Thanks for that tip about the chains jay will pass it on to whoever does the head, if its the head. There's no signs of mixing on the dipstick, the coolant in header is still blue.There was a small amount of dark brown gunge on the filler cap but I put that down to the previous owner mainly using it for short inner city journeys. What colour would the gunge be if its the head gasket? Also can't see any obvious signs of leakage from the engine or hoses apart from under the header tank were it drips out of the overflow, but hasn't been overfilled! Used it for work other day and coolant in the mi