« previous next »
Pages: [1]

Author Topic: Strange coolant loss  (Read 1241 times)

rubberdubber

  • Guest
Strange coolant loss
« on: 02 February 2009, 17:25 »
Hi all

Having a strange issue with my Mk2 8v GTI digi, its losing coolant but there is no obvious leaks, its strange, you can top the coolant up to max mark.  Take it for a drive and get it nice and warm, pop the bonnet and the coolant will be well above max (normal expansion i think) but the right hand side of the expansion tank and inner wing all wet.  Leave the car for an hour or so to cool down and the coolant will be well below min again.  I replaced the expansion tank cap with a gsf blue cap about 4 months ago when i 1st got the car as it had a black one on there and i had heard bad things about them.  Do we think this GSF cap has failed and not sealing? maybe leaky coolant bottle? or something more sinister  :huh:

The car runs well, a little spluttery on 1st start up and the coolant pipes are hard when its hot but not overly compressed.
Logged

Offline Ben Lessani

  • I live here
  • *****
  • Posts: 3,873
  • The poor mans MK2 Haynes author
Re: Strange coolant loss
« Reply #1 on: 02 February 2009, 18:40 »
That amount of coolant loss should be pretty obvious.

Park it up on a dry day, run the engine up to temp at idle and just sit and watch the underside of the car until you see a drip?
Logged

Offline krave

  • GTI forum regular
  • ***
  • Posts: 176
Re: Strange coolant loss
« Reply #2 on: 03 February 2009, 03:35 »
If H/G was on way out would this not put too much pressure on the water, causing it to overflow and wet your inner wings, then when the car has stopped/cooled down due to the loss be low??

just a theory, or maybe a big air pocket?
Logged

Offline Conker

  • I live here
  • *****
  • Posts: 1,999
Re: Strange coolant loss
« Reply #3 on: 03 February 2009, 12:29 »
A few thoughts...

Leaky coolant tank/cap, or maybe one of the the coolant hoses going to it is leaking. As Ben said, it should be visibly leaking if this is the case. I once had a tiny pin-prick leak on the hose going to the top of the expansion tank that was only visible at high engine speeds (due to the higher pressure).

Over heating coolant would eventually force the cap to vent. What are your oil/water temps like?

Check the pipes going into the bulkhead to the heater matrix, maybe they are leaking and spraying the expansion tank as its quite nearby.

As already said, headgasket could be pressurising the coolant. Ideally you need either a compression or sniff test to confirm.
Logged

rubberdubber

  • Guest
Re: Strange coolant loss
« Reply #4 on: 03 February 2009, 17:54 »
hi all

cheers for replys, had it up in the air during lunch today, the radiator fan switch was screwed in finger tight!  :angry: well done previous owner who fitted that! So tightened that up, think it will be ok now.

cheers!
Logged

Offline sidecarphil

  • I live here
  • *****
  • Posts: 1,186
Re: Strange coolant loss
« Reply #5 on: 03 February 2009, 18:42 »
cool

easy cheap fix

love it :)
Logged
Pages: [1]
« previous next »