Right i know this is a funny one but i have transplanted a mondi TDI engine into my Mk3 Fez diesel N/A.

Anyway the conversion was a success and it runs well, but now after a few weeks of running its decided to go tits up. It seems to be over heating the coolent system and pressurising it some how.

The engine has had a full re build and the head has been pressure tested so no probs there new head gasket n all. It seems like all the steem is converging in the top pipe which goes from the rad to the thermostat housing . Could it be that the thermostat has gone tits up and not opening???????

Also the turbo seems to be going on and off boost by its self. Like it will have boost one sec the it wont.???? Week actuator ?????

Thanx

Andy