help needed golf estate 1.9tdi

[golfowner1]

Hi all well i have a little problem my golf drives round town speeds no problems but when you motorway or boot it a bit it overheats and spit all out the expansion bottle and the heater goes warm and cold now would you think this is an airlock or a goosed heater matrix thats blocked any input would be greatfully recived

regards
mark

[zollaf]

water pump could have failed. is there any return flow to the header tank ??? could also be a head gasket.

[niall campbell]

could be thermostat in engine ........................................ this is your cheapest option first.

could also be a blocked radiator, which most folk forget about, especially with age of car , damaged fins .............. needs to be tested to check water flow.

could also be cooling fan/s not coming on. When car is overheated, are both fans running ?

Change thermostat first , then consider water pump ...................... especially if your due to change your camshaft timing belt at around £330

Another cheap option is change the expansion cap , a lot of folk again forget about this

To get rid of air locks, switch off aircon, put heater to hottest setting and turn fan up full , simply let car tick over for 10 minutes

[golfowner1]

Hi thanks for replies its had new water pump thermostat timing belt now heater is just cold air

cheers

[micheal balbrig]

As Zollaf says it may be h,gasket especially as overheating is present,and most other obvious causes ruled out