Start the engine and let it idle for a few minutes. With the engine still running, see if you remove the oil filler cap without too much effort .

I did this and noticed immediately that the cap appeared to not be screwed on properly (not leaking or anything, just screwed at an angle) so that was a good shout. I can still hear it but it does not seem as pronounced though it may be placebo. I'll keep an ear out for out over the next few days

is there anything else I should do or look out for?

Edited by CarlCar on 25/06/2024 at 20:58

Unfortunately, I drove it a bit this morning and it is still making the pumping sound. Oil filler cap comes off without too much work so appears to be fine