5.0L High Temp Alarm

[FamilyTime]

I've had a couple issues with my port engine. I had a two beep per minute that was fixed by an IAC replacement. After we fixed that we went out on a cruise and about 45 minutes into it the high temp alarm went off. We were cruising at 3500 RPM and 25kts and the temp slowly crept up from 170 to about 195 or so. All other indications looked good. The impellar was replaced a few weeks ago. Should I pull the thermostat? How is that done? Is there a way to check the raw water lines for obstructions? Thanks for your help.

 

[BillyT0020]

I would probably start by replacing the thermostat since it would be the cheapest and easiest fix. There are two bolts holing the top of the thermostat housing on, towards the front of your engine (in boat), with 4 hoses coming off. Take the bolts off, lift the old thermostat out, scrap off old gaskets and replace. Its a really easy job but make sure you get all of your old gaskets off or you'll get a leak. I like to lightly sand to bare metal with like a 220 grit sand paper to make sure.

If that dosn't fix your problem then replace your raw water hoses with clear hoses so you can see the water path and check for obstructions.

Good Luck