Have had my 14 plate V40 for 3 and a half year now and started getting the coolant warning light coming on a few times in the last week or so. Checked various times and always ok. Happened again on Monday but this time had loads of pressure at header tank. Booked it into my local Volvo dealer who thought it was a faulty thermostat but now think it's the head gasket or a cracked cylinder? I think he said cylinder. Only done 40000 miles. Anybody else had bother? D2 SE LUX NAV.