Overheating problem. Help !

[Bill Smith]

A couple weeks ago I set the boat down off plane into some thick mud. I tried a couple times to throttle out of the mud as the boat was still floating but realized it was blasting mud out the jet. I stopped and pushed it out into deeper water and fired it back up. Let the raw water run through it a bit and it began to overheat. Clean water coming out of the jet and the pilot hole. Took it home and flushed it with no overheating. Went back out this weekend and it's overheating again. Tried flushing it 3 more times still overheats. No obstructions in the intake, exhaust, pilot hole, and the flush water is coming out of the intake grate clean. Any ideas ?

 

[Julian]

I wonder if the thermostat has something clogging it?

 

[Bruce]

How do you know she was over heating? Was it the dash indicator? Did you see steam coming out of the pee holes? Did the engine go into limp mode?

Did you check the small intake filter on the side of the pump where the cooling water is captured?

Is anything in the jet pump causing cavitation? I have had two experiences with over heating. Both were due to things stuck in the jet pump causing cavitation.

 

[Bill Smith]

Removed the thermostat and it looks to be ok. Small amount of grit on the spring but nothing that looks like it would impede operation.

The check engine light came on and boat went into limp mode. The water stream from the pilot hole and the jet are essentially cool. The water from what I believe is the exhaust dump is hot as hell from startup cold so I assume that's normal.

The small white filter runs with clean water on flush. No dings in the impeller or anything that looks like it would cause cavitation. Also remember is overheats on flush which takes the intake grate and cavitation out of the mix.

I truly don't know if it's actually overheating. I checked the cylinder head temps with an infrared gun and got in the high 190s to 208 but that's the metal temp and not the cooling system temp. Not sure what they should look like. I know the overheat warning comes on around 180 on water temp but I have no easy way to measure that.

 

[Bruce]

Have you checked to see if the temperature sensor is clean?

When cavitation compromised water flow to my engines steam started coming out of the pee holes. The jets had sucked up a lot of trash as we were approaching a ramp in a cove at night. I got out to back the trailer down the ramp and Rana (wife) discovered steam while she was waiting to load the boat.

 

[Ilmmct]

Bill my mechanical skills are light. But earlier this year I had an engine overheat situation in my 242 LS, that was caused by a thermostat that had corroded. At some point during the overheat event(s) an exhaust line reasonator melted. This is a black plastic component of the exhaust and the melting restricted the exhaust flow which caused heat to build-up.

 

[swatski]

I agree with @Bruce -- sounds like a bad temperature sensor.

--

 

[ToddW850]

I'm drawing a blank on the actual name, but what about the screen in the jet pump that feeds the cooling line? It could potentially be clogged from the mud and not allowing proper water flow into the cooling system. And the reason it does not overheat on the hose, is because the hose water comes in from a different location.

ADDED: I believe it's called the Cooling Inlet Filter....Looks like a square screen

ADDED: Nevermind, I see @Bruce already mentioned it. Somehow I didn't see it on the first pass.

 

[Julian]

Do you have access to YDS to read which sensor is throwing the error? Add your location to your profile and someone near you might be able to assist if they have YDS.

 

[Bill Smith]

Doesn't the YDS only go up to like 2013 ? I thought the newer boats needed something different.

 

[FSH 210 Sport]

Doesn't the YDS only go up to like 2013 ? I thought the newer boats needed something different.

I wonder if @BillSmith ever got this problem taken care of …. Inquiring minds want to know…