renault megane radiator filled up to normal level,( rad has been bled for AIR ) I then run the engine up to normal temp, the engine coolant gos down (not expands up ) but does not empty expansion bottle. I then let it cool down for safety to add more coolant, but on releasing the cap no pressure can be heard but the fluid level rises back up the bottle
any thoughts why

chris, September 2011

no oil contamination in coolant water, or any mayo on oil filler cap

chris, September 2011

sounds like the cylinder head gasket has blown.if water is going down then up its being pumped around the cylinder head.its a classic symptom.can you see oil in the coolant water?

stew, September 2011