Author Topic: Coolant Problem  (Read 2870 times)

Offline jimojameso

  • Not said much yet
  • **
  • Posts: 68
Coolant Problem
« on: 30 November 2009, 14:32 »
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:

Offline Dan34

  • I live here
  • *****
  • Posts: 1,966
  • VTEC Powerzzzz
Re: Coolant Problem
« Reply #1 on: 30 November 2009, 14:34 »
is it leaking through the cap on the tank?

Dan

Offline Ben Lessani

  • I live here
  • *****
  • Posts: 3,873
  • The poor mans MK2 Haynes author
Re: Coolant Problem
« Reply #2 on: 30 November 2009, 14:36 »
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.

Offline jimojameso

  • Not said much yet
  • **
  • Posts: 68
Re: Coolant Problem
« Reply #3 on: 30 November 2009, 14:55 »
Thanks for quick replies. Its boiling.

Its not coming through the cap but coming out somewhere else on the tank.

 :cry:

Offline Ben Lessani

  • I live here
  • *****
  • Posts: 3,873
  • The poor mans MK2 Haynes author
Re: Coolant Problem
« Reply #4 on: 30 November 2009, 15:15 »
If the thermostat is opening as it should, there's no way it should be boiling

Offline jimojameso

  • Not said much yet
  • **
  • Posts: 68
Re: Coolant Problem
« Reply #5 on: 30 November 2009, 15:21 »
Just taken the cap off and looks like the seal is screwed. I'll try a new cap first i think.

Offline weazgti

  • I live here
  • *****
  • Posts: 955
Re: Coolant Problem
« Reply #6 on: 30 November 2009, 18:28 »
i had this, water gets past the knackered seal and comes out a little hole in the tank.

Offline raferackstraw

  • I live here
  • *****
  • Posts: 904
Re: Coolant Problem
« Reply #7 on: 30 November 2009, 18:35 »
get a genuine cap from vw mate i got one off ebay and it was crap  :wink:

wayne gardner smokes one rothmans too many
500cc 2stroke bad for ya health

Offline Mr Blue

  • Forum addict
  • *
  • Posts: 6,133
Re: Coolant Problem
« Reply #8 on: 30 November 2009, 18:41 »
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
:)

Offline mattkh

  • I live here
  • *****
  • Posts: 554
Re: Coolant Problem
« Reply #9 on: 30 November 2009, 18:54 »
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 ?