Hi all, on my most recent trip the landy has started making a noise that sounds like an old school fire bell. It doesn’t happen at idle or lower revs and seems to be coming from the near side. I can’t hear it from the front over the sound of the engine but it’s quite clear from the drivers seat.

Things I’ve tried/tested:
1) removed the auxiliary belt to rule out alternator/water pump bearings

2) checked exhaust for any looseness or rubbing, tightened all bolts

The engine is making normal power, and it happens in gear or in neutral on all of the boxes.

Any ideas?

(15j engine I think but definitely 2.5n/a)