Perkins 4108 rust stains on hull at exhaust?

[SailK2]

I've got a Perkins 4108 diesel engine with about 2500 hrs on her. She runs great but have noticed some rust stains on the hull where the exhaust gets discharged overboard. I suspect some sort of heat exchanger failure? I plan on taking the heat exchanger apart to do a thorough inspection after hauling. Anyone experience a similar problem?

Thanks,

Kevin

[capt-couillon]

Heat exchanger body is cast iron, hence possibility of rust stains ... Your water lift muffler (?) is probably glass, but older steel bodies can rust as well. Heat exchanger tube stack is usually copper bronze. There should be a "pencil zinc" mounted to the 1/4" drain plug on the exchanger. (Camp E-0 3/8" x 1-3/4") to reduce corrosion of the cast iron body. Many times the zinc portion of the plug assembly has corroded away completely and therefore not replaced. Would be my first check as an exchanger body is an expensive replacement.

Hope this helps

[Chasing Summer]

Don't know how your boat is set up but mine had a 3 foot peice of glavinized pipe as part of the exhaust from the builder. By the time I got the boat it was long rusted through. I would have hated to be at sea with it. I'd still be there only I'd be a submarine.