Kohler 7.3 Cooling issue

[bud37]

Source of the post Thanks Bud37! So would you keep it that way? reinstall the top only? if I do that, I refill the fluid I lost, and start looking for another reason it wont stay on.

Me...I probably would and check temps everywhere......but I had an edit above, kind of happened at the same time...there is no reason not to put a good thermo back as Tom suggested.

[650Guy]

thank you! I'm ordering a Thermo kit now and begin searching. I know this is going to sound ignorant, but how do I check temps in different locations? this I'm a bit foggy on.

[tomschauer]

Several hours with an ohm meter on the run circuit. a lot of swearing and many beers!

[650Guy]

hahaha, well when you say it like that, it sounds so fun!!! sounds like I have my work cut out for me though. that being said, you have really saved me thinking that I had parts floating around in my cooling system. so that is a HUGE win!!

[bud37]

Source of the post thank you! I'm ordering a Thermo kit now and begin searching. I know this is going to sound ignorant, but how do I check temps in different locations? this I'm a bit foggy on.

Get yourself an Infra red temp gun...these little things are indispensable for troubleshooting on a boat for checking temps on exhaust hoses ,fittings, blocks,heads, wiring,,...the lake, you name it.......google IR temp gun..get em anywhere now......good luck man.

[mjk1040]

That thermostat was takin apart. Since this is a closed cooling system you have to bleed off the air when refilling the antifreeze. An air pocket in the cooling system will give you over heating and thus shut down. There should be a bleeder fitting near the thermostat housing. It will look like a brake caliber bleeding screw. Also make sure oil level is correct. Low oil will shut the unit down too. Another approach is to add antifreeze until its just over the internal core at the radiator cap. Start gen with radiator cap off and watch it, It should start warming and flowing, and if fluid level drops add some more. I'm thinking previous owner had this air lock issue and thus took the thermostat apart trying to get the air out the system, however as I stated before if the antifreeze flows too fast without the thermostat it will not cool down.

[650Guy]

Oh man!! You guys have just saved my bacon!!! I won't be back to the boat til next week, but I am positive you are onto something!! I bet I have an air bubble or something in there. Most of the coolant got drained out as I have been chasing down missing parts, that were not ACTUALLY missing... they were just never there! ha! So maybe by me refiling, starting and bleeding may... just MAY... solve my issue!!! that would just tickle me pink!!!!

As usual, 1 evening worth of typing on this forum saved me days of cussing, stress, and financial drain!!!

[bud37]

Source of the post You all are making me feel much better! Parts floating around my Gen's cooling system does not seem like a good thing to me.

Bud 37 -
"Have you used the Gen since you owned the boat" - That answer would be no, During the survey, we ran it and it took a load just fine, then we shut it down. In hind sight, it never ran for more than 5 mins and she seems to run for about 10 or so before it shuts down.

Do the edges look like they corroded away or cut ? - I have included pictures (hopefully)

MKJ1040 - what is a "RydLyme treatment"? I have never done one of those?

If you are going to put a new thermostat in there, you can help getting any air lock out by drilling a .125" hole in the ring flat , right between your thumb and the centre in the one pic. Seems to me good marine ones came like that years ago....memory is a little fuzzy, but that will work if that is the problem, hopefully.

There is an accepted procedure for making sure to get the air out. lets just see how this goes as there are many reasons for the shutdown symptom other than actual overtemp. There is stuff in that black box that sits at the top back , right where water leaks past the deck seals if its the same as mine.

[650Guy]

Man your right about the water dripping right on the black box. Every time I open that hatch it drops right there and can’t help but think that’s probably not ideal!

My fingers are still crossed for the bleeding of system plus new thermostat solves the issue.

Thought just came to mind though, has anyone ever heard of the coolant pump going?

[Viper]

Short of an actual engine, ignition, fuel or electrical issue, there's typically only a few sensor faults that will shut them down; low raw water pressure, low oil pressure, engine temp, exhaust temp, and depending on the unit, certain failures in the actual generator portion itself.