Messages

16

VW Water Cooled / Lukewarm Response From Golf Mk2 Heater

« on: September 25, 2004, 03:54:55 PM »

Drained coolant, flushed radiator...all clear...removed old heater bypass valve and the heater outlet hose (leading to the black valve) was completely full of what can only be described as small, brown pieces of glass like chalk.  It looks like the black valve was also furred up by the same stuff (I do live in an area with a high chalk content in the water).

Flushed heater pipes to remove all the gunk and also reverse flushed the engine.

The heater appears to be working fine now but in the course of doing the above I noticed the following when running the engine up to normal temperature (12 o'clock on the gauge):

1. The top radiator pipe was hot and fully pressurised but the bottom radiator leading pipe leading to the water pump / thermostat was cold and appeared empty.  All other coolant pipes where hot.

2. The radiator fan did not kick in at all and, come to think of it, I can't remember the last time that I heard it work.

I changed the thermostat about 18 months ago and do not appear to have any overheating problems.  Is the cold temperature of the lower radiator hose normal and would this effect the operation (or lack of it) of the radiator fan?

17

VW Water Cooled / Lukewarm Response From Golf Mk2 Heater

« on: September 23, 2004, 05:57:31 PM »

Have taken the plunge and ordered a new heater bypass valve from VW...cost approx £30 but GSF don't appear to sell them.

Will drain and flush cooling system this weekend and then fit new valve...even splashed out on new antifreeze but provided I am able to keep warm this winter...priceless.

Will let you know how it goes.

18

VW Water Cooled / Lukewarm Response From Golf Mk2 Heater

« on: September 21, 2004, 09:02:15 PM »

Regarding the supply and return hoses, only the hose on the left (looking from the front of the car) with the black plastic valve is cold. The right hand hose with the metal valve appears to be ok.

19

VW Water Cooled / Lukewarm Response From Golf Mk2 Heater

« on: September 21, 2004, 06:09:15 PM »

Done a little more research on the above today.

Having got the engine to the normal temperature...five mins to first white line and then another five to get to the central red led...I checked the warmth of the hoses.

All of the hoses were hot except the supply and return hoses to the heater matrix. To be more exact, the hoses where only mildly warm above where the heater bypass valve has been fitted.

In view of the above would any of the following be the likely cause:

1. Air blockage in the heater matrix pipes preventing coolant from entering.  It states in the Haynes manual that the heater controls should be set to maximum when draining the coolant system.  If this was not done correctly would I get an air blockage and, if so, would simply draining the cooling system fix the problem?

2. Blocked heater bypass valve...replacing would presumably rectify.

3. Dodgy temperature sender unit / thermo switch.  Not really sure what this does but saw it in the Haynes manual???

Any comments regarding the above would be greatly appreciated.