Hi All,

I have a 130ps mk3, and has done 145,000 miles now.

I drove my car the other day for over 100 miles and the temperature gauge did not seen to move very high at all. Sometimes it goes up further (not quite half way) and drops down to nearly cold. I have noticed it does go slightly higher in stop / start traffic, but soon goes down again. I have been having this problem for some time and I am worried the car is not reaching correct efficiency levels. The reservoir after a good run was only slightly warm, and the top hose going into the radiator was the same. I did have a problem a while ago when the hose going into the radiator came off / unclipped, as I drove into a parking garage. No idea why this happened, but I clipped it back on, topped up the coolant / water and all was good after that. Maybe this could have been the start of my problems?

Any idea's ?

it sounds like a thermostat is stuck and will have to be replaced,as for which one is playing up is hard to say as there are two on the mondeo mk3.

I left the engine running for a while at home yesterday to see if the temperature gauge reached half way, and it did. I then took the reservoir cap off. There was quite a lot of pressure released and the water was warm in the bottle. I then put the cap back after a while to see if maybe there was an air blockage in the system. I will take the car out for a run today and see if that has cured it, you never know ?

I had an overcooling problem recently and after looking at this and other forum's threads on this problem I found it to be the thermostat.

I first had the main one changed but it was an after market one. Apparrently these have a too thin a rubber gasket so I changed it for a genuine Ford together with the oil cooler stat. Worked fone after that but as to which stat was faulty I do not know.

Hi,

I have changed the coolant thermostat and thanks to this forum I got the thicker seal from Ford (£4.50).

I had it fitted, bled etc and it is better, but not like it should be ?

I took the car out this morning and it took an age for the gauge to move off stone cold. I then went for a spin (10 miles, mostly fast dual carriageway) and put it under load, and the temperature finally got up to where it should be. It soon dropped however after slow driving at low revs.

The garage incidently reckoned it was the sender unit.

So I ran the engine in front of them for 20 minutes at between 1500-2000 rpm, and the temperature reached and stayed at half way, thus proving it was not as they assumed.

My next course of action is to get the oil cooler thermostat changed and I reckon this will do the job.