Vetus P4.19 Exhaust problem

[jono63812]

Hi everyone, I have a Vetus P4.19 engine onboard, and for the last 10 hours we have been noticing what we believe is exhaust smoke filling the engine bay and the cabins, finally today we managed to get in and find a small hole with our hand by feeling air (exhaust fumes) coming out the side of the engine. Its round the back and tricky to photo well but see the photos below. One of where the hole is and one of the hole itself. The exhaust pipe and sea water out pipe lead off just below the hole, I believe the hole is on the part where the exhaust out and the water mix. The engine is perfoeming fine and is not over heating? Water is exiting the boats exhaust from the stern of the boat?

Any help with this would be great, confirmation on the problem of why it has occurred and how I could fix it. I cannot find parts list from Vetus to identify the part with the hole.....? Im kind of stuck..

Thanks everyone.