I have a 2005 2lt TDCI ....last week i noticed tht my temp gauge was eratic moving from the half way position to below 60 then back again ...the car wasnt over heating and I had heat in the cab no obvious faults....Today I called in the AA he tested the coolant temp by plugging in from the ECU the running temp after letting the car idle for about 15 mins was 85c and the needle sat at the half way mark ..his conclusion was a coolant sensor fault or a gauge or wiring fault....so 2 questions .., is there a accessable multi plug connection for the dash which may be loose andwhere and is the coolant sensor located on the engine ....I personally think it may be T' stat issue , any ideas....

thermostat is the most likely culprit, but I think the block connector at the back of the cluster is worth checking and lubricating with contact cleaner.

Thanks for the reply ...ok 2 questions ...the best way to get to that multi plug ...and also where the hell is the thermostat ...gonna need to sort this myself as cant afford garage rip of prices prices Ps i google it and apparently there are 2 t'stats ...so where do i start please

You need to strip out the cluster remove it and then clean it with contact cleaner.

As for the thermostat, I don't know there exact location, but you would have one near the radiator generally.

check out fordwiki for the guides on the two thermoststs.

Thanks for that ..that is a amazing site plenty of info ...however the t'stat change appears to be petrol engine orientated i cant find anything about 2 stats or even the temperature sensor ......will keep the site for future reference though looks better than a haynes ...

the second stat is know as the oil cooler stat and is located in the pipe to the oil cooler.

Thanks all ,,,,I now have 3 possibilities to the problem ....the temperature sensor ( i have still to find ) the oil cooler stat and the main stat ...where to start lol ....The last stat I changed was on a mk 5 cortina ..lol 30 minutes and 3 bolts if i remember correctly ....

Back in those days, it was relatively easy; look at the engine, on the bit of the engine closest to the top of the radiator, and there was a big tube. the thing that the big tube went in to was the thermostat housing, and just in case you were in any doubt, it was thermostat-housing-shaped. Either two or three bolts held it to the engine, and if you removed those, the housing either fell off, or did with a little 'encouragement'.

All thermostats were very similar; there was one mechanical type, and maybe the temps were slightly different, one car to another, but you could fit the thermostat from nearly anything on the road to almost anything else.

The 'sender' (resistive element for temp sensing) was usually in the bowl below the thermostat. there was a single wire that went there, and that was the wire that was broken if it didn't work electrically.

Now, unfortunately, it has all changed and even finding the thermostat requires a degree in advanced squid sexing, before you even start (well, on a MkIV, anyway)! And it costs about £50, because the thermostat isn't just a thermostat any more, but it is moulded in to a weird collection of rubbery bits, that looks like an unhappy squid after a bad night out.

I'm not sure that helped, but remember that it could be worse....

I took the car to the garage yesterday ..he confirms that symptoms are a thermostat failure poss water pump...the needle on gauge sits at just above the 60c mark and moves up and down slightly with engine load and I am sure i can feel a temp change from my vents as well ...however when i take car upto 70 -80 the needle will move upto its normal position 1/2 way ...the garage has discountered the oil cooler stat ..i have been quoted about £85-90 ....any ideas ....I cant afford too much at the moment ..lol..

I can't quite see a failed water pump making the temperature go low. High, yes, but not low, so I'd look at the other possibilities first.

i would have gone for the oil stat first as this is one to play up the most.

I don't know what to believe I cant afford to mess about ...if he fits one and it doesn't fix the problem it will be back again more time and coolant and more money..Perhaps i should supply both stats and ask him to fit both on the other hand is there anyone near Ipswich who would like a job and fit them for me lol ....

this is what the coolant t-stat looks like,, not cheap items..

this is what the coolant t-stat looks like,, not cheap items..

that thermostat housing is for the later mondeo , not the 2005 tdci, 2005 mondeo is fairly normal thermostat, 3 bolts holding it in housing , thermostat £8 including o ring seal, 10 minute job

that thermostat housing is for the later mondeo , not the 2005 tdci, 2005 mondeo is fairly normal thermostat, 3 bolts holding it in housing , thermostat £8 including o ring seal, 10 minute job

thanks m8 ,, my mistake ..

try here for what they look like..

http://www.ebay.co.uk/sch/i.html?_from=R40&ghostText=&_sacat=0&_nkw=Thermostat+mondeo+2005&rt=nc&LH_PrefLoc=1

I am getting confused now , How could something that used to be so simple get so complicated .. I have looked for a replacement , and it shows what i recognise as a t'stat ..when i look on fordwiki i see something different (a stat in a housing) ...ford have quoted me £90 for both stats ..n line sites between £20 30 ..can anyone point me in the right direction here ....I can use tools and do repairs ect if i know where i got to get to ....I knew i should have bought BIKE ....

thanks all

As ive said before, its 3 bolts holding thermostat housing on, remove these, remove thermostatm fit new rhermostat, housing back on refit 3 bolts, job done . As the saying goes, its not rocket science, lol

LOL I have looked on ford wiki ..it talks about removing headlights etc ..the picture does not look like miy stat as i have ordered .....where do i find the stat housing , i am not as agile as i used to be ....

R3moving headlight is on the petrol mondeo.

thermotat housing is imbetween battery, airfiler, and powersteering pulley , if you look you will see 2 small hoses on the top

looked at one this morning, either 7mm or 8mm bolts x3 on housing