Had no heating in my 2012 l320 ab for a while and it's cold now, was worried it was the matrix so flushed that today and noticed I'm getting no flow to or from it, car warms up OK doesn't over heat, bled the system and checked 10 times, anyone got any ideas. tia[/list]

Most likley just air locked if you flushed it try putting low pressure water threw it. Just disconnect x1 hose connect low pressure water hose and run it threw. Always worked on my P38 when I had same issue.

Not tried this, so disconnect the feed to the matrix and connect the hose to the matrix? Leaving the disconnected pipe open? Or cap it and open the resevoir

Leave it open the hose connected to the matrix will/should force any air out and after will/should befirced around the engine and come out from the open connector.

Does that sound right ?

I'll give it a go when the wife gets home with it, i was thinking it was possibly down to the valves by the fbh and on the opposite side if the engine, I'm certainly glad the matrix is clear. Thank you

It's worth a try 1st after that the valves is your best bet. Iv not going a diagram of the heater layout but if it's similar to my L322 the heater valve is a common failure point as is the small auxilary pump that pumps yhe water threw the valves and around the heater matrix.

Common failure on L322 iv replaced both on mine twice I don't suppose its that different on the sport

OK that didn't work, I decided to check the solonoid valve, I opened it up (without removing it as didn't have many tools to hand) and noticed the core wouldn't move much. Do you have any idea how much travel it should have? It spins freely but only moves a millimeter or so up and down. My guess is the o rings are swolen stopping the valve opening.

Is the pump the one just bellow this valve?

The valve should open and close fully if its only moving a mil its not working properly

If your valve looks like this
https://www.ebay.co.uk/itm/403612620140?mk...media=COPY

Mite be worth getting it does say 2013 onwards tho

Yes it's the same as that, I.was just looking at that one myself. I'll get it ordered

Nice 1, it's a simple swop out just pop the hoses off the old valve and connect the new one up you won't lose much coolant and can just top up as required.

Thanks I'll update by the weekend, hopefully it will be nice and warm in there again

So got the new valve, opened it up and checked how much the solonoid moved it was about 10mm, the one on the car moved about 2mm. Removed this and blew through the holes and it was closed on all ports, the new one had one side open. Swapped them and we have heat again. Now to try the fbh, I can hear it but no smoke and only cold air.

With the fbh try blasting compressed air into the air intake if you have that option to help get it going if its not run for a long time. After that gap tool to force a start or it's locked out after x amount of failed starts it will need resetting to work again.

So glad I'm running petrol only now

I just primed it and started it with my gap tool, working fine now after the neighbours came running out due to the smoke. Thanks for your help