Fiesta heater valve

[Bren]

Replaced the above on my other half fiesta yesteday, did a quick check afterwards and it seemed to work ok.

 

However, wife used it today and problem has returned - constant hot air, but now the a/c is 'nt cooling either - i hear compressor click and electric fan run but no cool air comes from the vents.

 

Any pointers?

[Norbert]

These can be a bit of a bugger to bleed after doing a valve and if the air isn't 100% out it can go back to doing oven impersonations. From what I remember it pays to have the car jacked up so the air can all escape post replacement.

[Bren]

I drained the system then jacked the car up so that the expansion tank was highest.

 

Using a cut down pop bottle I refilled the system, however it is still the same - all the hoses are hot, initially I revved the engine and the heater went cool, but then hot again. That told me that there was air in the system, however I am now back to square one.

 

Very pissed off now.

[PiperCub]

Don't know if this is possible but is there any way you can raise the expansion tank to a point higher than any part of the engine? This can help with some cars.

 

Alternatively, try filling the system with the heater top hose disconnected, reattach it when coolant flows out so the heater is 'full'. That normally helps.

[Bren]

Bit of an update.

 

I drained the coolant and moved the header tank so that it was higher than the matrix/valve.

 

Refilled the system and got it nice and hot - all the pipes are hot.

 

Even on the cool setting, there is still hot air coming into the cabin.

 

I checked the supply to the solenoid - there is 12 v constantly, even when moving the knob from cool to hot ( I thought there might have been some kind of variable resistor on the panel).

 

Other than a faulty valve I am now stumped.

 

Any techs/ auto sparks got ant advice?

[beko1987]

Was it a bojack heater valve or a genuine ford one?

 

When mine went on the Puma (same part) I was warned against pattern ones, but a mate grabbed me one from allparts (cant remember the make). Broke after a week. £26 at ford later, and it outlasted the puma, when I fitted it to swmbo's cousins fiesta where it did another 10k before he got rid of it due to again, rust!.

 

I think it's a case of 'pay more for better'.

[Bren]

It was a pattern £25 item but came with a 12 month guarantee.

 

It seems that pattern spares really are poor quality - if they get much worse secondhand/ main dealer may be a safer bet. Probably made in Uzbekistan or somwhere similar.

[beko1987]

I didn't believe it until it happened to me.

[Ghosty]

What kind of Fez is it? Mk4/5s have shit thermostats and it could well be that.