Engine overheating / check engine light - 2007 Outback V w 325 Indmar Assault

[Team Smith Outback V]

My temp gauge on my 2007 Outback V was going in and out but when it functioned it seemed to indicate that temp was on target in center of the gauge at 160 degrees. I just replaced the sending unit for that gauge through Discount Inboard Marine. Now it seems to go up to just above the 180 degree mark whereas it was firmly centered at around 160 degrees for years. I have changed my impeller but had no missing blades although it was a bit firm and less pliable than the new one. I have pulled off hoses and not seen anything impeding water flow. At this point the only thing left I believe is to replace the thermostat.

I have not driven it for more than about 5 minutes so can't confirm that it will stay at the 180 degree mark or continue to increase. It did seem to stabilize there (neither increasing or decreasing) but I was nervous to go out and have it get worse. The gauge tops out at 240 and there is not much space between the 180 mark and the 240 mark so I start freaking out when it gets up there since there is no real visibility beyond that. I have noticed that the check engine light is also on now. Engine seems to run like normal and I do have power but just makes me really nervous....

Couple of questions....

Is the thermostat really the only other logical place to look or any other ideas? I did have an issue earlier this season where the hose between the circulating pump and thermostat blew out and I took on a bunch of water into the bilge. I never saw any engine issues with that and don't believe the engine overheated as it still turns on fine and no more water is leaking now that hoses have been replaced. Would lack of water to the thermostat cause it to fail? I can't imagine that this new issue is connected to that incident but that was the last time I used the boat for more than 10 minutes of riding...

It sounds like the sending unit is working OK but that should not need to be calibrated or anything should it? My impression from Skidim was that I just screwed it in, connected the wire and that was it.

Any thoughts/guidance would be very much appreciated!!! Season is winding down and I am still hoping to get this corrected and get a few more days on the water before closing things up for the winter.

[htfit]

I know on my 2003 Moomba the termostat stayed at 180 degrees. Then it became intermittent and I replaced the gauge. It still said 180 degrees after it warmed up.

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[MJHSupra]

Not really that many components to check. Some are very inexpensive to replace - like impellers, hoses, and thermostats.

* If you have a strainer installed, there might be blockage.
* Making sure your hoses are properly attached and not getting air in lines
* Water Pump Impeller.
* Belt spinning the Pump
* Leaks in the Pump Housing
* Debris in the hoses running past the Impeller
* Thermostat

[Team Smith Outback V]

Thats kind of what I have been assuming. Cooling system seems pretty straightforward. Thinking I will replace the thermostat at this point. As you mentioned, its not an overly expensive part and in looking at it it seems pretty straightforward. Just pull a couple of hoses off, 2 bolts, replace gasket and drop in new thermostat. This stuff does intimidate me a bit though. Let me know if you feel the thermostat is any more complicated than that.

Would this level of overheating cause the check engine light to come on in your opinion? Are boats like cars where you can plug in a scanner and get an error code to learn what the issue is?

[MJHSupra]

It may sound stupid, but make sure to not mount the thermostat upside down. Not sure where I've seen the pic, but someone (probably a dealer or repair shop) posted a pic of someone mounting it the wrong way and they were fixing it. There are a few places to buy that part online - Bakes, SkiDim, etc.

Overheating will throw a code and I think those model years causes the boat to go to limp mode.

Scanners - yes, dealers will have the correct software/tools to plug in. Not like my truck scanner where you buy them on Amazon.

Per error codes, when I threw a low volt code on my 2007, the system will auto clear the code after ?3? successful startup and shut down cycles. Not sure of the exact number of those cycles right now (3 is my guess), but there is a thread on here about it where someone from Indmar posted that info - Larry the Engine Nut. Worked for Indmar. Great dude.

[VA LSV]

Check for debris at the transmission cooler. It's the 1st raw water connection at the motor after the V-drive. Hard to see so I use my finger to clean it out.

[Hayden]

Check for debris at the transmission cooler. It's the 1st raw water connection at the motor after the V-drive. Hard to see so I use my finger to clean it out.

This. If you don't have a strainer this is the first thing I would check.