And the pipes keep building up pressure and now there is a tapping noise in the top of engine. we bled the water system and then drove it and the water started circulating properly for a few hours and then we checked the pipes again and they were hard again and there was air in the system and then a tapping noise like hydraulic tappets clicking,the noise was coming and going can you help
Sep 24, 2011 at 9:43 PM