Temp Gauge reading on Mk2 8v Digi

[6foot6]

Just been out in the snow, trying to sort this, the rad fan seems to kick in when the temp gauge reaches 1/4 (the 1st notch) if i up plug the fan and let it tick over and when the gauge reaches 1/2 and I plug the fan back in (MFA oil temp 88-90) the fan spins in its "boost" mode untill the gauge gets just under half way then reverts to normal speed then cuts off at 1/4.

Im starting to thin the rad switch is comming on to early - the STAT is new , dont believe that that is faulty

[rubjonny]

thats deffo not right, fan should kick in on slow when temp gets to about 3/4, which is well over 90degrees oil temp.

normal running when driving about the gauge should sit at half way, no matter what. if it reads colder the stat is opening too early, assuming the gauge isn't under-reading.  If the dash temp and oil temp agree then that goes a ways to confirm the readings are correct and you have a problem elsewhere.

thing is tho, the fan can do what it likes, but it shouldn't bring temps bellow 1/2 as the stat closes off coolant flow thru the rad at this stage.  I wonder if your coolant & oil gauges are both under-reading somehow, maybe due to a dash fault?

try checking the Voltage stabiliser:
To test the voltage stabiliser, connect a voltmeter between the terminals shown (see illustration) with a 12 volt supply to the remaining terminal. A constant voltage of 10 volts must be registered. If the voltage is above 10.5 volts or below 9.5 volts renew the voltage stabiliser.

[6foot6]

thats deffo not right, fan should kick in on slow when temp gets to about 3/4, which is well over 90degrees oil temp.

normal running when driving about the gauge should sit at half way, no matter what. if it reads colder the stat is opening too early, assuming the gauge isn't under-reading.  If the dash temp and oil temp agree then that goes a ways to confirm the readings are correct and you have a problem elsewhere.

thing is tho, the fan can do what it likes, but it shouldn't bring temps bellow 1/2 as the stat closes off coolant flow thru the rad at this stage.  I wonder if your coolant & oil gauges are both under-reading somehow, maybe due to a dash fault?

try checking the Voltage stabiliser:
To test the voltage stabiliser, connect a voltmeter between the terminals shown (see illustration) with a 12 volt supply to the remaining terminal. A constant voltage of 10 volts must be registered. If the voltage is above 10.5 volts or below 9.5 volts renew the voltage stabiliser.

Cool will do the check, where is the voltage reg located?

[rubjonny]

back o the dash clocks

[6foot6]

back o the dash clocks

Christ! will have to wait till the weather heats up, no garage   

[Alec]

Mine is the same, fan kicks in when the gauge rises above the white block (cold) and the oil temp is normal and reading 80-90.
I have never seen my gauge hit higher than a quarter temp even in the summer, and if it does the fan is going mental.

My engine was built by TSR and I am thinking they maybe put in a cooler thermostat cus they anticipated it getting ragged silly. Does that sound likely?

[rubjonny]

engine/stat temp makes no odds on the fan, the sensor for it is in the far edge of the radiator and it should only kick in when temp gets to about 95 degrees

[twistedblack69]

I don't understand the problem, mine usually sits between the big white block and the first line when I'm driving, is this a bad temp for the car to run at?

[Alec]

Problem is that the temp gauge reads alot lower than it should. As rubjonny says the needle should sit in the middle just like in any other car which is about 90 degrees.

[6foot6]

I don't understand the problem, mine usually sits between the big white block and the first line when I'm driving, is this a bad temp for the car to run at?

yes as the engine will possibly be running in the cold map and overfueling = less power and engine wear and Less MPG, if the oil is also at the wrong temp it will lead to excessive wear.

Engines run best 90 to 95 degrees C or in the case of Ford Zetec lumps even hotter (hence the thin oil they use)

I still cant get this sorted, I even put cardboard in front of the rad which gets the oil temp up to 80 -90 quicker and the temp gauge bang in the middle, but I have no heat from heaters now.

New Rad , new Thermostat

my clutch is gone in my MR2 (with its nice toasty heater) so at the moment Im driving about in a frozen Golf GTi and cant feel my legs or feet!

What does the bypass valve for the heater matrix do in the bay( how is it controlled?) if I remove it and replace with pipes (in and out feeds) will that get the heater going? or would it be the flaps under the dash that are goosed?