Technical Engine seemed to overheat; 105JTD 1999

[BeaglePup150]

The temp gauge suddenly moved from normal to the top of scale. On tickover the fan started, none of this has happened before.
I checked coolant a little low, found two bleed valves on a pipe near the rh side fo the rad, when I opened them a fine vapour; a mix of air and coolant came out under pressure.
It seems to be ok now but what could have caused it?
also what is the correct coolant? I am considering draining and replacing the system,
and are there any other bleed valves on the cooling system?
If there is a small leak, should I use radweld for something similar or should I just use it anyway?
Thanks
Terry

 

[viper1253]

your thermostat may of stuck closed, meaning the water around the engine could be cooled. thats cheap and easy to replace.

 

[BeaglePup150]

your thermostat may of stuck closed, meaning the water around the engine could be cooled. thats cheap and easy to replace.

Thanks Viper.
do you know how many bleed valves there are. and what type of coolant is used
Terry

 

[fbarcode]

Hi,

Just how 'sudden' the temperature gauge jumped to red? My gauge keeps jumping from time to time, but it is caused by faulty connection and quick slap on the top of the dashboard (above the temp gauge) 'cures' it instantly. However, this might not be the problem in your case.

 

[viper1253]

there will probbll be 3. 1 on the rad 1 on top pipe and 1 on bottom pipe.

 

[BeaglePup150]

Ah a 3rd one thanks Viper I will look for it, I still get a little air from the lower two.
regards
Terry