running hot

Is it actually going past the 3/4 mark? I had an issue with the temp switch on mine so it could be that but mine just got hotter and hotter until she boiled over.

Also is the fan cutting in? Lastly has the coolant been changed recently and are you sure it's full? I flushed mine the other week and had real issues making sure the system was full and devoid of air air pockets. Check the bottom hose on the radiator is getting hot too as if it's not the fan may not come in.

Tian

Also check your expansion tank hasn't sprung a tiny leak around the side or top seal edge (I've known one to wear away on the side where the bracket rubs against it over time). Mine kept losing water gradually so I put on another (2nd hand) tank on and it's perfect now. Although mine wasn't over-heating despite losing coolant, but yours is a different engine and the overheating could therefore be due to losing too much coolant. And it could always be that combined with your fan not kicking in at high temperatures like Tian says? As far as I'm aware it should kick in at just over the half way mark.  :dontknow:

tian wrote
Also is the fan cutting in? Lastly has the coolant been changed recently and are you sure it's full? I flushed mine the other week and had real issues making sure the system was full and devoid of air air pockets. Check the bottom hose on the radiator is getting hot too as if it's not the fan may not come in.

what is the likely problem if the bottom hose is not getting hot ?

i just flushed the system and the bottem hose still isnt getting hot
any ideas  :dontknow:

Are you sure it's full? I had to fill mine from the expansion cap and the top of the radiator too. then run it with the expansion cap off and fill until it reached the right level.

Basically if the thermostat was working before it should be working now. Let it warm up until the fan kicks in at around half way. If it doesn't kick in and it simply gets hotter. turn it off, you have an air pocket in the system.

Tian

nice one tian, didnt think it would be much wrong, whats the best way to get rid of the air lock ?
im gonna try again in a min with the manual in front of me this time

opentopvw said

nice one tian, didnt think it would be much wrong, whats the best way to get rid of the air lock ?
im gonna try again in a min with the manual in front of me this time

Take the bottom hose off and start again.

I took the bottom hose off and blew all the coolant out (don't suck)!. Once this was done and I was sure there was nothing left in it I replaced the bottom hose and added a premix of coolant and water to the top of the radiator making sure it was as full as possible. Then re-attach the top hose and fill from the expansion tank also.

Basically, fill it from as many angles as you can, run with the expansion cap off and top up or allow to flow over.

as for the manual, I used a VW Bentley's manual and it wasn't much help so good luck.

Tian

had another go, emptied then refilled everything , still the hose isnt getting hot, its a new therostat so dont think that will be the cause, but once its cooled down a bit i will take it off and check it by putting it in hot water etc just in case, dont think its the waterpump either as its not making any noises or leaking to suggest its the problem
any ideas  :dontknow:  :dontknow:    

I assume the fan isn't working then.

Tian

nope

opentopvw said

nope

The thermostat is probably fine but wont work until it has a reason and that's got to be because it's not getting hot due to a blockage/air lock.

It took me a while and I did get very angry with it but you will get there in the end.

To make sure there isn't a bubble of air in the lower reaches check the amount of coolant the system should take and check to see if you're actually getting this much in there, if not the answer is simple.

One final thing, I'm assuming all was well before you started the job and this was simply part of your winter service, is this correct?

Tian

well after redoing everything twice i decided to test the new thermostat with the hot water test and found that after being placed in a bowl of hot water for  few while it didnt expand so i think it may have been faulty ( halfords ! ) so gonna try one from europarts tomorrow.
 im presuming that if it is at fault the water will not circulate  :dontknow:

Tian wrote :
One final thing, I'm assuming all was well before you started the job and this was simply part of your winter service, is this correct?

no the car is my latest project and i dont know the history to it, but it was overheating before i started it, the head gasket is fine , the rad seems fine, engine runs sweet but one thing i noticed was a redundent water reseivour, as it has a top fill radiator, but dont think that will cause the prob  :dontknow:

 im presuming that if it is at fault the water will not circulate No idea!

True enough.

Tian

got back early today with a couple of new thermosat's, fitted it still no joy. so i decided to give the gti its winter anti change and new thermostat, flush the system etc, did it, started up ran it thru ,no problems. so its not me doing it wrong, which just leaves the water pump being the problem on the 1.5 gl as there is no water circulation
got a mk1 pump in the garage , just hope they are the same across the models as i cant remember which one it came off  :dontknow:
so will try that and let you know

Just a thought but are you sure you have got the thermostat the right way round?

I know on some cars (not sure about golf) it is possible to fit it both ways and if you get it the wrong way it will not open properly.

it can only go in one way

What about the fan, it's supposed to be a twin speed fan, can you check that's working by driving it direct?

Tian :wink:

havnt checked that yet, but dont think that would stop the water circulating. if i finish early enough this week i will change the pump as im sure thats got to be it

Hi
I've been having similar problems and just want to know who you got on in the end.
I know my fan works. I've flushed the coolant and replaced the thermostat but fan doesn't come on. Temp needle goes up to 3/4 mark but still no fan. Bottom hose cool top hose roasting.
By the way there's no expansion tank on mine (GL auto). Is that the norm? Last owner a bit DIY.
cheers
CC

I think I had an air pocket as well.
I ran the engine hot till temp light on, then took the rad cap off. The coolant began flowing after a slight delay and after a few seconds the fan came on itself!
Air pocket must have escaped. All OK now.
cheers
for the tips