Disimilar metals or wrong antifreeze?

[tank1949]

I am servicing my older Sea Ray AJ that has closed cooled V8s. Salt water goes through the heat exchanger and risers only, not exhaust or intake manifolds. Intake manifolds are aluminum and stat housing is copper. All hose fittings inserted into iron manifolds are bronze. Motors have green antifreeze. I noticed green ooze or almost crystilized green stuff around the base of the stat housings where they are bolted onto the aluminum intake. I suspect dissimilar metals is causing this mess and there really isn't anything that I can do? Or, should I replace the green antifreeze with something else?


Thx!

 

[GA_Boater]

Copper exposed to moisture turns green and makes a crystalline looking mess. A gasket is probably dying and it would still be green with yellow AF.

You sure do have mix of metals. What brand are the motors.

 

[Scott Danforth]

Pull apart, flush system, clean gasket surface, replace gasket, refill.

AF needs to be changed every 5 years as it become acidic. It happens faster with the plethora of dissimilar metals. I would suggest flushing and moving to a newer HOAT antifrease

 

[crazy charlie]

Not to be concerned.That is just some AF residue.Many bell housings will have same creeping down the water passage hose.Cant remember not having it.Charlie

 

[charleso]

With the aluminum intake be sure to use an extended life antifreeze, not the old style conventional green. It can be harder on some plastics. It can make them brittle. However, it will not react with the aluminum and other metals like green antifreeze can. The residue you see is the product of this reaction. Use a good flush and clean the system and refill with properly mixed extended life antifreeze.

 

[tank1949]

System is now 100% flushed with new HE zincs, new stat gasket and new universal antifreeze. Increased bonding too!