I run a 2.0 8v in my MK2 and it has a slight power surge around 3000 rpm. Below that it feels like it's not quite running on all 4 cylinders - it still runs good but after 3000 it's really smooth and you notice the extra few hp. It can't be a hot cam because it would have to be pretty wild for the power to come in at 3000 rpm and there isn't a big rush of power.

For the past week I've had a water leak from the radiator overflow bottle. Every day I've added about a litre of water so last night I took the bottle off looking for the leak. The water was coming out of the top (square) hole which is exactly where it's supposed to come out when the pressure gets too much. There's no valve so I checked out the screw cap and found the O ring was half pushed out of it's groove.

Now that the O ring is sealing properly there's hardly any power surge around 3000 rpm. Power below 3000 is now smooth.

Try and figure that one out!

Cheers

Paul