Oh font of knowledge, I think I'm going mad.
Ford focus, 2L petrol
has been overheating for the last week to ten days
water and oil levels ok
Fan is kicking in no problem
intermittent at first, going up under load, then dropping a bit when downhill - actually seemed to drop as the revs increased too (?) - at that point, hot air blew through the vents ok
but last two journeys constantly climbing over a little over five miles to the point of engine light coming on, and no hot air through the vents if I try them, and the water reservoir was full to the top with hot water
have run the dashboard diagnostic and seen it climbing on both cylinder head temp (got to 124, then light comes on) and coolant temp (was reading 139 degrees!).
booked it into garage, thinking its probably water pump - they have pressure tested system and its ok, but they cannot replicate the overheat - they put it running on tickover this afternoon, and its sitting in the middle of the temp, and the fans are kicking in.
could there be anything I've missed - my understanding is that if theres no heat through the air vents on a hot engine, then its almost definitely the water pump.