Indmar 400 Thermostat

My 2021 400 ran hot on me several different times this weekend. Got as high as 230 f briefly. It triggered limp mode on me. It would quickly cool back down, though. It did this several times, and mostly when I was at idle speed. I cleaned the sea strainer, which was not bad at all, and the coolant level is fine. I don't really suspect an impeller issue because it goes up and down. I would think a bad impeller wouldn't cool back down. By the end of the day, it was pretty well maintaining temp at about 160-170 with no issues. I suspect the thermostat and plan on changing it to be safe. Have any of you changed out the thermostat on your raptor 400 or 450? If so, what thermostat did you use if not the official part offered by indmar for $232.00. LOL! They are nuts!

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Go to the local auto store and get a 165* or 150* thermostat for a 2012 Ford raptor 6.2.

Same exact thing.

Or....

https://bakesonline.com/products/ind...ermostat?gQT=2

Yeah. I saw the Bakes you linked to. Also that it's out of stock. I wasn't sure about the length on the ones at Advanced, Autozone , etc...compared to the boat in case there was a particular year model. I didn't know if the housings may differ slightly. Also, is there a gasket or o-ring seal? I have not taken my old one off yet, but wanted to go ahead and have the new one handy when I did to just speed up the repair. Thanks for the advice. And $14 range is what I am used to a thermostat costing! Not the crazy $232 LOL

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I cannot answer specific on the indmar 6.2 but I have worked on a 6.2 raptor f150.

The housing look the same and it should be an o-ring seal. The new thermostat should come with the o-ring. 160* is what you want.

Motorcraft is around $60 for it.

Thanks! I thought it was probably an o-ring style, but again, never having taken the one off the boat, I wasn't sure if there might have been a different design or shape on the neck for some reason. It's one of those things that you don't really look at until you have too.

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Well....thermostat didn't do it. I will change the impeller next. Strange how it will run fine for a while and then run high, then drop again. My experience with impeller is they just run hot. Anyone have any other ideas?

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You could have air in the system.

Is your heater leaking or allowing air in the system?

I do see a slight bit of wetness around the bottom of the heater where it mounts to the floor. Hoses and fittings are clean and dry, so there could be a small leak that is seeping. My coolant level was at the minimum mark. I will add some and see what happens.

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Now I have another issue that just started last night! The fuel, depth, speed, rpm, and autowake all go blank. They will randomly come on and go off. When off, it tells me to see a dealer to have auto wake installed if I select that tab. I jiggled all the wires I could find, hoping something was loose, but no effect. Has anyone else had this happen? Oh, and my temp reading goes to 32 when it happens.

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https://uploads.tapatalk-cdn.com/202...704198ba85.jpghttps://uploads.tapatalk-cdn.com/202...5ba6b38981.jpg

Damn…. Early season bugs to get out of the way it appears….

Not sure if it will help but when my wake plates had a mind of their own I disconnected the batteries for about 30 minutes and it appeared to reset the system

Dont forget to check your hester recirculation pump. Known leak location

Yeah. I totally forgot about the circulation pump. Even though it always showed at the minimum mark, I ended up putting about 2 drinking water bottles in the reservoir, and the temp started acting better. So yep, probably air in the system from a slow leak somewhere. I will also try disconnecting the batteries for about an hour next time I am there. Maybe that will cure my display gremlins. My batteries are 5 years old now but seem to start just fine. However, I'm not sure if they may be part of the problem though. Even though the alternator is putting out 14 volts fine, I know today's electronics are battery dependant. Found that out with my daughter's brand new Kia that would shut off and not crank back for no apparent reason within 1 year. Dealership couldn't find anything wrong. Off of some internet chat room advice, I replaced what tested as a good battery and problem solved.

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Slow leaks are hard to find. It took the dealer a little while to find mine after it overheated once.

You can rent a pressure tester from Advance or Autozone and pressure test the system if you dont have one. They have a big kit that fits most reservoir caps.

The heater circulating pump was the problem for me. I was overheating if I was just ideling but as soon as I got up to speed the temp came back down. I removed the heater pump and saw that it had been leaking. I replaced the pump and decided to refill the system and it solved the problem.

https://www.indmardealersupport.com/news-letter.php

Thanks! Both of these are sending me to check that for sure! I didn't think about the pressure test gage. Think I will start there!

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