Airlock

[garymumford]

How do I get rid of an airlock in a ford fiesta or do I have to take it to the garage?

[tigga]

They normally find their own way out after a good run. What makes you belive you have an airlock anyway ?

[Toureman]

I presume you are talking about your cooling system.

There are usually 1 or more bleed valves in the highest points of your cooling system, these must be bled until no air bubbles come out as you do with a house radiators, bleed them with the coolant topped up and the engine running.

If you do not know where they are you will have to get a garage to do it.

[Big Bri]

its usually the heating system control valve located under the wipers on the bulk head . needs replacing if it is not blowing hot air

[tigga]

If it is the problem Big Bri has pointed out, the replacement HCV must have the correct serial number otherwise it will overheat, they start with either 98fu or 96fw.
Make certain to check this.