Overheating

[blazer2020]

hi guys just wondering if i could have some help ? am new to this group well here we go i have a 2005 volkswagen polo 1.4 hatchback petrol today i just noticed that my cooling fan wasn't working however the car has never over heated i see the temp gauge creeping up the other day so switched the engine off and asked a friend for help i explained that my cooling fan wasn't working he suggested it could be the fan switch ? well today i replaced it with a brand new switch from euro car parts i fitted the new switch to the radiator today however my fan is still not working when the engine gets hot at least half way on the temp gauge i checked all wiring and coolant level all fine no over heating or loss of water also water pump is fine i also unplugged the cooling fan earlier and put 2 wires across the plug to the battery and the fan came on straight away now am lost for words would be much appreciated for any help at all cheers

[alexperkins]

Welcome

When you say the temp is creeping up, where is the needle getting to on the temperature gauge?

[blazer2020]

Hello Alex thanks for your reply ? Sorry what I mean is if I start the car from cold it can run for about a good 25 mins before temp gauge is half way then it will stay half way for a good 45 mins to an hour then you will see the temp gauge creeping up slowly pass the half way as the fan hasn't cut in some times you feel it missing on 1 cylinder but that's due to a broken faulty ignition coil also some times when the temp gauge is half way and I give it a hard rev to about 4 or 5000 rpm you see a little bit of blue smoke from the exhaust then it clears it's self I have both hot & cold air coming from heater inside the car earlier I put a code reader there was 2 fault codes present 1 relating to the egr valve and another relating to a permant fault with the climate control I fitted a new switch on the rad this morning still hasn't made no difference fan only works when I bridge it across a battery

[alexperkins]

I’d think about changing the thermostat. It should be at operating temperature in around 5 mins of running. That could well be causing all your issues as your coolant isn’t actually flowing!

[blazer2020]

Thanks for your reply Alex yes I will look in to this a friend did mention to me about the thermostat but he asked if the heater was working in side the car is there hot air ? I said yes he said well there isn't nothing wrong with your thermostat then I said ok ? One thing I did notice with this car and I have only just noticed was the car suffered front a front accident previously before I bought it the car has air con but the cooling fan fitted only has 1 fan not a small and a big fan ? Would that make a difference in the over heating trouble I have or not ? Also would the thermostat stop the fan from working ? 1 other thing I did notice earlier was the radiator it's self wasn't very hot ?

[alexperkins]

Heater and the thermostat aren’t related. It’s two seperate circuits

If the radiator isn’t hot it’s almost certainly the thermostat as the coolant will never circulate through the radiator and just gets hotter and hotter in the engine block

Also if you have air con you should have two fans rather than one so you have another issue there in itself

[blazer2020]

Ok Alex thanks for your reply ? I will see if I can go and grab a thermostat tomorrow I will keep you updated as to how I get on ok ? Thanks for your help tho much appreciated pal cheers speak to you soon

[RUM4MO]

Just one maybe wrong wild thought, maybe but that age of Polo, instead of 2 fans there was just 1 fan with 2 speeds and it is the slow speed that is now not working - did you get instructions on how to check both the slow and high speed operation of that fan?

Typically with a 2 speed fan, it is the slow speed that fails as the voltage is dropped over a resistor and that fails.

All of that assumes that that car was built with a single two speed cooling fan.