Change antifreez

[Michael Mirra]

I have 2002 8.1 horizons. I have the boat for about 5 years now trouble free. Should I be changing my coolant.

 

[radscoot]

It Would be easier to test it first with one of these.
https://www.amazon.com/Performance-...75716056&sprefix=antifree,aps,137&sr=8-2&th=1

 

[Skybolt]

Five years for gas engines isn't that bad. It's diesels that need to have it changed often.

But you should always be checking it's concentration when ever work is done or adding water etc. But if your wondering if it's time to change it, look at the color if it doesn't look dirty from the new, then your good. But if it looks dark and rusted then yes, it's time to change. Knowing if the concentration is correct or not doesn't tell you if you need to change the anti-freeze.

 

[mrsrobinson]

If no service history on it and it "makes you feel better"; yes.

 

[scoflaw]

It becomes acidic after the years go by dealers recommend changing it at 5 years

 

[Michael Mirra]

Where is the drain plug located?.

 

[highslice]

Where is the drain plug located?.

My mechanic told me to use a fluid extractor from the coolant tank. I ended up having him do it last year because I didn't have time. That was 14 years with the same antifreeze. 415 hours on the 8.1 when the change was done. I tested it every spring and fall to make sure it was still good.

 

[GirlyGirl1999]

Sorry to take this thread on a detour but what about the GenSet? Mine is still bright green and full, but I haven’t changed it since we bought the boat 03/21
Jon

 

[scoflaw]

Where is the drain plug located?.

On the block midway just above the oil pan and below the exhaust manifolds, 1 plug on both sides. Coolant tank draining will only get the reserve AF.

 

[highslice]

My mechanic told me to use a fluid extractor from the coolant tank. I ended up having him do it last year because I didn't have time. That was 14 years with the same antifreeze. 415 hours on the 8.1 when the change was done. I tested it every spring and fall to make sure it was still good.

He told me how to get all the AF to the tank after draining the tank initially. But as soon as I decided to have him do it I immediately forgot it.

 

[Skybolt]

On the block midway just above the oil pan and below the exhaust manifolds, 1 plug on both sides. Coolant tank draining will only get the reserve AF.

Also some engines the exhaust manifolds are also FW cooled. So drain plugs at the bottom of them as well.

 

[mrsrobinson]

That's the way it was set up on my 330 with twin 7.4's, full system.