Hi, Only recently (last week or so) the heating in my car has started playing up, it takes a few mins to warm up as normal, then after about 5 mins it starts blowing cold air out.

Someone mentioned that it could be air in my water bottle/pump. He suggested to let the car heat up, screw off the water lid, top it up and let it boil over (spill) twice then screw back on? Any suggestions? Thanks

N Plate - Corsa Diesel 1.7

TheBurf, October 2005

Simon,

That was exactly it mate! Thanks!

Thanks To Rob Too!

All in perfect condition again!

Thanks
Scott

TheBurf, November 2005

Find the thermostat. It will be an alloy casing on top of the cylinder head. It will have a rubber pipe coming off it to the top of the radiator. It will have one or maybe two sender units screwed into it. One works the temp gauge in the car the other switches the fan on. Take the wire off witch ever is the top one and unsrew and remove the sender. Now, start the car and watch to see if any air bubbles pop out the hole, try revving the while you do this. Be carefull when you replace the sender cause it may be a tapered thread and if over tightened will crack the thermostat housing if done to tight!! If this fails take off the two pipes to the heater matrix ( they go thru the bulk head) put a hose pipe on the bottom one and run plenty of water thru it. DO NOT take the header tank cap off and let it boil over!!!!! DONT bother with coolant system cleaner/flush either...... Waste of money. I have been in the motor trade for over twenty years and NEVER seen it do any good.

Simon., October 2005

Great Rob Thanks!

I will try that Today! - I don't think i have put anti-freeze into it for a while though and i didnt think that it would cause this problem , cos it actually does get hot, then just goes cold.

But i wil try what you said, thanks

TheBurf, October 2005

1. It could be the engine cooling system needs flushing.
2. Or your heater hot/cold valve is not opening properly.

1. Buy cooling system cleaner, and what some forget, ANTI FREEZE. to replace lost on draining. Follow instruction on cooling system cleaner packet/bottle. During final re-fill add the Anti freeze to the required/suggested strength.

2. If you haven't got a workshop manual go to/phone you local library and ask if they stock workshop manuals for vehicles, ours did, the fault could be the heat/cold control valve on the heater unit and it's a remove it job.

Rob, October 2005