2018 180sx overheating.

[Chucksx190]

Hope someone can shed some light on this issue for me. I have a 2018 sx180 with 87 hours on it. It is used in salt water but has a 15 mile ride home in a fresh water river and is flushed with salt away every outing as soon as we get it home. It is stored on a lift out of water. I took it out today got it about 12 miles out, for the last 2 miles I was wide open 7700 rpm 44mph most of the 2 miles. I slowed down for a 5mph zone and about 5 seconds later the check engine light came on and over temp was flashing. I looked at the pisser and it looked fine so I shut off the engine. I always carry my snorkel, goggles and a dive flashlight. So I jumped in the water and checked the grate. It was all clear. Next I looked in the jet nothing in there and the water feed screen was clear also. So got back in the boat about 15 minutes had passed so I started it up. Pisser looked normal so I started off again. About a minuet later the engine light went off and over heat flashed. opened the engine compartment and the manifold was warm to the touch and the pisser was working. So I quickly shut it off. A minuet later I restarted it and steam and water came out of the pisser (not boiling normal flow with steam also) its 75 degrees here so its not just water vapor. I turned it off again waited 10 minuets. Started it up reved it up in reverse then forward did this 3 times then turned around and headed home. No more alarm and I went all speeds from 5mph to just over 40mph. Got it home and pulled all water hoses off one by one started the engine and all hoses had good water flow. All hoses and where they attach were clean as new with no corrosion. Has anyone seen this? I have the 5 year warranty but its a pain to get the trailer and take the boat out of the water. Also the only dealer around I trust is 2.5 hours away. Let me know your thoughts on this issue. Thanks

 

[d_coyne1984]

My guess is that after running wide open for that distance the engine had built up a good deal of heat that was being dissipated adequately while there was a high volume of water flowing through the engine, but as soon as you cut to near idle there was not enough cooling water flowing to keep dissipating that much built up heat. I never had that happen to me on my boat, but I don't think I ever ran it wide open for more than a few minutes at a time. I wish I had that kind of space to run like that sometimes. Sounds fun!

 

[Chucksx190]

My guess is that after running wide open for that distance the engine had built up a good deal of heat that was being dissipated adequately while there was a high volume of water flowing through the engine, but as soon as you cut to near idle there was not enough cooling water flowing to keep dissipating that much built up heat. I never had that happen to me on my boat, but I don't think I ever ran it wide open for more than a few minutes at a time. I wish I had that kind of space to run like that sometimes. Sounds fun!

It is possible but in the summer when the temps are mid 90's I have run wide open for 20 minutes or more then slow down for the last 5 minutes to find a parking spot at the sand bar and it has never over heated. My trips to the sand bar I like are around 100 miles round trip. They always consist of full speed runs as its a lot of fun but I have never had it overheat. I should also say I have a 18 FXHO same engine and it sees much more wide open and no issue there either.

 

[swatski]

Cooling should be great at WOT, sounds like it could be a sensor going bad? Temp sensors/thermostats may need to be replaced.

—

 

[Chucksx190]

Cooling should be great at WOT, sounds like it could be a sensor going bad? Temp sensors/thermostats may need to be replaced.

—

I was kind of leaning that way. Is there a consumer diag computer that anyone knows of? One that shows engine data? I work on cars for a living and this system looks much simpler then a car.

 

[Cobra Jet Steering LLC]

Did you check your oil level just to be safe we were discussing this today on another thread where I had an oil filter fail but my overheat light kept coming on and I went through the same thing checking the intake grate etc so just to be safe check your oil and look around the hull for oil sprayed out of the engine if it is low.
Other wise I would also suggest a bad heat sensor.
I used a non contact thermometer and could not locate any hot spots when one of my sensors failed

 

[Chucksx190]

Did you check your oil level just to be safe we were discussing this today on another thread where I had an oil filter fail but my overheat light kept coming on and I went through the same thing checking the intake grate etc so just to be safe check your oil and look around the hull for oil sprayed out of the engine if it is low.
Other wise I would also suggest a bad heat sensor.
I used a non contact thermometer and could not locate any hot spots when one of my sensors failed

The oil was one of the first things I checked. I was looking for water in the oil. Oil level is a little over half way up the hash marks on the dipstick and no water in it.

 

[swatski]

I was kind of leaning that way. Is there a consumer diag computer that anyone knows of? One that shows engine data? I work on cars for a living and this system looks much simpler then a car.

There is YDS but I believe it needs a dealer for reading the newer 1.8 engines, could read older MR1s yourself but not the 1.8. I think.
I can’t look now but there are threads in thermosensor re/placement.

—

 

[Liveto99]

Lack of water flow after running hard
i have run WOT for a hour to get home but if you go right to no wake I think you don’t have the temp difference in the water to get enough cooling.
8000 rpm the motor should do all day long I just look at it as 2 mpg and 7000 rpm is 3 mpg.

 

[Beachbummer]

You probably had some debris in the pump that cleared when you lowered your speed or shut down.The temperature raises when coming off from WOT, but it takes 30 seconds or more to start seeing that rise...I had a recent experience with some weeds that resulted in a overheat, and it only triggered after significant time, and at significant power. 99% it was due to debris. If you don't see it next time you will know for sure. Putting some temp probes in the engine could help prevent in the future. I am measuring now at water and I taped another probe to the oil filter. Very interesting how temps vary with usage, and with debris. I noticed one engine running much hotter than the other and I checked, sure enough, some debris in there... after clean out, back to normal. Not enough to cause the overheat that time, but I saw it.

 

[Chucksx190]

Thank you for the help. I was hoping there was a diag tool that I could plug in and watch the temp sensors. All the plug in tools I find are for 2017 and under Yamaha products.

 

[WREKS]

Chucksx190, Before you go out again, try running it on the hose for ten minutes. While doing that, take some temperature readings of the cylinder block on the exhaust manifold side of the engine. If it gets near 200F, there may be a blockage in the cylinder head water jackets.

 

[Chucksx190]

The boat has not overheated since. I think it was due to going full rpm until I hit the no wake zone with a full load then slowing to 2500 rpm.

 

[swatski]

The boat has not overheated since. I think it was due to going full rpm until I hit the no wake zone with a full load then slowing to 2500 rpm.

I would agree, I have had an overheat alarm go off a couple of times in my 190 when pulling a tube aggressively (in circles). I believe the thing with these boats is to let engines high idle and cool off after hard runs.

--

 

[haknslash]

My guess is that after running wide open for that distance the engine had built up a good deal of heat that was being dissipated adequately while there was a high volume of water flowing through the engine, but as soon as you cut to near idle there was not enough cooling water flowing to keep dissipating that much built up heat. I never had that happen to me on my boat, but I don't think I ever ran it wide open for more than a few minutes at a time. I wish I had that kind of space to run like that sometimes. Sounds fun!

It happened to me once when we had our 192. We had been running WOT for a while on the way back to the dock. We slowed to a stop before getting to the ramp so we could set up the fenders and such. When we started back we got the overheat warning. Ever since that time we made sure never to come to a complete stop of doing WOT runs and always make sure we do more of a high idle / cruise assist level 3 speeds to make sure plenty of water would flow to the engines to cool them and never had the overheat again. Of course this could just be a fluke we had that time and maybe some trash got over the cooling in the jet housing.

 

[Beachbummer]

You should not overheat in that situation, but likely you had a small obstruction in the pump causing some turbulence, and increasing the temp overall.

I have observed this happening with a to gauge. Engine hotter than normal 155 instead of 130-140, check pump, and small stuff in there. Temp returns to normal after crap removed.

Beware.