2020 RXT 300 Beep and Limp Mode. No codes stored

[acesfull145]

I just bought a 2020 RXT-X 300 with 69 hours on it. I took it out for the first time this past weekend and everything seemed great for the first 20-25 minutes. While going about 30 mph, I heard a loud 2 second beep and it went into limp mode with the CEL on. I wasn't aware that I could pull the code at that time. I killed the engine, hung out for a few minutes and restarted. No CEL. Drove around for another 10 minutes and it happened again. Killed the engine, hung out and restarted. No CEL. Made my way back to the dock after that.
I did notice that the oil seems to be overfilled so I'm getting an extraction pump today to get that right. I'm wondering if there's anything else I should check? It's a couple hour process roundtrip to get it in the water to check it out. I also don't want to damage anything.
It was a private party sale so no idea how long the gas has been in it. Oil looks brand new

 

[ski-d00]

Overfilled oil doesn't usually throw any codes, it just runs slower with a little smoke. You need to pull the code while it's happening on your screen.

 

[acesfull145]

So the code is P0298. My mechanic thinks it's a bad connection from corrosion on the wiring harnesses. He sprayed some dielectric grease on it but didn't help. He's suggesting replacing the harnesses and the oil temp sensor. I haven't seen anyone else with a P0298 say that this was a fix. The couple that I was able to find said that it was the oil cooler - once they replaced it stopped happening. My mechanic said that if the oil cooler was bad, there would be water in the oil, which there's not. Is that always the case?

 

[ski-d00]

More likely you have a blockage in your cooling system or could be a thermostat problem causing the blockage. There are 2 thermostats in your cooling system. Even replacing the oil cooler is usually from it clogging up. You have to check your entire cooling system including the pump, hoses, and ride plate for proper free flow.

 

[mkov608]

P0298 ... engine oil overtemp right?

1st step in the manual. "Check for debris/blockage in the lubrication system." Do you know if the engine has been out for repair? Calas performance has a lot of videos on You Tube where he pulls apart engines that the "assembler" killed it with too much RTV on the sealing surfaces; that extra RTV breaks off and clogs the oil pump and scavenge pump screens (oil strainers).

2d step: test the resistance value of the oil temp sensor. If your out of range change the sensor. If in range, go to 3.



Step 3. Reconnect the OTS sensor connector and test the resistance of the OTS circuit to the ECU. If out of range, fix your wiring; if in range, check the ECU.