Why is my anti freeze black

[Flying Colors]

why would my antifreeze be turning black if it has nothing else to do with the heat exchanger??

[lrc]

anti-freeze

More information?

Are you losing anti-freeze?

Have you checked your oil and/or changed it? Is there water in the oil?

Are you having any signs of increased engine temperatures or overheating?

Has the elbow on the exhaust manifold ever been changed or cleaned and regasketed? That's a prime failure point on older boats but is usually accompanied with overheat issues.

[Flying Colors]

yea the boat has been over heating when we slow bac down .
but the manafolds and risers were just repalced
also the oil is crystal clear

[outriggers]

Have a test done for exhaust content in the coolant. You may be able to get a test kit to do it yourself. If you have a leak of compression into the cooling system you should possibly see some bubbles at the filler/overflow. I believe I saw that you have the 8.1l engine. The one I have just installed feeds the overflow back into the heat exchanger. I assume it just returns to the system??? Remove the cap and then run it to warn up the engine and look for bubbles in the reservoir.

If you have a head gasket leak it will probably start to run a little warmer and when you shut it down or slow down you would probably get the temperature rise indication which would cause some overflow.

[Flying Colors]

well thats another thing we just replaced head gasketts last year and unless the were instaled wrong i dont think that they wold be leaking... where can u get that kit???

[outriggers]

Check your local auto parts store