David, thank you for taking the time to do this video. Excellent and straight forward explanation. Your video could potentially save me a lot of money. Thanks again, Ron
Just an update. My repair is still holding. The manufacturer said when it works it's almost always permanent, but if the crack is too wide the leak stop may not be able to seal the crack. One more thing. You need to first determine if the crack is into one of the combustion cylinders. Mine was not, but if yours is, all you need to do is remove that spark plug while running the engine with the leak stop in the cooling system. The manufacturer says it can seal a cracked cylinder but to allow it to seep into the crack you can't have the cylinder pressurized.
i gave the boat to a new owner w/ the knowledge and ability to take the risk of dealing w/ the engine core plugs. i was heading to install a new engine or at least pull the engine to get new core plugs in the right way.. good luck.......
@@perryshields8820I'm about to do the same to my 4.3 block in a cuddy cruiser that I just got for a song. I'm going to test compression on each cylinder, and I don't think a cracked cylinder will show much compression on the guage. Plus, cylinder cracks are more rare than other ones
I had a cracked 3.0 Merc. Crack appeared to be internal as I had no exterior leakage and oil was getting milky. Last weekend I constructed a tank of about 8 gallons to allow my cooling water to recirc and used a whole bottle of K&N block sealer, ran for about 15-20 minutes and it appeared to have sealed the crack. Boat hadn't run in 12 years to the accuracy of my temp gage was questionable, but it never got over 185 F or so. I could put my hand in the tank quickly without burning myself so I would guess the temp was less than boiling or 212 F. I ran the engine again this week for about 15 min on the muffs and oil looked good after. Super pleased obviously.
Wondering why this guy didn't just do that, you could just stick prop in bucket out of gear that is full enough to submerge where muffs go and gather with another bucket from pee hole and dump it in first bucket and sit there recycling it.
Awesome video, thanks. I wanted to add that if your dipstick tube runs off the drain plug, it’s possible it’s deceiving you. My oil looked perfect the only way I knew it had water in it was because the oil level went up. Of course I didn’t know I had a problem until I washed out my bearings and spun a few of them.
I had a 5.7 Chevy engine with a bad intake manifold gasket that had the same issue at 65,000 miles. Dealer said they wouldn't know until they tore it down. A friend told me that these were famous for the intake gaskets failing and causing this. I put 150,000 miles on that truck after that with no more issues.
Good to hear it's still working fine, exceptional in fact. These blocks will crack if not winterized b/c the water trapped in the cooling jackets will freeze during cold weather, expand and crack the cast iron.
I have this exact problem on the same exact boat..lol you may have just saved me 5k for new long block. will attempt this over next few weekend.. intimidating for me but you laid out video very well
GREAT presentation!! I will certainly save this video. . One thing I don't understand. Where is the water going that you have plumbed into the system coming up from the lower unit impeller. Seems like it would be over pressurizing the system. . I will continue watching for your reply. . . Jake
David, why were you concerned about running the treated water through the exhaust risers? I was going to try and do this without the radiator and just collect the treated water using 2 hoses plugged into the transom raw water outlets into a tub with the lower outdrive submerged. TIA
Thanks for writing. Ultimately I know it doesn’t always work. I’m hoping for a summer and then re power. I’m not getting a lot of water in my oil. Very little actually, but that’s not under strain. Still I think it’s worth a shot. Line up for 4.3 Mercs here.
What grinds my gears is they should have built the cooling systems to automatically drain most of the water out completely overnight after shutting it off.
Nice video. Tank you.. just on my thermostat I have 3 lines (Mercruiser Alpha 4.3 2003) 2 lines from manifolds, large pipe from the pump. Where can I find output water line which. Will be connected to the top of Radiator ? Will appreciate your answer
In my opinion this is poke and hope. I use a process made for this. It's a series of threaded plugs that interlock permanently sealing the crack. Its a much better repair. Made by a company called lock-n-stitch.
Lock and stitch works great, IF you already have the engine out and stripped down. This is for guys that just want a quick fix (hopefully fix) while the engine is still in the boat.
@@strikeforcek9149 I pulled mine out. But I could have easily done it in the boat as well. I've only got the 3.0 merc. A v engine would have been a different story.
@@donmunro144 I'm debating doing the same right now. I have a 5.0/305 that is literally brand new with only around 15hrs on it, and it cracked over winter (bad winterization). So debating on using lock n stitch, or just replacing the short block. Such a pain in the ass, all from someone taking shortcuts lol. But, I got into the boat for the right price, so I can't really conplain I guess.
I think with lock-n-stitch you also have to be able to find the crack and have serious access to its location. I have an crack that is accessible and I’m looking at lock-n-stitch and belzona solutions, but have to consider that there may be other cracks I can’t see and this solution could prove quite useful for that.
It usually works very well,provided you *fixed* very well the original overheating problem; it is nothing special,just sodium silicate,also called liquid glass
Does it have to be used with a radiator or would 15 gallons of water or so covering the outdrive work as well? 3 cans would treat 18 gallons of water, the only thing I can think of is not enough pressure but what is your opinion?
You can do it that way. However that brings the stop-leak into the exhaust manifold heat risers. I wanted to contain the stop leak within the engine. It is also difficult on my boat to collect all of the water coming out because some of it comes through the exhaust and some at the transom
Ya Ok ....cracked block, warped head, water in oil. Lets see...is some sort of crazy crap gong to fix it....nope, your engine deals with heat, compression and for the most part critical tolerances...
Nice presentation and appreciate your methodology. You're a fellow son of Rube Goldberg! How many hours do you estimate you have put on the boat since the repair? Must ask, were you paid for your product plug? 4/11/21
where is the up date? i fear the worst has happened... i got caught by this early freeze and found a core plug in the bilge. i gave up my winterizing day for my wifes borthers son weding i haven't seen in 25yrs...... i am hoping it is just the plug but is there is a internal crackin the block i wo't risk going on the open water of the great lakes. outside crack maybe i would do a repair internal crack no way. re power w/ an outboard/s.
Hi mr Zif001, I have a crack on the outside and iv'e just epoxy metal weld a plate of steal over the crack. not sure if i have a internal leak too, milky oil...
Me too. It's only 7k. But at least I won't do the ole Pistol Shot on the Terrace ARRGH. What size Tee is that? The night hose fits on it and the 2 smaller also fit. But the Tee looks like it the same size on all 3 sides. Geesh .. confused
Im marine tech i fix blocks and wat u did is not right i bet under load ur motor wit water it will turn milky the right fix is open it up and see wat broke and fix