No its deffo not pinking. the clicking is a fast clicking as if the speedo cable is slipping in the clocks or something.

but why this problem has come at exactly the same time as this air leak noise is beyond me!! probably just coincidence!

But as mentioned, i sometimes just have the clicking on its own and if i push it beyond 5k, it dumps air! but when it does, the air continues to come out for a bout a minute! and then wont run properly for a small period of time (usually after stalling!) so im deffo thinking the dump valve!