Golf Mk IV Engine temperature dropped

[mangoman]

Hi, i have a 2000 GOLF MRK IV 1.9 TDI 90 BHP, over the last week i have noticed that the temperarture showing has dropped form the normal 90 degrees to 80 degrees. It then may fluctuate a few degrees either way. Noticed the car heater is is not as warm as normal. Is this a problem with the thermostat ? If so, can I confirm this and can someone please tell me where it is located and how easy it is to change. Thanks.

[chris.fulton]

It does sound like the thermostat could be stuck open a bit if the temp is dropping below 90, it usually stays put even in the coldest of weather. Here's how to change the thermostat:

Please note that this only applies to the Diesel engines


Thermostat removal procedure

1) The thermostat is located behind a connection flange on the front side of the engine block, at the timing belt end.
2) Drain the engine coolant and remove the engine cover
3) Remove the securing clip and disconnect the coolant hose from the thermostat cover/connection flange
4) Unscrew the 2 securing bolts and remove the thermostat cover/connection flange completely with the thermostat. Note the location of any brackets secured by the bolts. Recover the O-ring if it is loose.
5) To remove the thermostat, twist the thermostat 90 degrees anti-clockwise and pull it from the cover.


Refitting the thermostat

1) Refitting is a reversal of the removal process but bear in mind the following points.

• Refit the thermostat using a new O-ring
• Insert the thermostat into the cover and twist 90 degrees clockwise.
• The thermostat should be fitted with the brace almost vertical
• Ensure that any brackets are in place on the thermostat cover bolts as noted before removal
• Refill the cooling system

[mangoman]

Thanks for the info.

I will not be able to tackle this till the weekend, in the meantime Is the car safe to drive ?

[chris.fulton]

Yeah it should still be OK to drive. If it was overheating then I'd say no don't drive it but since yours is overcooling then it'll be fine for a while.