View Full Version : LY6 Winterization

09-13-2011, 08:30 AM
Last year when I winterized I pulled the thermostat out after draining the engine, hooked everything back up and then ran antifreeze through the engine. There were different thoughts on whether this is necessary or not.

If I have drained the engine and have blown all water through the heater hoses...is there any need to make sure the antifreeze runs beyond the thermostat? Is removing the t-stat a good way to make sure the antifreeze gets everywhere? I don't fully understand how the cooling water flows through and bypasses etc.


09-13-2011, 09:15 AM
Indmar's method to LY6 Drain/Winterize

09-13-2011, 05:44 PM
Okay, that must a little older than mine as some of the components look a little different...but regardless, good information. I still prefer to run antifreeze through the engine just in case there is any water left over....our winters get pretty cold so freezing water is a big concern! :(

09-13-2011, 07:35 PM
Is it better to leave the motor empty or full of antifreeze? I have two dealers telling me that each one is better? Cold storage in ND. Thoughts? Same price for both.

09-13-2011, 09:43 PM
I wouldn't think that it matters a whole lot either way. Last year (first time winterizing it myself) I flushed antifreeze through the whole system and then unhooked everything. In my opinion, leaving everything unhooked is a better choice just in case there happens to be some water that is able to freeze....not trapped in an enclosed space if everything disconnected.

10-18-2011, 01:26 PM
OK...so I read the recommended process...but...which one of those disconnections/draining procedures (ie...which hose(s)) is the one that is really draining the block? My question is simply coming from this angle: I've always run coolant through my system and never had a problem...however, now that I'm giving it a second thought...if the motor isn't running hot enough to open the thermostat, then the coolant I'm running through isn't really replacing the water in the block, right? Just looking to become more educated and understand which areas of draining are the most critical. Anyone? I too have the LY6 motor if it matters.

10-18-2011, 02:21 PM
In our 2007 LY6 we do not disconnect anything and run the engine up to temperature then remove the hose from the fresh water pick up and run about 4-6 gallongs of RV/Marine antifreeze through it and verify that it comes out BOTH of the rear exhaust openings. This makes sure the antifreeze has made its way through the entire block. Best way to make sure is get a cup and collect the water/antifreeze from the exhaust as it is flushing and make sure it is the same color as the antifreeze (usually pink). We have done this for several years and never had an issue. This boat is in Colorado and stored inside in a non heated space.

10-19-2011, 02:15 AM
I also like to remove the thermostat just to be certain the antifreeze finds its way into the block. It's probably not necessary, just like using the antifreeze isn't necessary, but I sleep better all winter that way...