Over heating

[nathanl22]

ok so this is my first post
hey
just had a 200tdi convertion on my defender 90, and already there a problem.
the engine is over heating was around 3/4 when i stoped drivign it but am sure it would have gone hotter. Also i noticed that the glow plug was coming on then goign off while driving. Could there just be a air bubble in coolant or something more serois?

[jo'bo]

it could be an airlock

buts its just as likely that there's incompatibility between the sender unit and the dial and everything just fine