Technical overheating:(

[Drinu]

HI everyone,
my uno is overheating.....its a 999cc FIRE engine. it all started last week. The fan does not kick in. I bypassed the switch and left the fan always on while driving and that solved the problem. Obviously after parking the car I would have to remove the piece of wire I used to bridge the fan connections.

Now last week I changed the switch. The fan now kicks in however, it only does so for around 5-10 seconds and goes off again. The temperature still went up to 3/4way of the guage. I have new coolant as well. Anyone know what the problem is? I never had this problem.

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[jason45]

It will most likely be the thermostat is away you can pick one a cheap enough had the same problem with my first uno cost about £6 from halfords.

Jason

 

[Drinu]

could it be the thermostat?I only changed that last year! If it was the thermostat I dont think the fan would kick in, in the first place. Am i right?

 

[Chas Uno]

Check the thermoswitch earth connection. You could have a poor earth hence the intermittent fan. On my mk1 the earth for the fan is on the 'hedgehog' earth block sited near the battery.

You could also check the plug that goes into the thermoswitch. If when you bridge the terminals the fan always runs then the fault lies with the thermoswitch. But if you get intermittent fan running then it's an earth problem.

Lastly, did you bleed the cooling system when you changed the coolant? An air lock can cause similar symptoms to those that you describe.

 

[jjhepburn]

I have had this problem with a themostat, it wasnt opening so water wasnt making it to the radiator properly. This happened to my Punto and the thermostat was only about a year old.

 

[Drinu]

here is an update...

I cant take the car to mechanic since its the weekend. Its due for tomorrow though(monday). In the meantime I bridged the fan connection so the fan is always on. Guess what the car still overheats. At one point it went up to 3/4 of the guage. I stopped on the side and let the fan cool the coolant a bit. after about 10min the guage was 5/8 of the way. I decided to start driving and as soon as I did the guage went down to 3/8 of the guage (less than 1/2). It then started to heat up gradually.

I dont know what else it could be? do u think it is the thermostat? Its definetely not the water pump as it is moving the coolant from engine to radiator!

 

[Drinu]

yaaayyy I fixed it. Twas a faulty thermostat and a blocked radiator....back to normal now!

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[Chas Uno]

yaaayyy I fixed it. Twas a faulty thermostat and a blocked radiator....back to normal now!

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[cotroler]

had exactly same problem, gauge went 3/4ths way and it was a blocked thermostat.. what i did i removed the thermostat and open it which means it will always allow water in... now gauge doesn't go higher than 1/4th of the gauge

i will leave the thermostat opened for this very hot summer, when the winter will approach i will change it as it will be difficult to stary in the mornings...

 

[Chas Uno]

had exactly same problem, gauge went 3/4ths way and it was a blocked thermostat.. what i did i removed the thermostat and open it which means it will always allow water in... now gauge doesn't go higher than 1/4th of the gauge

i will leave the thermostat opened for this very hot summer, when the winter will approach i will change it as it will be difficult to stary in the mornings...

This is not a good idea. The thermostat regulates the engine temperature so that it operates at its optimum temperature range, which is normaly between 80 - 90 degrees. If yours doesn't go above the 1/4 mark on the gauge that's about 70 degrees, which means your engine is not running as efficiently as it should. This will reduce power and increase fuel consumption.

An open thermostat will not make an engine difficult to start once the weather gets cold, but it will slow down the warm up process. This again reduces its efficiency and means you freeze in the cabin as the heater won't work!

A fully function thermostat will not inhibit cooling!

 

[alexGS]

This is not a good idea. The thermostat regulates the engine temperature so that it operates at its optimum temperature range, which is normaly between 80 - 90 degrees. If yours doesn't go above the 1/4 mark on the gauge that's about 70 degrees, which means your engine is not running as efficiently as it should. This will reduce power and increase fuel consumption.

:yeahthat:

In really hot weather (ambient temp 26+ degrees) or for race car use, you can get away with an open thermostat. Otherwise, just fit the new one now

-Alex