Cruising on the continent at between 95 and110 MPH, it didn't take long for the temperature gauge to drop to the bottom of the dial. Back off and all was well again. Does the radiator airflow controller cover this or has mine packed up? Fiesta mk8 Titanium 125.

Sounds more like a thermostat problem. 

 But for the fact that the car otherwise runs at the correct temperature at all times.

The shutters aren't fitted on all models, the thermostat should be able to regulate the temperature. The temperature display is also programmed not to move as much as the real coolant temp so drivers don't get worried about it moving. It only responds to big changes in temperature.

If there is a problem with the shutters it should have logged a fault as they do a self check on every start, so might be worth seeing if Forscan finds anything.

Ta! That's useful.

Forscan didn't bring up a single fault code despite having not done a diagnostic for a year. Just have to change the stat then.

You can watch the shutters do the self check when you first start the engine if you want to see they are moving ok.

I shall try that, too. Thank you.

 

Hmm. They don't move and are open at rest. Looks as though I shall have to fid a circuit diagram...

Alex was right about the stat. Thank you. I finally got around to it having good weather and  the need to change the front pads which were down to 4.5mm. Alfie Treves makes good brakes. These are 49,000 miles old and well used as the car is often going quite quickly and frequently heavily laden. The stat was a little bit of a trial. The cost of diluted coolant from the Ford dealership here made it cheaper to take a day trip to England and buy some there. Once I had bought oil (and three jars of Marmite which is getting on for twelve pounds a pot here,) I was quids in. Having done the brakes in half an hour, I decided to tackle the stat. Air cleaner pipe off, Grips to remove the clip, pull the pipe off and drain. Remove header tank cap..... @##!!'~! the top of the cap came off, leaving its guts firmly stuck in the filler neck. Getting anything out here takes weeks and the local dealer is as useful to me as death so using a drop of plus gas and several repeated incantations of the kind mechanics use to ward off evil spirits it was carefully prised out and reassembled. Once the new thermostat was fitted and a couple of litres of coolant added,  I squeezed the top hose and found the housing leaking like the Cabinet Office. The rubber that goes around the outside is much thinner on the Quinton Hazell replacement so I used the one from the original stat and all was well. I do like cooling systems that don't need to be bled! Temperature went straight up to the right position, the car ran better from cold and once I have bedded in the new pads, all will be well.

The oil life is down to 45% so it is due for a change this week as well so the hard working little Ford will have had about two hours of work in a year's motoring.

It still doesn't handle like my old one though so I have ordered a set of polybushes for the rear beam as it has always seemed to be a bit rear wheel steery. A job for later.