I own a 2004 mk3 Mondeo 130 TDCI with 47k on the clock and over the past few months I’ve been having problems with the cooling system. When accelerating on the motorway the engine heats up as normal but as soon as I slow down in traffic or come off the motorway onto slower roads the temp gauge goes straight down to about 60 degrees and less sometimes. The thermostat was changed which made no difference and a diagnostic test was carried out by Ford which came up with nothing. As a last resort the thermostat was changed again and it seemed to do the trick, the engine was heating up very quickly from cold and the temp gauge showed 90 degrees at all times. This lasted about 3 weeks but for some reason the car is over cooling again with exactly the same symptoms as before. Can you tell me what you think the problem might be? Thanks in advance for any advice.
sorry but we would need to inversigate this concern