454 closed cooling system

[kvando1]

I have what looks to be steam coming out of the exhaust on my starboard engine,and I'm losing antifreeze looks like trough the exhaust. Any help would be great.

 

[fastjeff]

Look at the gasket that seals the coolant from entering the exhaust system (in the manifold or riser). If that's not it, do compression test to see if a head gasket is leaking.

Jeff

 

[craig_collins]

+ 1 on what Jeff said. Hopefully it is the gasket/block off plate that's failing and not a head gasket.

 

[makomark]

I'd add that doing that inspection is much more effective when done while a pressure tester is connected to the heat exchanger; ie a pressure test...

 

[kvando1]

Look at the gasket that seals the coolant from entering the exhaust system (in the manifold or riser). If that's not it, do compression test to see if a head gasket is leaking.

Jeff

Is it possible that the elbows are bad.

 

[kvando1]

Is it possible that the elbows are bad.

 

[craig_collins]

Is it possible that the elbows are bad.

Do you have risers? If so, the elbows do not hold any antifreeze, only raw water.

 

[kvando1]

Yes I do

 

[erich]

The Crusader 454 had several models. Do you have center rise exhaust or log-style exhaust (at end of manifold)? It may make a difference in the placement of the block-off plate whether it is between the manifold and riser or between the riser and elbow. Check Marine Parts Source web site for diagrams.

When was the last time the risers and elbows were replaced?

 

[kvando1]

It's the log style..I don't know when or if they were replaced. It's a1979 I've have it for little over a year.

 

[hlssilverton]

I would say your elbows at least need to be changed! Any water mixed in oil? Did you remove any antifreeze from heat exchanger, if it has cross contamination from raw water will be discolored from antifreeze color.
I have 1992 vintage 454's and have done elbows every 5-6 years. Just had a bad heat exchanger so I replaced both.
Early symptom was steam and loss of anti freeze