So my FBH seems OK and runs when driving, however when i use the park heat function have now got this interesting noise coming from the wheel arch...

https://youtube.com/shorts/B7mZIyMJPRQ?feature=share

I am guessing it's the bypass valve that diverts tyhe FBH to heat the cabin but welcome any other suggestions before i start stripping out the wheel arch liner !. L322 2007 TDV8 3.6

First just try to touch this valve by fingers and then you can feel "clicking" coming from this valve or not. And check the plug at the same time, it looks like some bad connection with this valve.

OK so I replaced the changeover valve (fiddly ) and the problem persists !!! So got the battery and tray out and I believe that there is an airlock as the noise is coming from the coolant pipes into the FBH. I suspect the coolant is getting so hot its effectively boiling. Ran the WTT test software and all the components seem to be testing ok, including the FBH water pump.

So have run through the coolant bleeding procedure again, plenty of hot air coming through into the RR with the engine up to temp.

Now have to wait for it all to cool down to test the FBH again.

I don't think the FBH is at fault, it was running whilst driving the RR (i took out the boot floor panel and could hear the fuel pump ticking). It only seems to be a problem when it is used to heat the car up in the morning.

Any suggestions gratefully received. ! L322 2007 TDV8 3.6

Quick update… I think I managed to get out the airlock as the FBH ran ok when I retried 👍 L322 2007 TDV8 3.6

Be aware, water pump may get stuck sometime and no pumping (or pumping weak), and no error code at the same time due electric circuit is ok.