Hi All

Would those of you with ST's mind letting me have some info?

My temperature gauge isn't getting to the middle of the dial and I suspect that my thermostat is stuck open (same problem I had in the BMW!).

If you use the cluster test mode (hold the trip reset button while turning on the engine and releasing when it says 'TEST') cycle through the options until you find Engine Temperature. Would as many people as possible do this so that I can determine what is the 'correct' running temperature for this engine? For the record, mine's sitting at 73C, which I think is low.

Thanks a lot!
Nick

Sounds like you've got the same problem as me, nick. Now that the air temp is low its showing up, the thermostat sounds like its stuck open and its not able to get fully warmed up before opening, so its just circlating water regardless.

Part was £36 for thermostat and housing, did it myself on my drive ( i'm sure you're more than capable of doing that! )

See my thread http://fordfiestast.co.uk/ubbthreads.php/topics/524367/Not_holding_temp,_just_confirm#Post524367

I didn't have to change the pump but forgot to update the thread when i changed it
I've seen these symptoms crop up on a couple of forums now, sounds like it might start becoming a common issue.....

yeah my old (56) st did it, was running as low as the 60's, current st (08) is starting to do it, will drop to 70's at 70mph and only upto the 80's around town, it's only when sitting idling with the heater off that it will get into the 90's, i'm driving around with the heater off most of the time at the moment until i can get it sorted out.

mpg will take a bit of a dive too as well as the heater not being as warm

thermostat stuck open? The kit I work on they usually stay shut when faulty! not bad when the opening temp is only 73degrees!
Standard duratec engine is 89degrees I think? Is it easy to get out, I can't remember? Could always pull it out and drop it in warm water to test it works.
Again is there bleed valves/points on the cooling system, one before the stat and one after? You'll be able to tell if it's open or not. Same with inlet hose to the stat hotter than the outlet

Jack - I definitely think that the thermostat is stuck open. I had the same problem in the BMW not two weeks ago and in fact the shaft of the stat had sheared, lucky I caught it when I did. Once I'd replaced the thermostat it warms up quicker and gets to the 90C it's supposed to.

I did the water pump a couple of years ago after a monumental water leak issue (two leaks appeared simultaneously!) and I'm not losing any coolant at the moment.

EuroCarParts are showing a stat for the 2.0 Duratec for £5, no housing though. The ECP one shows the opening temperature as 82C which seems about right, maybe a little low. Did you get the parts from Ford themselves?

MPG is dog sh*t at the moment, showing 26MPG on the display and thats a mix of urban and extra urban.

Another job for a weekend I think!

Hi Nick, just tested mine, dial at the middle reading 85C

Like all of said, sounds like your thermo stuck open, get those tools out

Thanks a lot Kev, reaffirms my suspicions!



That was after an hours drive and 10 minutes parked up idling, (when I stopped and turned off the engine the radiated heat can heat it up a bit which is what happened here). When driving (and getting airflow) it was hovering around 72-73. I'll pop into Ford on Monday to pick up a new thermostat and housing.

EDIT: This photo makes it look like the problem isn't as bad as I'm making out. Probably should have taken the photo before I'd switched the engine off to show the needle in its current position lol

Mine was 79 with the dial in the centre... after standing for a few minutes (how long it took me to work out how to display it)
I'll check it again next time it's warm to see if it's any higher.
I also did the thermostat a few months ago as it was running cold.

yeah i'm around 75c at 70mph, boot it and you can see the needle drop, best getting it from ford as it looks like they tend to fail in the open position, far better than it staying closed and cooking the engine, i really should go and get one myself next week, from what i remember the housing and stat was one piece anyway

Nick i just ended up buying a genuine one from ford and it was a reasonable price.

Yeah, £35 from

OK, must have waited too long last time, today immediately after driving it was 88

Picked up the thermostat + housing today, £35 from Ford. Looking at the technical manual it shouldn't be too difficult - just hose clips which are the biggest problem (but I'll probably replace them with jubilee clips instead).

I'll do a replacement guide at the weekend for the benefit of anyone else who may be having to do this job soon!

I was going to do one but didn't get any photos, i highly recommend having a 1/4" drive set, i had a 1/4" ratchet on a 6" ext and i think it was an 8mm universal socket, literally saved so much grief for access.
I took the headlight out and worked from there, the clips are a pain as always and replaced two with jubiliee clips.
It would have been a world easier as well if i had taken the aux belt off but didn't want to add another job to the list at the time.

Untitled by Jack_Pearson, on Flickr

This was the photo of the "access" i had at the time.
As i say you're handy with the spanners, i managed it so!

I've done the water pump on mine so know how tight it is for access behind there. The only thing I'm not looking forward to is the hose clips, the rest shouldn't be too bad at all really.

I had a pair of pipe grips to get in and have them, you can get ratchet pliers which are pretty good for them!

best thing for the hose clips are waterpump pliers, makes it so much easier to get them off.

I'm sure you know this but make sure you bleed out the coolant system once you've put the new thermostat in

All in hand buddy, cheers. Had to bleed it after replacing a coolant hose, and then again after doing the water pump.