Heater not working or intermittent and the engine is getting too wam
Is it thermostat or water pump.

 

air bubble?

 

Take the rad cap off, run it up to temperature, if you can see the water moving the pump and stat are OK.
If it's not moving, take the stat out and put it in a pan of boiling water, if it opens it's OK if not it's fubar.
If you do the rad cap off test with the stat out you will be able to see if the pump is working.

 

Thanks for the replies will try without stat and make sure it's bled well . Just a bit worried where the coolants gone. Can not see any leaks and None of signs It may be the head gasket. Just have to keep an eye on it. I will let you know how I get on.

 

If you've lost coolant then the radiator will start to suck in air through the expansion bottle. You've probably got a massive air lock in the coolant system now. I would be tempted to let it all cool down and rebleed the entire system and check again for leaks.

If it was going through the headgasket then i would expect a sump full of mayo or loads and loads of condensation out of the exhaust.

 

It's easy to get air locks on the S2. I've just had same after replacing rad switch and coolant. Initially no heater then after bleeding got heater hot for a while then goes warm. Then engine started getting too hot.

Check your top hose gets hot, if not stat stuck. I ended up bleeding the system with the funnel sealed in the rad and coolant bubbling up and down. Eventually got a big rise in coolant which looked like it would overflow, before it suddenly was drawn back in. After a few more runs around the block, stopping and then cracking of air past the bleed screw it was all sorted.

 

Maybe stating the obvious but do not drive this car until you get it sorted, sounds like an airlock to me as (others have said) an overheating F20c is a timebomb.

 

Park facing uphill and bleed from here:

That's what I did when I changed out the rad.

Hope that sorts it.

 

Thanks again to everyone. Refilled system with car front on ramps and bled (thanks for pic) no leaks heater working no drop in fluid. Just very concerned as it took 1.5 litres. Only had car for 8 months . Now engine management light is on. Going to buy an ODB reader a Clarke from Machine Mart looks like a reasonable buy. Anyone got any recommendations.

 

It's been said few weeks times, quickest and easier way to bleed this car successfully is Jack front end up rad cap higher than rest of engine, leave cap off and watch bubble come out and refill slowly.