over heating v6 4mo

[4mobora 0]

if you drive for a while it stays at 90deg then starts to creeps up to be 130 flashes, stop check coolant, and the fans spin on full constantly. the coolant is full, the real head scratcher is if i turn it off with no ignition on for around 3 minutes and turn on the engine the needle goes to and stays at 90 deg until it does it again 5 to 10 mins later. the 3 min off time would not be sufficient to cool down 40 degs. any help please also i noticed the header tank fills right up to the top but drains down slowly after the switch off could it b a faulty stat or temp sensor

[cabrioman 6]

u sure the system aint pressurising... do the hoses get hard ???

[4mobora 0]

yea its defiantly pressurizing the hoses r hard for a while but it goes after a few minuets also the air that comes past the radiator from the fans is cool suggesting no hot hater is flowing through the rad otherwise hot air would be present sometimes the problem starts ie the temp gauge goes up but sometimes ive seen it drop back to 90 deg im thinking stat not opening or water pump not flowing the coolant mm im not sure its very annoying

[cabrioman 6]

check the small hose goin to the expasion bottle when its runni if water is comin out of it the water pump should be ok if not ur pumps gone .... only way to test the stat is to remove it so if ur removin it u mite se well replace it mate hope this helps .... as the hoses are gettin very hard u mite hav a head gasket problem ... try and get a sniff test done

[4mobora 0]

cheeres the little hose leading to the header tank does run and seems to circulate the water