2006 4.3l overheated
 

New to boating here. Put my boat in the water on Sunday was out for 20min and my boat died due to over heating. I got a tow back and brought boat back to my house waited until morning boat started up seemed to be running a little rough. I would have to assume since my temp gauge read 240 when it died and once it shut off and was smoking that I have completely ruined my engine. I am going to try and put it in the shop tomorrow however I was trying to find out if there was anything I could check on my own. The boat only had 40hrs on t which is a total bummer. I checked the dipstick to see what the oil looked like it didn’t look like any water was in it. The question is what would normally go bad from that kind of temp? Should I just get ready to replace the entire engine or assume the block isn’t bad? I’ve seen so many people replace these engines but the price varies so much. If I do have to replace any idea the cost of replacing the entire engine? Thanks for any help anyone can shoot my way. I could pull the old engine more than likely myself if I had to taking things apart is easy putting back together not so much. The outdrive is literally almost brand new not even a scratch on it. I am assuming the impeller went out and that’s as the root cause but haven’t tore the outdrive down yet to know. Thanks everyone.

Re: 2006 4.3l overheated
 

I run my Z220 Talari on the Chain O' Lakes in Northern IL. It has very shallow channels and muddy bottom that could cause clogged outdrive intake ports in the lower unit. Mostly, the culprit requires replacing the outdrive rubber impeller due to dried mud & debris. Also check for any obstruction under the upper unit outdrive. I once had a bobber stuck in there pinching the water intake rubber hose going into the transom & engine. It could be simply disconnected. I've never had to replace the thermostat, but that would be my last possibility.

I had a similar overheat issue many years ago when my (now fired!) mechanic forgot to fill the oil during an oil change. Afterwards, the boat ran OK, but it burned oil @ a quart every 4-5 hours depending on how fast I ran.

After one season, I ended up replacing the long block with a Jasper rebuilt for about $5,000. I was told it is cheaper than replacing the rings, possible warped pistons, and/or machining out the burnt cylinder walls. Hopefully this won't happen to you.

Check your oil levels ever time before you go out and afterwards and how much you use. At first, you may want to check the oil level periodically during your day & carry @ least 2 extra Quicksilver quarts in case you are burning oil. I always have 2 extra quarts on-board along with Quicksilver outdrive fluid just in case. I have a 7.4L/Bravo I with outdrive fill bottle in the engine compartment. Hope that helps.