Kadey Krogen Manatee Heat Exchanger

[Manatee]

After hundreds of miles in my trip to get this little baby back home my engine has suddenly start overheating. We discovered a leak where the heat exchanger end cap meets the housing. The drawing shows there should only be 2 O'rings and one cover with fastener. In real life we have the above mentioned parts and a hard plastic sleeve that goes between the cover and the housing somehow. Is anyone familiar with this part? It's not in any drawings I've located. This is for the TMD30A Volvo Penta 90hp engine.

 

[bligh]

Are you trying to address the overheating issue or the extra piece in the cover? Or do you think you they are related? If so , how?
For overheating, you should first check your sea strainer, then your coolant level then your impeller. After that then the heat exchangers should be inspected.
I'm unfamiliar with your heat exchanger and the plastic piece, but maybe someone else is. A picture would be helpful!