'97 Volkswagen Golf Problem

Hi All,
A friend dropped up last night in his newly acquired '97 Golf 1.4 - the interior heater's not working and it occasionally overheats...
So first of all I had a look at the water level - make sure he had some coolant in it - all was well there...
Next I thought it might be an airlock - so I ran it for a while with the cap off the expansion tank and massaged the hoses, the hose going into the heater matrix was very hot - the one coming out not so hot - but there wasn't a trace of warm air in the cabin...
The radiator was warm so I reckoned the thermostat was ok and hadn't failed shut, and the fan was cycling on and off...
Then something peculiar happened - when running with the cap off it would occasionally belch quite a bit of coolant out through the expansion tank - it would just surge up - and the temp gauge was showing around 90C at this time.. (the coolant was clean and not discoloured) - could the head gasket be gone in such a way as to fill the system with a burst of air now and then? (this happened maybe four times in 5-6minutes)
Is there anything else it could be? - the heater matrix is unlikely to be clogged it's a relatively new car and the coolant has been changed at some point... internally maybe it's the baffle or whatever it is that diverts the air over the heater matrix that has become disconnected from the control, but as to whats causing it so spit out fluid, I don't know?
In terms of water pump failures - don't they usually just start to leak, or just seize, it's unlikely to have stopped pumping leading to localised boiling or is it?
Any advice/theories appreciated,
Karl.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Karl wrote:

Sounds the head gasket. Had this on a Nova once - some mornings for about 6 months there was a psssshhhhh type noise from under the bonnet just as I started. Only on starting and only when cold. I could only imagine came from the expansion tank cap venting under pressure. Eventually one morning the head gasket went properly and started dumping coolant into the cylinders.
Similar story from somone who'd owned an old Viva (IIRC) - every morning the temp gauge would climb up into the red fairly quickly and, after a while, settle back to normal. Turned out to be a coolant/cylinder leak that sealed up as the block/head expanded, but when cold was warming the coolant by dumping exhaust gasses straight into it.
--
Scott

Where are we going and why am I in this handbasket?
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.