Water pressure gauge and warning beep

[Jgarrison52]

2B690679
Mercury 4S Pro XS 250
Four Stroke
250
4.6 Liters
8
1.75:1
98 hours on motor. 100 hour service done.

The boat has been sitting for over a month. Stored Indoors
it was cold this morning when I launched (30 degrees, Cole by NC standards). I let the boat warm up for 5-6 minutes before I took off which was a short run.
after about 4-5 stops and running no further than a mile the boat started and I proceeded to get on plane and it gave one loud beep and then it went into protectective mode and would only allow me to idle. I turned the boat off and connected my phone to the vessel view and start checking for faults. No faults found when I restarted the boat. That’s when I noticed I was not getting a reading on my water gauge. 0 psi.
I proceeded to idle and it beeped one more time (one beep) and no fault registered on vessel view. Water was flowing out of the motor fine.
everything checked out after I restarted and idled around… no more beeps, it was peeing water just fine. I proceeded to idle around for some time and everything seemed okay. Minus the water gauge registering anything.
temp was good and still peeing. I proceeded to get on plane and drive around a couple of times with no issues.

-the rest of the day I didn’t receive any more beeps of the engine governing me down.
-good water flow peeing outside the motor
-I thought there seemed to be more white smoke than I ever remember but it was cold here. I rarely fish when it’s this cold.. (This was very minor) did not smell like burning.
- oil was checked and it was full.

not sure where to go from here….
I was nosing around with the cowling off and did notice a black piece of a tube that had a red piece of plastics coming out of it. It was just laying in the bottom of the motor. I took a picture and will attach. My fat fingers could not reach it.
any help would be greatly helpful.

-

[EuropeanAM]

Need to get it on the G3 Diagnostic System for a full report. Something serious was occurring- that warning indicates to shut the engine down as soon as safely possible and get it to the dealer for service before further use.

[Jgarrison52]

I did find out that the motor will start to overheat only while idling. As soon as the engine revs up to over 2000 rpm’s the temperature drops down to the 120’s. While idling it will start to climb near 140.
any thoughts?

[Robby Moser]

140 isn't overheating,my 200 Pro XS 4s runs 136-140 in early spring,and 138-145 in summer VVM. Like Don said,need to get the report to see what it shows.

[Pulsare2020]

140 isn't overheating,my 200 Pro XS 4s runs 136-140 in early spring,and 138-145 in summer VVM. Like Don said,need to get the report to see what it shows.

^ My 300R runs similar temperatures to the above post (slightly lower) in the early spring and summer. Always has, both before and after water pump impeller service.