Anyone ever replace your Dex-Cool anti-freeze in your 270fv w\ big block?

[dwb1957]

   There are times when I love the Big Block...but not today.  Boat is 5 years old, thought I replace my Dex-Cool in my Gen Set & the 496...Waisted about 2 hours trying to get at the drain plugs, or even identify them, so I could get the Orange Stuff out...I abandoned the project for now.  That motor is absolutely stuffed in there...Supposed to be Hex Head plugs, about 6" behind the motor mounts.  On the PORT SIDE,  I can see a painted Hex Nut plug AND a larger plug w\ a female square drive receiver (don't think that's the one)...When I checked the Starboard side, OMG, can't get my arm, mirror, & light in there to see a matching plug.  That's the side with all the hoses, batteries, etc.

Once again, I don't know how the marine mechanics do it.  They must be triple jointed.  Anyone have any advice?  Yea, let a shop do it?

[alswagg]

Why are you replacing it in the first place?  The Mercruisers recommend the Dex cool  antifreeze anyway.  Do you have a thousand hrs?  In the marine world you might not ever have to replace, only add every once in a while.   Al

[dwb1957]

My understanding is every 5 years on Dex-cool...

[alswagg]

It is more of heat cycles than it is time.  With the temps that marine engines run you may never have to change.  Remember a good ratio is 100 hrs is like 1000 miles in your automobile.   Al

[dwb1957]

Just an update for those seeking the same information I was...For coolant replacement on the Merc 496 mag has one plug on each side....The two hex plugs that also have the allen wrench inset, black painted w\ motor.  I used an 18MM socket & a 1/2" drive w/ 6" extension worked just fine.  Just under $40 DIY...

[Oldntired]

Go to a diesel parts supply and get some coolant test strips.  Test it and go from there.  It probably is fine.

[jmeyers278]

Just for future reference.....do a google search on problems with dex cool......I would recommend taking it out day 1.....that stuff is seriously hard on you engine and cooling system. 
http://www.consumeraffairs.com/news04/2006/08/gm_dexcool.html

that is just 1 of a thousand sites that tell you how bad it is.  I have personally had problems with a gm truck with a 454.....