Just had a call from local garage.had a quick check over .everything seems ok compression is good.no sighns of water leaks.going to do a sniff test soon to confirm if gasket has gone.hope its good news but dout it.how much reserve would people put on my car if they wer to sell it.i dont really want to but i need to.i can understand how the car drives no diffrent to before just when you give it boost for a period of time.