Draining coolant from a closed loop 6.0

[j2nh]

Did a search and didn't find anything.
What is the easiest way to drain the antifreeze (dexcool orange) from a ZR closed cooling system? I'd like to switch coolants, heard nothing good about Dexcool, so I'd like to get it all out.
TIA

[john_keck]

Hmmmm, not sure about the easiest way - I had to pull the starter off to get to the lower drain point on my 2006 ZR6. It was doable but difficult given the amount of space.

[agarabaghi]

PCM manual has instruction on how to drain a zr450 does that help?

[j2nh]

I will check the PCM manual and see where that leads.

Thanks john_keck and agarabaghi. Here's hoping I don't have to pull the starter.

[jkallen21]

FWIW - I have a closed loop 2006 ZR6 and have never had a cooling issue.

[j2nh]

FWIW - I have a closed loop 2006 ZR6 and have never had a cooling issue.

Neither have I but new coolant after 5 years is good preventive maintenance. I would like to switch from DexCool as I have not heard good things about it.

[d_nodixon]

What bad things have you heard? Changed mine a while back, bout to change it again. Don't recall the steps, but it was not hard to do. The pcm manual was my guide. Be sure to check the anode and inspect the heat exchanger.

[j2nh]

From a 2008 class action lawsuit:

"The lawsuits were filed on behalf of owners of General Motors vehicles, which were factory-filled with "Dex-Cool" coolant. In summary, the lawsuits alleged that Dex-Cool degraded certain vehicles’ intake manifold gaskets and other engine sealability components, and that in certain other vehicles, Dex-Cool formed a rusty sludge, clogging the vehicles’ cooling systems and causing vehicles to overheat."

[ericchile]

I posted the same question last year when I changed mine.
http://www.planetnautique.com/vb5/fo.../27843-dexcool

After some research I believe I remember figuring out that two things have occurred. The dexcool in it's original formula had problems with the head gaskets that GM was putting in their motors.

1) I believe the formula has changed after determining the problem.
2) Also PCM said that their head gaskets are not affected. That is was combination of the original dexcool and certain head gaskets.

It has been a while but I used this brand
http://www.amazon.com/Zerex-ZXEL1-DE...ywords=dexcool

My Nautique dealer said they are using dexcool still as well. Please confirm everything though!

[jhersey29]

From PCM website on the FAQ page : "For Model Year 2020 and newer, use Propelene Glycol (green in color). For previous years use DEX-COOL (pink/orange in color). I have ordered a new ZR409 to replace my GT40 and get ZO, etc. I imagine the engine will show up without AntiFreeze but not sure. Since it's a new motor would it be a 2021 or does it fall under the older motors since the 6.0 is actually an older engine? Does seem like green is the safest way to go.

[ESP]

Easiest way to change with out making a mess get 6 ft 5/8 heater hose run the hose through the drain under the boat, pinch the heater line from the motor turn off the tap remove hose, install heater hose run through the floor have someone manage the tap run into antifreeze containers, zero mess.

2020’s run poly propylene glycol it is green yellow and if you have leaks goes neon under black light.