Surprised nobody has asked the symptoms...?
True
Problems started a while back, and thinking it all through may simply be a couple of different problems.
In the bad winter a few years ago the car froze solid and when started the water pump impeller must have come off and the car started to over heat, off to the garage and new water pump fitted etc. Left the garage went for a test drive, ok at low speeds but hesitant (misfire) at full throttle into the higher rev range.
Problem settled and was ok for a while then every now the problem returned (more often when the engine got to full running temp). I then ended up buying the 2.2 and ran that for a while till the tax ran out and then SORN it and went back to using the Elite.
January this year I was helping a mate move the contents of her business and during the long bouts of idling I noticed the heater was getting colder and colder (temp gauge was showing normal) when we were done the car was driven home, (normal speeds) and the temp gauge started to rise quite fast, pulled over, turned engine off and sat for a while, restart the car, temp fine so drove carefully for a couple of miles and the temp raises again. did this 3 times and then parked up at home and left the car parked.
So possible ongoing electrical fault (interior light when switched on seemed to dim/brighten with the engine miss.) thoughts that it might be a cable connection from the fitting of the water pump job, (maybe stretching an electrical connection that was'nt pushed back on firmly enough.(or the plug gaps, new plugs have been fitted, read a post about curing an ongoing misfire by mark dtm, but plugs were fitted after the misfire started)
Also the overheating, considered it could have been the heater matrix, maybe crud, or air lock.
Must admit, car started first time with a freshly charged battery and drives ok, but only turned car round so the engine never got chance to warm up, had checked header tank before starting and it was empty (but had been stood 8/9 months