Austarion

Came across this on some other site and was suprised how much air was in my cooling system.
Cut bottom off a drink bottle and tape the screw top end into the top of the radiator,block off the overflow ,open the heater & run the motor
and when the TS is open the coolant will expand into the bottle then squeese the lower return hose and when the trapped air bubbles rise you will see the water level in the bottle drop.Let it cool down and do this procedure 3/4 times.

I must try this on the MX5 i think it mite have air in the system!

There's an article in the latest Zoom mag about this...same method..they say do it a couple of times to get it bled fully.