I know this is an old thread, but I am resurrecting it for a good reason. I too suffered from the issue many of the older Boxsters are having with no heat. I did all the burping/flushing/checking coolant stuff, and I was convinced that lack of flow to my heater core was not the issue.
Now this was all back in September when it really wasn't cold yet, so like many of us would do I procrastinated. Plus I had another car to drive, so the lack of heat in my Boxster really wasn't a big deal. Anyway, now it is January, and I've sold my other car. The Boxster needs to be back in daily use for the time being, so damn it, heat must be found!
Back in September, I had found a tutorial online that indicated that if you had these two symptoms, then there may be a really creative fix. The two telltale symptoms are:
- Little or no heat, even after the car has reached normal operating temps.
- Tiny little bits of foam blowing out of your vents.
If you have these two then the following link may be the fix for you. I'm posting this here in this thread to document it, since it has disappeared from it's original website, and is only online in PDF format here:
Link to PDF
Basically it involves doing some surgery to the heater box
under the front bonnet. No need to pull the dash etc. At first what is being proposed here may seem too good to be true. let me assure you, it works. After about 3 hours of following the instructions, I now have all the heat I could possibly want.
When you read the instructions, at one point the instructions mention using electrical tape to cover the door with, it will make sense when you read the process. I have an improvement to offer. I used
this stuff, which is available for about $5 at any home improvement store. Worked great, and I think will hold up to the heat better.