car running awful

[novalew]

ok people heres the story

I blew through a head gasket and replaced it skimmed the head and changed the stat.

It started losing power again so i thought it was the same thing so did the above again. Its been two days now and car has lost power again and last night i opened my header tank while the car was running and the water was bubbling up!! !!!

was goin down A5 in 5th and it wouldn't go above 4k ??

Any ideas ?

Ive given it 2 services in 4 months (plugs, filters, oil) do i need a new dizzy/rotor arm?

Its a gsi nova sorry.

Any help would be appreciated.

[Adam]

Of course it bubbles up, its a pressurised system. Once you remove the cap the pressure is lost so the coolant boils.
Does it go above 4k in other gears?