ProjectBoxster7 | projectboxster

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 -

Ready to start! First step is to remove all the plastic shrouds covering the mechanical bits between the frunk and the windshield. Actually, standing in the frunk made it easier to do much of this work!

The attachment points on the bottom of this plastic bit were broken. We'll deal with that later.

The heater core is hidden under the plastic cover in the center of the photo. The wiper mechanism and support struts need to be removed to access it.

The wiper mechanism removed and the struts out of the way. The bracket that those parts were connected to (in the center just below the windshield) also needed to be removed. It may not have been necessary to remove the battery but doing so allows better access.

Now the bracket is gone too. Note the towel put down to collect any stray antifreeze. I also took the opportunity to clean and wax the areas that were hidden under the shrouds. Nobody but me will ever see this but I just had to do it anyway...

If you loosen the coolant filler cap before disconnecting the heater hoses you only lose a few drops of coolant. The hoses are plugged with wine corks.

I used a heat gun to warm the adhesive and the cover came off without a fight.

Keep the heater core level and/or the openings plugged and it can be removed without making a mess. If the core is turned upside down after removing it while, for example, examining it's fins coolant will spill all over, but of course that would never happen...

Look, there's a piece of old foam at the bottom of the heater core opening. The vacuum sucked out the loose bits in short order.

Slicing the cover off the top pivot point of the outer blend door with a hacksaw blade.

You need to remove the top pivot through the opening you just made. Bit of trick but it can be done.

When I get in the car to remove the lower pivot I find even more of the old foam on the floor. It really must be time to do this project!

There's the screw that needs to be removed. With the screw off the pivot can be disconnected from the actuation arm.

With the arm out of the way the screw can be reinserted part way to give you something to grab onto, thus making it easier to pull out the pivot. It took more force than I expected.

The outer blend door removed from the car. The foam on this door was mostly intact but would disintegrate at the slightest touch.

It is possible to access the inner door from the heater core opening but (trust me on this) it ain't easy. Using a borescope to see if there is any more old foam stuck in there that still needs to be removed.

The inner door can be accessed by reaching into the heater core housing and then bending your hand back and around a corner. It is possible, but it is (literally) a pain.

I used craft store self-adhesive EVA foam sheets to cover the doors. Seemed like a more elegant solution than using a bunch of narrow strips of tape.

Jumper cables connected to the battery (on the floor out of the way) allowed me to adjust the car's HVAC controls so I could move the inner door and access both of it's sides. The foam sheet for one side shown ready to be installed.

The outer door ready to be reinstalled. "Installation is the reverse of removal" of course and everything went neatly back together.

This is one of the attachment points that broke off the trim piece in front of the windshield. It appears that the part was just poorly designed. No wonder that it broke. Yes, the other side was broken in exactly the same way.

I first glued the broken pieces back into place.

It seems unlikely that the glue, by itself, would hold for long so I reinforded the joints with Gorilla tape.

Here's the other side. Hopefully it will hold but if you get right down to it it probably doesn't really matter as the only way to tell if it's broken is to take the car apart!

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.

FreeCAD screenshot

Printing a prototype

Close, but not quite right

3D printed prototypes

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.

Broken original and Chinese replacement

Replacement mirrorflap installed

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...

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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!

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!