Tiptronic gearbox slipping in 3rd

[Gengus]

Hi - I have a 2004 986 which is running well except for one problem with the tip box - and any help really appreciated.

If you coast towards a fast roundabout (for example) with the foot off the gas, the gearbox will stay in 3rd gear as the speed stays around 12mph, but sometimes feels like it drops out of gear, then when you accelerate into the roundabout the revs increase with no drive. The drive will then make a thumping noise / feel 'thump' and pick up drive.

I've had a tip service (oil and filter change), but after 400 miles the prob still remains. Apparently no error codes coming up on the computr either. Anyone know what might be causing this, or what the options are??

Thanks a lot,

Ian

[Gengus]

Perhaps this an electronic CPU problem, or something mechanical with the valves ?? Any help appreciated - not sure what to try next ?

[valter]

How it behaves under hard acceleration from stop? If it is slipping, you will definitely feel how at some gear you will get "disconnected" from wheels feel, when RPM's climbs without any significant acceleration.

[Gengus]

How it behaves under hard acceleration from stop? If it is slipping, you will definitely feel how at some gear you will get "disconnected" from wheels feel, when RPM's climbs without any significant acceleration.

Absolutely fine under hard moderate or light acceleration when driving normally. It only happens when you coast without acceleration down to say 12-15mph, then accelerate quickly with the tiptronic in 3rd gear. The engine then revs without acceleration until it thumps back into drive. I was suspecting the electronics, beacuase it feels like it should drip into 2nd sooner, but instead seem to 'fall' out of gear, then be not sure how to deal with the acceleration.

Thanks for looking,

Ian