Hi,

I have a 1997 993 S Tiptronic, everything original. I had the Tiptronic completely rebuilt two years ago, at 80K miles (all factory parts). I also had the micro-controller chip replaced. I won't go into the details but it was a long ordeal. The car worked great for two years and about 8 thousand miles, and then the forward running gears stopped with a sudden thud.

The shop ran diagnostics and error codes indicate that the tiptronic controlling computer is bad again. I find that hard to believe, unless of course there is some other electrical problem with the car that would cause the chip to go bad (electrical problem somewhere causing high voltage or high current or short that would impact life of the chip). These chips should last a very long time, the first one lasted over 10 years (it should have lasted 100).

If anybody has experience with this type of problem I would appreciate any insight you have. These chips are now about $2500.00 (up from $1,600.00 a couple years ago); I understand there are only about 40 left at the porsche factory.

thanks,
Andrew

P.S. I love the car and am the second owner, got it with 40,000 miles on it. I have owned it for seven years and plan to keep it forever. Its the best driving machine I have ever been in. However, in my experience the reliability of the car is very different from what I have read online and in the literature. I maintain this car mechanically very well. However, this car breaks down all the time. The list of mechanical issues that have arisen is incredibly long and started at about 50,000 miles. The most significant was the complete engine rebuild, then the transmission, wheel cracked, tach, on and on and on it goes. I drive it hard and fast at the track, just like it was born to be driven. Still, nowhere close to the reliability/robustness I was expecting. The driving experience though is beyond what I could have imagined.

 

I can relate to this as I owned an '87 911 for 9 years and had many issues with it. So when I read the old cliche about 911's being "bullet proof" I want to tell them BS!

 

Painful as it is, I suspect you know the answer. Though possible, it is unlikely that you are going through a 'phase' in which most of the parts that will fail are failing now, and once replaced, your car will be back to it's dependable self. But more likely, some combination of a 'troubled car' (not a technical term, but it is a technicians term) and somewhat higher stresses from the track are causing multiple and repeat failures.
For me, not knowing if and when this 'phase' may end, coupled with the gnawing sense that you will be left stranded, or with a big bill, or both would be enough to choose to move on. Sell the car for what you can get, and buy a low mileage equivalent model.
And I assume you'd want an equivalent model because you've tried Porsche's older and newer and found this one to be just right. If not, I'd suggest you try a modern car. They are more reliable, have a greater performance envelope, and still have the look of a classic Porsche. More or less
Good luck,
V