Olli Snellman

The car is 1992 968 convertible with 100Kkm's. Otherwise in excellent condition but owner have had currently Tiptronic problems.
When cruising slowly in city speeds no problem but when you step on it, car hesitates to take more than 3K rpm's. Then it start to "brake" and you are not able to add any revs. When you release gas, it will act normally.
Also same kind of problem when you try to select gears manually; when revs rise car will stumble. If you try to acclerate several times, the "Tiptronic" light will ligtht up and it shows only "D" in dashboard, not a gear in which the car was. I suppose car is then in the safety mode and it has locked gear 4 as it does when it goes to safety mode. If you have played several times with it, you can reset it and have all the gears back by restarting the car.
If you are not lucky only 2 & R are there.

So far i have checked oil level which was way too low. I added oil according to WSM and it made some progress to better. I wonder does the low voltage effect to Tiptronic's functions. Currently charging is too low, about 12V. I am going to install a new voltage regulator early tomorrow morning , just now too hot even here in Finland, about 32 Celsius

What is interesting, we read with Porsche PIWIS tester all error codes, which Tiptronic has caused. Found several, but PIWIS did not gave any explenation for them, just informed "Unknown Error". Tester also refused to erase these codes.

All advice would be great !

pnbell

Swap a proper 6speed manual transmission in there, that will fix the problem! There is one for sale a few post below yours... ;P

Olli Snellman

Not my car and changing to a manual is too labourous

Jay W

I found that my tiptronic was so low on fluid that I filled it, ran the car around, and had to fill it again. I suppose there was a bubble in one of the lines. Did you re-check the fluid after you filled it and ran it? Also it seems like low voltage would play havoc with the tiptronic system too.