Hi guys,

For a a couple of months now I have been noticing my temperature needle floating around between the mid way mark (Where it should be) and the mark below, sometimes even touching the mark below.

As a consequence, the fuel economy seems to be suffering. It could be the colder weather but the drop of 5-10 mpg seems a little extreme for that.

My question is, is how likely is this issue related to the thermostat or whether it's related to a sensor issue? Are there any ways that I can easily tell which issue it might be?

Thanks in advance

 

Thermostat, comes with the housing and sensor built in, make sure it's genuine Ford though as aftermarket ones are a bit poo

 

Thanks for the reply Yeh I've noticed that it seems to be an all in one unit, where exactly is it located? I changed the coolant during the summer which is a pain in the arse if I lose it all trying to change the thermostat! Will have to try and replace it without losing too much coolant

 

It's at the left end of the manifold (looking from the front), nestled just under and to the right of the power steering fluid reservoir. Access is tricky, a bit easier if you take off the offside headlight.

 

yup, 3 bolts and 2 hoses plus the electrical connection

tight for space so get an extra pair of hands to help you

 

Oh yay, I love it when manufacturers make things easy to access! Thanks guys, I'll have to give this a shot soon!

 

Hey bud, is this definitely doable without taking the front of the car off? I'm looking at tit as we speak with the headlight off and the top right bolt seems like its directly behind the intake and would be impossible to get to? Be great if you could let me know

 

yeah, it is.... sorry forgot to mention I had to use an extender and a universal joint on the socket to be able to get it in to the bolts

 

I used one of those remote hose clamp things, the ones that are cable operated, to get the connectors off

 

Yeh I thought that might have been the case, but even still, seems like a MAJOR pain in the arse! I left it in the end yesterday just in case, looks like I'll have to wait for the rain to stop before I attempt it again!

Gocha! Sounds like that could help as well, though I think getting the hoses off looked like the easiest aspect of the job!

 

that was the hardest part, i needed 2 hands to pull the pipe off, but then another hand to use the clamps

after 4 hours of struggling and swearing my dad wandered past and i got him to hold the clamps

then it was a 5 minute job replacing the housing and then putting the pipes back on again

the bolts are easy to get to with a small ratchet and the wiring plug is also a doddle to remove, it's just that hose clamp as you have to bend the pipe to get it over the lip in the plastic before it'll come off and the same in reverse

if the front slam panel wasn't in the way it would be but a moments work

 

Yeh, was going to mention this but forgot! The sensor isn't built into either of my units... Not sure if this was something that was different on earlier STs or?

 

if it's not in the unit fitted to the car then it's not an issue

if it is then obviously it is

 

Obviously, but my point was that you may be talking about the process on a vehicle with the thermostat in an easier place to access!

 

It's in the same place on the Mondeo with the same engine, and its just as difficult to do

If only I could have removed the front frame I could have done it in minutes

 

Yeh that's it! Well, I seem to have bigger, gearbox shaped problems now to top it all off, so thermostat can wait! xD