Found out
heat exchanger is shot. There was red area around salt intake and tube feeding salt. Obvious electrolytic
corrosion. Found posts online that said everything from 4 pencil zincs in
cooling system others said none. One
plug in old heat exchanger looked like could have been zinc. After checking
Perkins marine diesel shop manual, shop manual and boats manual still no mention of zincs. The aftermarket exchanger was made by champ and is copper, manual says original was
aluminum. Well zinc or no zinc that's the question. New one ordered from inet boatsman
marine. Will be curious to see if zinc is installed.