I have a bit of strange issue with my 52plate Mondeo TDCi which i have just noticed......

Starting the car from cold.............even if i leave it running for an hour the temp gauge does not rise more than i TINY bit......

But if i drive it, after a few miles it starts to climb but only a quarter of the way and the heater will be warm but not hot, even when set on High.

This is with the heater running..........If i turn the heater off the gauge will go straight upto halfway and sit there fine...........until i turn the heater back on, then it drops back down to about quarter.

Now the problem is that i am only getting about 33mpg round town out of my 2 Litre Diesel.......could this be because the ECU is only getting a reading that the engine temp is still low.....thus altering the fuelling/mpg.

What could the problem be???

 

My 02 plate V6 never went over half way with the heaters off, and barely got into normal with the heaters on, and that was in the two years i had it. heaters were not exactally hot either, so pretty much the same as yours.

 

could be the stat's knackered!

 

very strange..........

I just think this may be wh my mpg is a little poo........if the ecu see's a low temp it may alter the map slightly???

 

I did think stat tbh.....but the heaters work and all the pipes get hot ect......hhmmmmm

Could be a lazy stat

 

thermostat first mate

 

I've got something similar. 06 plate 2.2 ST TDCI.
Takes ages to heat up, will get to 'norm' temp but when i put the heater on it drops rapidly. It is damn cold at the moment so i'm putting it down to the heater drawing the warmth from the engine. If i'm motorway driving its them fine, but slow roads it backs off.
However, its getting 50/55 mpg on a run.
I'm not worring too much yet!?!?!

Hope this helps!

 

Exactly the same as mine.......but you get a few more mpg....but mine is just town driving....

Heard the stat is a right ball ache to do on these otherwise i would of done it on the off chance

 

Yeah, i'd heard the stat thing too... have a look at the stdrivers website, under the tdci problems section. There's two stats on the motor aparently.
What makes me think its the weather at the moment is that my car's only got 30k on the clock..
My mpg last week on town only driving was only 38 mpg, and that was below freezing all the time. But at the weekend I got 57 mpg on a 100 mile run!?!?!

It's a bugger!

 

Thermostat!! Had very similar problems on my old st170, new stat sorted it

 

HHmmmm......may have to find someone to do it for me then as its looks like a nightmare

 

temp gauge should sit bang in the middle once warm and stay there.. if it doesnt then one of the temp sensors is down! usually the rear most one.. and yes thats why you will be getting poor mpg.. sensor is about 12 quid.. just looked for the finis but to no avail..

 

Just a case of changing the sensor then Matt?????????

 

was on my old mans yes mate, bit of a bastard to do. I found a link on mondeo owners club on how to do it if i remember..
the differance in mpg was unreal...

 

Got the same problem with my st tdci atm... takes ages to get warm, will only get properly hot on a proper run and the mpg is down massively.

 

Mark mine always sat dead middle on the guage and did NOTHING else..... no matter how hard I drove it and no matter what ever the weather...

See if theres a fault on the diagnostic thing - its the same as the ST170

 

In fact I think on the diagnostic thing it tells you coolant levels

 

will try the sensor thing irst i think.........sounds the easiest to do.....

Jake.....tell me more

 

+1 mine dont move from the middle


Brian

 

there was a post up the other week about poor MPG on the tdci and i think it was the EGR valve needed cleaning and the MPG would shoot up

 

Yer there was....done all that

 

Its on the ST170 dot com thing....

Press Reset and start the car and it will go through a load of diagnostic options on the led read out.

 

I see..........you can show me sometime

 

Interesting... My mums TDCI 130 Mondingle has exactly the same problem, what you going for Tiff, the rear sensor or the stat' first?

 

Rear sensor first as the stat is a right pig to do by all accounts.......sensor is cheap and should be fairly easy...

 

I can understand it being a temp sensor if it was reading a steady, but wrong temperature, but as you say the gauge goes up and down with the heaters off or on, and the heaters are not very warm is definately saying thermostat to me!

 

Will do big man....

 

If all else fails, remember the old fashioned bit of card in front of the rad,

especially in this weather for a quick fix.

puddy

ps. turn the a/c off as this will run the rad fan as well when on

 

cheers for the help guys

 

Let us know how you get on as mine's doing exactly the same thing!

According to some people it could be normal

http://www.fordmondeo.org/forum/show...d/824313/tp/2/
http://www.honestjohn.co.uk/forum/po...ex.htm?t=80248

But this says otherwise and shows how to fix. Does look fairly simple (if a bit tight)

http://www.stdrivers.co.uk/forum/sho...arch/1/#112079

 

thats funny all the tdci mondeos are doing the same thing lol

my dads is doing the same and my one is too ..

let us know if you find out the problem .

i phoned ford to get a stat of them but they wanted £37 so i will try the spares shop tomorrow .

 

very strange

 

Brother changed the secondary stat on his and is loads better

Steve

 

Where is the secondary stat located???

 

my 2005 2.2 tdci mondeo st was taking about 3 miles to warm up . it started to take upto 6 miles had the stat replaced it is now taking 8 miles .Going back to garage will inform out come later

 

A faulty sensor wouldn't explain why the heaters dont get very hot though.

I'd try a stat first myself

 

hi i have a tddi mk3 with this exact same problem i am a senior tech for jaguar i have changed the coolant temp sensor which there is only 1 on all these cars also the thermstat neither has fixed mine either so dont do these i have however found that there is a coolant heater unit located at the rear of the subframe which has what looks like 3 glow plugs comeing out of it and it would appear is that when the car is warming up and the thermstat is closed it heats the coolant so that you have heating in the car and when the thermstat is open it switches on and off to regulate the heat as these engines are so efficient they cannot contain the enough heat in the engine to run the heater and the engine cooling at the same time. I am going to fit 1 to mine to see if it rectifies the issue and i will let you kno how i get on, ps the correct ristance values for th glow plus in this unit are 1.0 ohms if you cannot get a ressistance then thay are open circuit and therefore nackered.

 

As said there is a 2nd thermostat on the back of the water pump, it's only about £10 from ford and will most likely fix your problem.

welcome to the forum btw!

 

I can't remember if there is a similar set up on the Mondeo but on the 2l Transits, the water pump is driven off the back of the PAS pump above the gear box and the splines used to wear on them both. The steering would be fine but the water pump would lose drive and stop pumping water around the engine. When it got bad the CHT sensor would start cutting the engine out to protect it. Used to have to replace both the PAS and water pumps as both splines used to wear out.

 

What was the outcome Tiff?