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Model specific boards => Golf mk2 => Topic started by: Judderi on 13 December 2005, 09:31

Title: More coolant problems
Post by: Judderi on 13 December 2005, 09:31
Lately my radiator fan has not been coming on and ive been overheating. Ive checked everything over and all is good. i.e the motor is working and the wiring is fine as when i bridge the pins on the temp sensor plug the fan comes on. That would make you think that its the thermostat thats nackered. BUT if i take the filler cap off and fill up to the marks on the header tank with the engine running and massaging top and bottom radiator hozes, the engine gets up to temp (bout half way on guage) and the fan comes on! But as soon as i put the cap back on and go for a drive the fan stops working again and i overheat.

The only thing i can think of is either the thermostat is intermittently faulty. Or its because i have filled up purely on tap water with no antifreeze. Will this make any difference?

Any ideas people. How do you usually fill up your coolant? i.e do you leave the cap off with the engine running until the fan kicks in then put the cap back on?
Title: Re: More coolant problems
Post by: silkyballs on 13 December 2005, 09:40
dude correct me if im wrong but change the cap it has a thermostat in the actual cap a mate had it happen to him and the one and only premier fixed that for him there and then as we spoke to him.see they can be could for sumik?????lol hope this helps dude
jamie
Title: Re: More coolant problems
Post by: rubjonny on 13 December 2005, 10:05
You mean the thermo switch in the rad don't you ;)
Aye as silkyballs said replace the cap with a new blue one as it is a better design.  There isn't a thermostat in it though, just a pressure release valve.

When you say 'it overheats' what actually happens, and where is the needle on the temp gauge?

If its only got pure water in there I don't think it makes too much difference though, I had to run it like that for a short while (to get me home) and it dodn't overheat or anything like that. Obviously you don't want to leave it like that overnight this time of year or it may freeze & pop out your core plugs!

To refil the coolant system:
Run the engine from cold with the cap off and rev it to 2k now and again.  While you are doing this squeeze all the pipes you can get your hands on, and keep the coolant level topped up.  It will eventually start to boil over, at this point turn the engine off.  Once its settled down top it up to the max mark and you should be good to go!

Check the lower rad pipe is stone cold until the temp gauge reaches the half way point, and that when it gets near 3/4 the fan kicks in.  If not jump the fan direct from the battery, if it still dont spin replace it, if it does replace the radiator thermoswitch.
Title: Re: More coolant problems
Post by: silkyballs on 13 December 2005, 10:23
ha ha i was close!smart arse!!!lol
Title: Re: More coolant problems
Post by: Judderi on 13 December 2005, 10:31
ok. Will see about getting a new blue cap and thermo switch.
Title: Re: More coolant problems
Post by: rubjonny on 13 December 2005, 10:37
well you did say 'correct me if I'm wrong'  :grin:
Title: Re: More coolant problems
Post by: silkyballs on 13 December 2005, 10:57
lol and im glad you did dude cos i have just learnt sumik new the same as you!!!and that is that i dont know what im talking about!lol.im learning all the time.my car has been one big learning curve dude.theres always room for more imformation in my head!
Title: Re: More coolant problems
Post by: Judderi on 13 December 2005, 13:57
get a room you 2  :grin:
Title: Re: More coolant problems
Post by: silkyballs on 13 December 2005, 16:59
ha ha he did mention it but i had to decline!lol :grin: :grin:
Title: Re: More coolant problems
Post by: rubjonny on 13 December 2005, 17:09
Your loss ;)
Title: Re: More coolant problems
Post by: silkyballs on 13 December 2005, 17:15
its ok its natural for you to feel rejected! :grin: :grin: