Question on my Winterization methods.... 502MPI
 

So, to make a long story short, i'm trying to figure out if my head gasket leaking is self induced...... Due to my winterization methods? Not sure. Just looking for verfication of what i've done for the last couple of years.

1. Run engine on hose and get water temp up to 160, oil get's to roughly 140ish.

2. Pull the oil out and fill with fresh including filter.

3. Drain the block and exhaust manifolds of water. I have not been pulling any hoses off for the cooler, the boat has always been in heated storage up to this year so I was less worried about diluted antifreeze. Reinstall all plugs.

4. Mix up a 2 gallon gas can of stabilizer, a little bit of 2-stroke oil, and ethonol free gas to run the engine off of.

5. Fill my West Marine tank with 5-6 gallons of the pink rv antifreeze. Don't know the teperature of the antifreeze...

6. Start motor and suck in the antifreeze while running off the gas mix. When I see antifreeze running out of exhaust i shut off.

Now I've been told that I could possibly warp heads/deck due to hot motor getting run without water and then getting the cold antifreeze siphoned in. It takes about a minute or two for the 6 gallons to get pulled in. I usually winterize on a 50 degree day or so, and I'd say the engine is warm, but not up to operating temp by time I had run the first time and then the second time empty.

Any thoughts on this procedure? It was suggested to change the oil one day, and then put the cold antifreeze in the cold empty block the next.......

Makes no difference. Not the cause of head gasket trouble.

X2 didn't cause your issue.

I have been basically doing my boats that way for almost 20 years with no problems using automotive anti-freeze or the non toxic marine stuff for engines Blue/green color. Your engine gets up to temperature in early spring and fall and sucks in cold lake water too.