Technical Fan kick in time

[The younger modder]

Right after getting the car ready for mot i took it for its test yesterday morning and like when ive had it on the drive the fan doesnt kick in till 110 degrees which in my oppinion is too high, the mot man thought it was gonna overheat when he saw the guage keep rising and i said no dont worry it kicks in at 110 and it does so consistenly

the cars my 1997 Cinq sporting 1108 , i have fitted an 899 rad and fan if that makes any difference and they are in generally good condition, the coolant tank just has waterin currently as only put it in quickly the other day ready to take to mot but draing it soon and putting antifreeze/coolant mix with water in :idea:

now whats the problem? i think thermostat but my dad thinks im just randomly guessing , my old 899 fan used to kick in at 90 so could it be the thermostat kicking the fan in too late?

thanks in advance

wayne

 

[Cl@ssy Burd]

Mines EXACTLY the same, only had it since wednesday and it really worried me last night when it didnt kick in. Dunno wat to do

 

[arc]

thermostat could be jammed half closed. or it's a faulty fan switch. or you have an mahoosive air lock in the system.

new fan switch is only about a fiver, try that first - get some proper coolant in there and see whats what.

personally i'd think the engine thermostat not opening fully, so not allowing sufficent flow to the rad, and therefore it aint cooling it properly.

 

[Malin Dixon]

I assume that the temperature comes down once the fan turns on. If so:-

It's not your thermostat. If it weren't opening, the engine would overheat. If it were only opening a bit, the engine would overheat when a lot of flow is needed, which is when the engine is reving hard.

The problem is that the fan kicks in when the temperature on the guage is too high.

You have got one of three things wrong:-

1) The fan switch comes on at too high a temperature.
2) the guage reads high
3) the fan switch is at a much cooler temperature than the guage.

The last one can only be caused by insufficient water flow. I don't think that is the case because the engine would soon boil and the fan would cool the radiator, where the switch is, but not the engine.

No. 2 could be caused by a poor electrical connection. Have you checked the engine - body earth strap?

On ours, the thermostat opens about 10 degrees below the fan cut-in temperature, so the only time that the fan cuts in is when the car is going slowly and there is no air flow. If the temperature is constant when you are going above 30 mph, the thermostat is OK. If the thermostat is stuck closed, the engine will overheat when you go fast, if it is stuck open the engine will stay too cold when going at moderate speeds in winter, and the heater will be poor.

 

[Cl@ssy Burd]

Mines sorted now, kicks in at 90, had a huuuuuuuge air lock