I am having problems with my zetec running to cool, it rarely goes above 75c and tonight I tried to do a datalog with the megasquirt and got a log I
couldnt use, as the engine temp was below the warm up point most of the time.I was worried that the polo rad would not be up to cooling it as the
previous crossflow always ran quite hot.
I have plumbed it in correctly as far as I can tell with the thermostat housing to the top hose and the bypass connection below the top hose onto the
bottom hose at the water pump outlet.I blanked off the other small outlet which is usually connected to the heater as i could see no reason to run 2
hoses to the bottom hose if not using a heater.
I have not changed the thermostat so it may be that but i would have thought it unlikely.
I know this was a problem on westfields that had the bypass connected to the top hose but cant see any reason why my set up should run cold.
Paul.
I'd replace the thermostat as the first step, the FOMOCO ones are infamous for sticking open
I would agree that it is probably the thermostat as mine warms up nicely. I think the thermostat is set to open higher than 75degrees.
I am not sure about blocking off the heater outlet though as I am not sure of the passageways and flows inside the housing.
Are you sure that you have used easytherm correctly to ensure that MS is reading the temp correctly (sorry if that sound condescending)
How big is this bypass hose? I've had a simialr problem with older cars, when I fitted a secondary radiator to my mini's heater circuit. It went from running too hot, to barely on the gauge! It could be that there's enough flow to prevent the engine ever getting warm. Or the thermostat's fubar'd.
I have just been and bought a new thermostat so will try that this afternoon if it dries up a bit.I think MS is reading correctly as it matches the
reading on my capillary gauge on the dash , I used a bosch sensor and changed the bias resistor to suit it, although i do need to adjust the air temp
sensor as that reads out by about a few degrees .
Paul
quote:
Originally posted by TangoMan
I would agree that it is probably the thermostat as mine warms up nicely. I think the thermostat is set to open higher than 75degrees.
I am not sure about blocking off the heater outlet though as I am not sure of the passageways and flows inside the housing.
Are you sure that you have used easytherm correctly to ensure that MS is reading the temp correctly (sorry if that sound condescending)
The bypass hose is 1/2inch the same as the original installation and goes directly back to the waterpump, so should have no effect on the main cooling
circuit.
I could put a restriction in it though if a new thermostat doesnt do the job.
Paul.
quote:
Originally posted by DIY Si
How big is this bypass hose? I've had a simialr problem with older cars, when I fitted a secondary radiator to my mini's heater circuit. It went from running too hot, to barely on the gauge! It could be that there's enough flow to prevent the engine ever getting warm. Or the thermostat's fubar'd.
Thermostat!
if its shut, it can't overcool, so there's something wrong with it, fortunately simple as that!!!
PS have you put a thermocouple on the engine to see what its actually running at?
Not unusual for the injection coolant temp probe to fail and give your injection system the wrong values
Yes it agrees with a capillary gauge i have on the dash , thinking about it it must be the thermostat as the gauge is after it and always reads the
same as the megasquirt.Im going to change it this afternoon and hopefully i may get a chance to try it if the rain stops.
Paul.
quote:
Originally posted by NS Dev
PS have you put a thermocouple on the engine to see what its actually running at?
Not unusual for the injection coolant temp probe to fail and give your injection system the wrong values
It was the thermostat, changed it this afternoon now runs at about 85 - 90 and fan operates at 95 for a short time whilst standing idling.I can now
try and get on with tuning it.
Paul.
Yeah, it's a well known weakness on Mondeos, my Mondeo's was stuck open when I bought it. It's a bit slack on Fords part. But at least
it sticks open not closed 