Miss fire and overheating

[Paulgb]

So have had current MGF (2002) 1.8 for a couple of years, had an issue last year with water leaking from thermostat housing so car has been of road in garage as didn’t have time to get to work on it. So have now replaced housing and stat, flushed system through and left running for a few hours absolutely fine. Took out for a run today and temp gets up to just below halfway and car starts to misfire and then temp starts to rise, max 3/4 stop car and bottle is now full and let off steam. Let cool down and top up, get car home and plug in reader and get cam shaft position sensor fault. Could this be causing misfire and therefore over fuelling resulting in overheating or does it sound like more than one issue. Oil and water show no signs on HGF

[talkingcars]

I hate to say this but I would suspect the HGF if the header tank is filling up and the temp is rising.

James