Join Date: May 2005
Location: Auckland New Zealand
Ive been having similar problems with my 156 GTA selespeed.
I can't offer much of a solution yet, as when I feel I have the problem fixed, it reappears.
Started with being stuck in second gear. tow truck to dealer - fix was the 'proper' selespeed oil put in.
Two weeks later, stuck in second on the motorway again. Another tow truck, this time a brake switch fault, the selespeed wont change gear as it thinks the brakes are on.
Three weeks later, stuck in second again on motorway. Hissy fit thrown at dealer, who only seem to rely on (unreliable ?) fault codes. After prompting from me to check the running temperature, they found that only one fan was working and that it needed a new radiator.
Three months later ( a few days ago) stuck in sixth on the motorway. twice. Maybe I should avoid motorways. Restarted fine, but a hassle to do this while cars are piled up behind me. I am waiting for a new radiator expansion tank and it could be linked to the lack of pressure in the system.
So your problem could well be linked to your higher operating temp, although 4th seems a strange gear to be stuck in, normally the limp home mode is 2nd gear? Might also pay to check out the GTA section of this forum. A few people have commented on heat effecting their gear changing and possible linked to needing to clean the selespeed wiring connectors.
The good news is that none of these problems seem to indicate an expensive gearbox problem!
Personally I have found the fault codes to be unreliable if there is a temperature problem.