Slight burning oil smell today, oil all along the injectors and wiring and underside of cooler only on the left bank and finding its way backward to the exhaust manifold, doesnt look like the rocker gasket, is there anything else along there that can leak oil?

 

The cam cover is the only thing I can think of that can leak oil that high up. Check that the part load breather isn't plugged and causing pressure to build. Plenty of info here, just do a search.

But why have you eliminated it as a possible source?

 

There isnt very much oil along the gasket line of the cam cover but lots on the injection wiring and injector plugs and loom support rail and along the underside of the cooler. the last issue it had was a borewash non start which was sorted by lifting light oil in a tube and blowing it down each bore, sorted it immediately, but never got a long run til last week, 600 miles and the only problems being this annoying leak and white lines tugging at the steering! The only thing in the back of my mind is that it had an engine change because of an overheat and holed piston, not sure if the coolers were checked for oil from that trauma or if the new engine kept its own coolers! It was the left bank that had the problem!

 

The only thing besides what RJ mentioned that I can think of is that it's easy to spill oil while trying to add to the engine and will end up where the injectors are.