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overheating
Posted: Thu Jun 04, 2015 3:40 pm
by darrenshaggy
hi there ive got a 1 ltr polo 1998
had no problems with it until today the car overheated went up to max ive checked to see if airlock but i did notice the big fan on rad didnt come on ive checked normal fuses all ok has any body any ideas please need the car for work thanks shaggy
Re: overheating
Posted: Thu Jun 04, 2015 3:59 pm
by alexperkins
Either:
A faulty thermostat (likely as these fail all the time)
A faulty fan switch in the rad
I would replace both, including the thermostat housing along with a coolant change
Re: overheating
Posted: Thu Jun 04, 2015 4:37 pm
by darrenshaggy
ware you say housing do you mean gasket or the complete housing if so whys that ??? thanks
Re: overheating
Posted: Thu Jun 04, 2015 4:38 pm
by alexperkins
Housing where the thermostat sits inside - it has a habit of breaking inside so the thermostat gets jammed. Its inexpensive and should always be changed if the thermostat is done, along with new gaskets.
Re: overheating
Posted: Thu Jun 04, 2015 4:48 pm
by darrenshaggy
how do i test the fan switch please
Re: overheating
Posted: Thu Jun 04, 2015 4:50 pm
by alexperkins
Youll have to check if the circuit closes with a multimeter - the problem is, its very hard to test that unless you attempt to overheat the car
The quickest diagnosis for this is see if the bottom radiator hose is boiling hot when youve been out for a drive. If its cold, the thermostat has failed.
Re: overheating
Posted: Thu Jun 04, 2015 4:59 pm
by darrenshaggy
ive let it get upto 110 the top pipe is hot and bottom pipe is cold so does that mean thermostat is ok but fan didnt kick in and also wen i but car heater on hot inside fans on temp drops to almost normal
Re: overheating
Posted: Thu Jun 04, 2015 5:08 pm
by alexperkins
The means the thermostat is broken and needs to be replaced
It means the water isnt circulating through the radiator
Get it replaced along with the housing (easy peasy) as soon as possible
Re: overheating
Posted: Thu Jun 04, 2015 8:16 pm
by darrenshaggy
went to eurocarparts got thermostat and the housing was £30 so i took that risk removed old one and yes you very correct that it normally breaks the housing but looked on line and you can just buy the coolant flange for £7 so i guess im going to gsf to get the new bit tomorrow many thanks for your help
Re: overheating
Posted: Thu Jun 04, 2015 8:24 pm
by alexperkins
Good news. It's best to replace the lot given how little it costs. Less chance of it failing again in future
Re: overheating
Posted: Thu Jun 04, 2015 8:30 pm
by darrenshaggy
this is true so i done me classic mini today so i can go n get the housing tomorrow lol thanks again