Good morning fellow Audi enthusaists!

I been dealing with an issue for quite a long time and I would like to throw it out there and see if the community has an insight.

I have a 99 audi a4 1.8T with the tiptronic. Every once in a while, usually while in low gear 2-3 shift (and 1-2 on occasion and 3-4 super rarely), and almost always while inclined (garage ramps, steep hills), the shift will be delayed and the engine will neutral out and rev up and then the shift happens and it slams. If I "go slow" and try not to upshift or hold it using tiptronic, it works just fine. It never has any problem staying in a "gear" it is already in.

As a side note....in 5th at 80 mph....if I play with the throttle, I can make the rpms move almost 300 rpms higher if I lift off the gas and reapply. Slipping band or is this an electronic lockup not locking up?

Anyway...

I've asked my mechanic to check the fluid levels and he reports they are at proper level (these guys do audis so they know how to check it). I've also had a leaking trans cooler and had the fittings replaced. I dont know....to me, this sounds like low fluid or insufficent flow or fluid flowing away from the AT fluid pickup tube but I am wondering if the community knows of a problematic solenoid or other user serviceable part that might be the culprit.

Thanks in advance and happy motoring!

Pete