Hi all

I've finally got my Escort cosworth back on the road after 5 years (its a long story). I melted no.3 piston and had the engine rebored and rebuilt but only just getting it back on road. I believe the piston melted due to inadvertedly fitting a standard fuel pump to a chipped car.

Anyway, got it through mot today but was hoping a nice run would have it running sweetly. It didn't. It feels like its misfiring (although it idles ok) and boost gauge will hardly rise above zero. The water tank bubbles slightly at idle (but clears if revved a bit) but once engine is up to temperature the bubbling in the header tank goes crazy once the engine is switched off. It's more like its boiling rather than bubbles you get from a blown headgasket. It continues to bubble (or boil) for several minutes after switch off. It will start and tickover fine first turn of the key, hot or cold. The bubbles in the header tank come out of the top connection (the one that returns from the turbo).

If left idling the car will rise to half way on the temp gauge and maintain around this temp as the fans cut in and out.

Any ideas or any questions?

John