I've got a mk3 TDDI mondeo as my daily runabout and it had the typical symptoms of a thermostat opening too early, took ages for the heaters to get warm, temperature gauge would rise to normal when booting it but when driving steady it would drop off to 1/4 or lower. It has never over heated and the cooling fans cut in and out as normal when left idling.

I changed the thermostat today and it is still not coming up to temperature as it should, it is definately better than it was as it comes up to normal operating temperature without needing to drive it as hard however when coasting or on light throttle it is still dropping off to nearly bugger all and the heaters are getting cold.

Any ideas as to what could be going on? It runs fine and uses no oil or water.

Cheers

 

Faulty thermostat?

 

I believe these have two thermostats, so maybe you replaced the good one and not the faulty one

Martin

 

Above is correct I think. There is a second, less obvious stat on the water pump body which i think leads to the oil cooler. Mine had the exact same issue which was resolved by changing the oil cooler stat.

 

Nice one cheers guys

 

Had a smilair issue on my mondea TCDI, was an 07.

As above, there's also a thermostat on the oil cooler. My issue was only resolved when they replaced the second stat.