1.8 NA Over Heat Gremlin

[14SX190]

I am open to suggestions on what to do next to find reason for "OH" alarm which kills power. At first it would go off once then fine rest of day. Happened again and again same thing a few outings. This past outing four times I had to stop. I checked obvious things every time during wash down at home. No alarm on hose.
I did not have heat gun with me for temperature check but EM did not sizzle spit (Old days of Nitro RC) but pee tale was on warm to hot but not scalding.

This started after new oil cooler was installed. Otherwise it is flawless in performance. Boat runs fine at 47mph despite new metallic noise I hear outside of the water like impeller hitting housing. Going to also remove pump next. I was trying to avoid it as there is no loss of thrust but now I have that noise.

Things I have done:
1. All cooling lines blown through with no restrictions
2. Jet pump screen clear
3. I have tested thermostat with boiling water and it pops open. Going to run with out and see if it stops.
4. Removed Thermo Sensor under cylinder #1 Intake Manifold. Still has dielectric grease inside rubber boot. Sensor appears intact. I am willing to send Thermo Sensor to someone who can use Multimeter and interpret service manual procedure to test it.
5. Removed hose from EM nipple and had significant water flow while on hose.

I am hoping to reach a member that has knowledge to test it or member who has sensor and willing to ship it to me to diagnose a bad one before ponying up money on a sensor and not be problem.

Already tried FS section to guy from a year ago and no luck....

Weather is not good in Miami so I don't mind problem solving if I can.

 

[WREKS]

Most, if not all, of the overheats I have experienced were due to slime buildup from residual water left in the cooling system after flushing. Water fed micro-organisms easily build up in the cylinder water jackets and cannot be flushed out through the tiny holes in the head gasket. Prevention is the cure. I periodically run the engines without cooling water to heat up and dry out the cooling systems. No water, no slime, no overheat.

 

[Cobra Jet Steering LLC]

heat sensor failure I had the same problem on a 2014 1800 engine

 

[14SX190]

heat sensor failure I had the same problem on a 2014 1800 engine

I saw your name mentioned as I searched but confused as to which one? I just saw there are "two". A sensor and switch. Sensor is #13 and Switch is #15.
I was looking only at #15. Need to inspect #13 now. Also, What is the one connected to muffler #3 "sensor"

Most, if not all, of the overheats I have experienced were due to slime buildup from residual water left in the cooling system after flushing. Water fed micro-organisms easily build up in the cylinder water jackets and cannot be flushed out through the tiny holes in the head gasket. Prevention is the cure. I periodically run the engines without cooling water to heat up and dry out the cooling systems. No water, no slime, no overheat.

I do the same after flushing a few times.

 

[Cobra Jet Steering LLC]

I had it covered under warranty What happened was one of my sons decided to take a rid on one of my skies without my knowledge,, he went through a bunch of weeds and it went into limp mode according to him he finally decided to get the weeds out of the pump, I suspect he drove it a while in limp mode and why I preach that limp mode is NOT safe MODE> and it ran fine but ever since that incident the alarm would go off and it would go into limp mode with no obvious reason.
like yours it was intermediate but it soon became a constant issue with no apparent reason no hot readings any where and finally I took it to the dealer who found the sensor and fixed it under warranty so I never actually knew what one it was and didn't care since it was rectified.

 

[14SX190]

Think I found problem and correct sensor.

 

[Tommy Bierly]

Where was that? Which sensor?

I have a gremlin too

 

[14SX190]

Where was that? Which sensor?

I have a gremlin too

Number 13.
Back under cylinder #4 Intake

 

[David Martin]

Thats ugly.....at lease you found it.....Talk about corrosion Yakes!!!!!!!!!!!

 

[14SX190]

Thats ugly.....at lease you found it.....Talk about corrosion Yakes!!!!!!!!!!!

Ill post other picture of it taken apart. It wasn't corrosion
Its a rubber boot encasing a thermostat bulb end on a copper wire. It sits inside of threaded portion that goes into block.

Not sure if that will be cause of OH alarm but have new one on order since I ruined rubber casing.

 

[14SX190]

Sensor apart

 

[Tommy Bierly]

How did you get that out? I found it... but it's just in an awkward position. I need Gumby arms and a very narrow wrench.

 

[Tommy Bierly]

...thinking about just disconnecting it for now...

 

[14SX190]

...thinking about just disconnecting it for now...

I removed the intake manifold but it's accessable just not convient

 

[Tommy Bierly]

I got it off and replaced it. Made a few trips with no overheating alarm, then it happened again.
I replaced the thermos stat (it looked terrible with rust and corrosion) and so far so good. Someone else mentioned a sensor on the water block. Anyone know what sensor that is???