C70 engine problem

Hi there,

I have a '99 C70 T5 Auto Convertible and today it's developed a fault when accelerating hard.

I have no idea what might be causing it and I was wondering, if I described the problem to the group, if someone might be able to point me in the right direction so I can do some research (I like to be informed before I get ripped off at the dealership ;)

With my auto, there's a little kick-down facility where if I floor it, there's a mechanism where I can push the accelerator slightly further to the floor to cause the auto to change down a gear (or two).

This morning, with a semi warm engine, I press the accelerator to the kick down point, it kicks down, accelerates hard until it reached about

4 1/2 krpm and then "topped out" - it appeared to lose power, and then engine was revving but the car no longer accelerating, and not changing up either.

It also sounded like something in the engine was not engaging but merely spinning madly (not the turbo, but something else - I recognise the turbo whine ya know ;)

I don't know if it's related, but on Thursday I had to have the battery replaced. The old one had gone completely flat - to the point of no lights on the dash board - not even dim.