Antifreeze turns black

[Bear]

Hi I have a f32 with 1986 crusaders 350 the antifreeze turns black these engines were salt water cooled for a few years then converted back to fresh water cool , I flushed both engines with radiator cleaner put fresh antifreeze in, was clean for awhile then turned black again assuming its rust has anyone had this problem

[prowlersfish]

Most likely deposits from being salt water cooled . Pull the pipe plugs/ block drains on both sides of the engine ( black stuff settles there ) flush it out . fill with distilled water & coolant and a good ant-rust . may have to do it more then once . Good luck

This is assuming no other over heating issues . would not hurt to have coolant sent off and tested

https://www.walmart.com/ip/Gunk-C1012-1 ... 4=&veh=sem