overheating

[bigyagi]

went out the other night for a quiet drive, and was staggered to see the temp gauge off the end of the scale. no warning or anything beforehand.
after it cooled down, i re-filled, and bled the system, as per. heat vent to full open etc .
when the gauge got to the mid point (normal) position, no hot air from the vent, only cool. top hose insanely hot, lower hose onlymildly warm, and rad felt cold. i'm thinking the thermostat has failed in the closed position ? any other thoughts etc ?
i'm taking the thermostat out, and trying again, and hopfully, the gauge stays at the lower end of the scale.
bob.

[rmcdonnell]

Makes sense.
Or the water pump isn't.

Hope it's the stat.

Russell