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Model specific boards => Golf mk2 => Topic started by: jimojameso on 30 November 2009, 14:32
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Hello guys
Got another problem with my mk2 gti 16v. It has been running fine for about three weeks since i finished restoring it. The coolant starts boiling and coming out the expansion tank. The strange thing is though that this starts to happen slightly before the gauge gets to the normal operating temperature point.
I have changed the thermostat and i am pretty sure there is no blockage in the system. You can tell the thermostat is working ok as the lower rad piper is cold and then once it warms up you suddenly feel the pipe get hot.The belts are tight and the water pump spins freely with no play in the bearing. Do you guys think i need to replace the pump? Really am unsure what the problem is. The fan works fine.
Also the coolant warning light continuosly flashes even when topped up to the correct level in the expansion tank. Is there possibly air pockets or in the sytem or does that indicate a lack of water pressure?
I really am getting stuck and is very frustating as i can't enjoy the golf at all at the moment. Just want this fixed now. Do you guys think it could be the pump? :cry:
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is it leaking through the cap on the tank?
Dan
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Is it boiling - or just a nasty air lock?
The cap is designed to release pressure at a certain level - so it might be dead too.
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Thanks for quick replies. Its boiling.
Its not coming through the cap but coming out somewhere else on the tank.
:cry:
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If the thermostat is opening as it should, there's no way it should be boiling
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Just taken the cap off and looks like the seal is screwed. I'll try a new cap first i think.
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i had this, water gets past the knackered seal and comes out a little hole in the tank.
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get a genuine cap from vw mate i got one off ebay and it was crap :wink:
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I doubt your cap is faulty
Air pocket in your rad and heater matrix.
Use VW G12++ coolant
flush the heater matrix and then the radiator out with both pipe ends disconnected. Reconnect then flush out any other air pockets.
Dont use the cheap concentrated coolant you find in halfords. I had the same problem for mine for a year because of the cheap stuff. It just boiled over all the time
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Do you guys think it could be the pump?
Hi
You know the small hose going to the coolant bottle, can you see water moving in it towards the bottle when the engine is running ?
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Try looking at the level sensor as Ive had several cheap ones fail and let water through where the pins go in (the pins then start to move lol). Otherwise as above.
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Hi guys
Thanks for all your replies. I have just flushed the radiator through and the heater matrix. Put all new coolant and replaced the cap with a new blue one from euro car parts. So far so good. No coolant loss at all. Gonna drive it all the way to work tommorow which is 40 miles so that will be the real test! Looks like it was that seal on the cap.
However coolant light is still flashing although seems fine now and coolant level seems correct. Any ideas?
:smiley:
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Hi guys
Thanks for all your replies. I have just flushed the radiator through and the heater matrix. Put all new coolant and replaced the cap with a new blue one from euro car parts. So far so good. No coolant loss at all. Gonna drive it all the way to work tommorow which is 40 miles so that will be the real test! Looks like it was that seal on the cap.
However coolant light is still flashing although seems fine now and coolant level seems correct. Any ideas?
:smiley:
Wouldnt worry about it too much the sensors tend to have a mind of there own after a while, when i changed the coolant in mine it started flashing randomly, i just ignore it now.
Dan
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Ha ha ok cool thanks Dan!! :grin:
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my light flashed for 8 years, pissed me right off, Didnt matter what i changed, Then someone told me 2 remove relay 21 in fuse board, Never flashed since and gauge still works, SORTED :grin: :grin: :grin:
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disconnect level sensor plug, bridge the pins. if that stops it, remove level sensor and clean up the pins. if that still doesnt help new level sensor is required. If bridging the pins doesnt help, its either wiring, clocks, control relay or the temp sensor.
beech, wasnt relay 21, thats for your indicators/hazzards ;)
level sensor control relay is #42 or 43 :)
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Thanks guys will try and sort that flashing bulb tommoro!! :smiley:
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Hello guys
I finally decided to try and stop that stupid coolant light flashing tonight. Its driving me round the bend.
Rubjonny your right relay 21 does the indicators/hazards. Tryed that one.
I couldnt find a relay 42 or 43? Are these in the fuse box under the dash or somewhere else? There are however a few empty slots under there but that bloody bulb keeps blinking!!!" ahhh!!
Please help.
Cheers
James :smiley:
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42/43 relay is clipped above the fusebox in a separate relay holder, but its only fitted to pre-90 MK2s (hazard switch on dash) and those with a 'digifiz' dash. 90spec models the coolant warning is all built into the clocks.
try disconnecting the yellow/red wire from the sensor on the side of the head, if light continues to flash its deffo the level warning circuit or the clocks at fault. If it stops, chances are its the sensor thats bust. try connecting the red/yellow wire to one of the other 2 sensors, see if the light comes back.
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Thanks John i was waiting for you to come to along! A wealth of knowldedge.
My car is a 91 hence why i couldnt find it. I'll have a look at the wiring to the sensor.
Thanks :smiley:
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Ok, i have got the haynes manual,It is for cars from 1984 -1992,
In it on the relay page it says that relay number 18 is for, (control unit for coolant shortage indicator)
It is located along side on the right of the spare fuses,
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yea trouble wi that is thats a pre-90 fusebox shown there, no mention of the 90spec one and its completly different! check the fusebox FAQ in the MK2 maintenance section :)