OK, I've tested this out on my car now. Obviously every automatic gearbox allows a little bit of slippage via the torque converter. (There's a good explanation about 'slippage' in the following article http://www.bankspower.com/Tech_under...rqueconver.cfm.

When I slot my car in 'manual 3rd' and plant my foot down the revs rise by around 500 to 750rpm whilst the car accelerates forwards and then the revs build upwards from there. It's not like a manual transmission where the engine revs and transmission accelerate precisely together, but it's nearly as good. It does this in 1st, 2nd, 3rd and 4th gears then only at low revs in 5th gear (around 2500rpm or less) and it never does it in 6th gear. It's nothing like changing down a gear and is 'clearly' the slippage of the torque convertor as the fluid inside is compressed and finally locks the impellor and turbine together.

It really has nothing to do with the valvetrain as the engine does not change at all, it's just the transmission allowinga bit of give before engaging solidly.

What kind of revs does yours rise by to cause you to be concerned?

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