1.3 temp./compression problems

my driver seems to have trouble reaching compression i feel, and when it does it runs very hot! the head gasket hasnt gone as there's no mayo, any ideas ppl? as i write this im sad to say that my car was actually stolen from outside my house, they smashed the windows and drove it till the petrol ran out, and let it roll down a bank in 1st into a tree. not too serious damage, new bumper and front panel needed, and thats it i think.  worst thing is i have to pay ?105 recovery and ?12 per day storage! bl**dy cheek!

oh my what a bunch of gits