andy to make on his 3D printer. I spent lots of time creating a model that was as close to the original mirrorflap as I could make it. Andy printed it and, of course, it didn't fit properly. No problem. I thought I'd just make a couple of adjustments and it would be perfect. Well, the next iteration wasn't perfect nor was the next one or the one after that. He printed seven iterations for me before I gave up. Although I had intended to try again, I decided not to when I found that inexpensive Chinese mirrorflaps with metal pivots were available. When you get right down to it, it's probably just as well that my attempt didn't work out because my design would have duplicated the same weak pivot as the original part. Not only that but Andy's 3D filament printer has a fairly low resolution, printing parts that aren't very smooth, and uses PLA plastic filament as opposed to the more durable ABS of the Chinese parts. Andy also has a resin printer that's capable of making higher resolution, durable prints but it's too small to make a mirrorflap sized part.
The Chinese mirrorflaps have arrived and I was able to pop them into place with minimal fuss so now the mirrors on both sun visors have working covers, just like God and Porsche intended. Gotta say, after all the time and effort spent on this project it's a bit of an anticlimax that it turned out to be such an easy fix.
It would be fair to ask why I didn't order the Chinese replacement or OEM Porsche mirrorflaps to begin with. Porsche only sells the mirrorflap as a part of the assembly that also includes the mirror and housing, with or without a light. Originally, I thought it would be wasteful to buy the whole assembly when I only needed the flap and that designing and printing the flap myself would be a fun project. When I came to the conclusion that making a 3D model of a mirrorflap was more frustrating and less fun I was more familiar with the part and realized that installing a new mirror assembly in the sun visor may well damage the visor and that the mirrorflap could well break if I attempted to transfer the flap from a new assembly to the old. I didn't install the Chinese replacements before attempting to duplicate the part simply because I didn't know they existed.
Replacing the mirrorflaps turned out to be a much longer and more involved project than expected but that's OK. My Boxster now has proper covers on the vanity mirrors, and I have had the opportunity to gain a little experience creating 3-D models so it's all good...