So if anyone read this above with me trying to sort the knock sensor fault. That still progresses and I think it’s a wire to the ecu.
Anyway. During that work I replaced the after run pump that had failed. I got it all back together which is a big job taking the inlet manifold off. First run out I found a coolant leak. Traced it under the manifold so presumed I had knicked a pipe and didn’t know.
Took all the manifold off again today and the cause of the leak was the brand new after run pump. Leaking from the moulded seal. It’s a first line make. From speaking to a mate he had brand new T4 fuel pump fail costing 1800 is labour to put right after it failed.