[COLVERT]

Originally Posted by WillyHeckaslike

Sounds like you have air in the cooling system and with the lumpy idle, coolant loss etc I would suspect the IMG. Pull out the plugs and check if 1+4 look different.

I don't like to say this Poppy cos it's upsetting, but I think WHAS. is accurate with his opinion.

All of the symptoms you have stated point to the head gasket starting to leak water into one of the cylinders.
Also when the engine is running gas will enter the cooling system and displace some of the water and it is this gas you can hear flowing through the heater matrix and making that bubbling sound.

The light on the dash is not a problem. It comes up because your engine has been ticking over very slowly and the charge from the alternator has dropped away. Nothing to worry about with the electrics just the head gasket..
Why the plug in the leaking cylinder is not firing and is showing up wet is because of the leak.The slightly reduced compression in the cylinder means the plug won't ignite the fuel at tickover.
As you bring the revs up then the compression rises too and the cylinder starts to work. ie. the engine then runs smoothly.

However this state of affairs will only be short lived cos once a gasket starts to leak it progressively gets worse.

I hate to be, like Willy, the bearer of bad news and I hope Willy and I have both got it wrong.

Fingers crossed for you.


Colv.