Damage from Overheat (??? water in oil)

[rybad]

OK.. I did a dumb thing.. forgot to change water intake impeller. 89 OMC 5.7/350.<br /><br />I overheated at launch this year, the engine shut down by the time I noticed. After it cooled, I started it up, and it appeard to run fine (sounded normal). Due to the overheat, I toasted the upper exhaust hoses off the riser, so I replaced them, the thermostat (and the exhaust seals) -oh, and the impeller (which was shot). <br /><br />Anyway, immediately after replacing everything, I started the motor engine, ran it for about 15 minutes, watched her get warm (170-180), cool a bit, and basically stabilize at that temp. Everything sounded normal, ran great - no problems.<br /><br />I went to launch the following day, and the engine would not turn over. It seemed like a weak battery. I would get "half cranks" and could hear the starter hissing (like it was getting power but jammed). I nursed the boat back to my marina on one engine. A couple hours later, I tried to start it again, it was very difficult to start but eventually it did. Now, it appeard to run "rough" like bad gas, or carbon build up. I ran it to op.temp and spayed OMC Engine Tuner in it until it stalled out. I tried to start again immediately, but again, got weak or jammed crank.<br /><br />The following day, after checking the batteries, cleaning terminals and all of the obvious "easy" stuff, I was going to remove the starter (which is not easy) and have it checked. While working around I removed the PCV valve tube and notice some condensation. I checked the valve covers, and they have milkey dropplets in them. I checked the oil in the pan (w/dipstick) and it appears to be fine .. no presence of water, although I am going to drain it tonight, as the water could sit above the bottom of the stick level.<br /><br />My question is.. If I blew a head gasket, or cracked/warped a head, would that in any way cause the engine not to crank over?<br /><br />At this point, I dont know where to start.. rip the heads off, or take the starter out. I'm not sure if the "water" in the oil is actaully water, or if that may be from the OMC Engine Tuner (which is a white liquid in an aerosol).<br /><br />Also, if the head was warped and causing the problem, wouldnt that be presend right after the overheat (the engine ran great on two occasions after the overheat - with no problems).<br /><br />Also worth noting, the last time I attempted to start it, there was a steady "knocking" sound, in 4 swift, percise intervals as the engine cranked. I cant duplicate that again, as now I only get the "half cranks" again.<br /><br />Any suggestions are greatly appreciated!!

 

[Northern Eclipse]

Re: Damage from Overheat (??? water in oil)

Pull the spark plugs and crank the motor you may have cracked an exhaust manifold and are getting water in the cylinders, which will hydrolock the motor and cause it to be difficult to crank.

 

[rybad]

Re: Damage from Overheat (??? water in oil)

Thanks..<br /><br />What will I be looking for once I pull the plugs?? If it cranks, do you think water will be visable there?<br /><br />When you say "hydrolock" (that sounds bad!) I'm I looking at replacing the motor altogether ??<br /><br />Thanks again.

 

[Northern Eclipse]

Re: Damage from Overheat (??? water in oil)

With plugs out and crankin,If water is present you will see it being blown out the plug hole, Hydrolock is when a liquid such as water has invaded the cylinder, either from it being sucked into the exhaust or water getting down the carb, and filling the cylinder, Hydrolock will then occur when attempting to turn motor water will not compress, and will lock the motor, yes in the most severe cases it can bend connecting rods, but if you detect water in cylinder(s) there is still a good chance motor can be saved if you first find the source of water and correct it, change oil and filter. When you pull the plugs and if any of them look super clean then that could be a sign of water, water getting into a cylinder, can shine a plug like new, sometimes they will also look clean with white mineral deposits, also check oil is it foamy or look like a milkshake. At the very least I would also do a compression test followed by a leakdown test, but getting hot enough to melt the exhaust boots also means the exhaust manifolds ran dry, which means you more than likly toasted the exhaust shutters that would normally be found in the top of the ypipe, If they melted off the remains could be stuck down the pipe causing a exhaust restriction thus a poorly running motor. So just a recap Check for water, pull exhaust boots off and see if shutter is still there ( looks like a rubber butterfly). have compression test done, could help you determine if head is leaking. <br /> I re-read the end of your post and noticed you state that the motor was clanking when cranking, That may not be very good news, Compression test is a must, that won't fix but will tell if its broke, you might find its broke. I hope you get lucky and its not broke. let us know what you find.

 

[rybad]

Re: Damage from Overheat (??? water in oil)

As per you suggestion (removing the plugs), yesterday, I went down to the marina to do that. As I put my hand on the exhaust man. to lean down to the plugs, I noticed water. I got a rag, and squeezed into the bildge. Once there, I noticed two places on the man. that look cracked, and (sure to my luck) another crack on the block about two inch's under the cylinder head. I wiped them off, and watched to see water ever-so-slowly uzing out - so I'm screwed.<br /><br />Just for kicks.. I pulled the plugs - water poured out like I was filling a glass from a pitcher!<br /><br />Another question.. As the boat rocked in my slip, water would "spit" out of the plug hole, as if it was coming in from the exhaust man (??) .. does that make sense? I did already replace the exhause seals (you referred to as rubber butterfly, above)<br /><br />Thanks.. I've already contacted BoatUS to make a claim.. they will be calling me back in 72 hours.. wish me luck.<br /><br />Thanks again.

 

[highaltitude]

Re: Damage from Overheat (??? water in oil)

this sounds like feeze damage instead of overheat damage. chances are there are internal cracks inside the engine block.

 

[Northern Eclipse]

Re: Damage from Overheat (??? water in oil)

Sorry to read the bad news, and yes it does sound like she froze up, which caused the overheat, Hopefully the insurance covers freeze damage, I know mine does, but only if I winterize by paying a authorized mechanic....looks like a complete crate engine is your best option since you need just about everything, let us know how you make out with your insurance.