SX192 Overtemp Alarm

[Higgy]

Had my boat out today for the first time since September. I pulled the flame arrestor plug out of the intake when I did the 10hr oil change last fall so I've been patiently waiting for a nice day to see if it made any difference. Well today was the day... a beautiful 70deg day here in the ozarks so I loaded up the boat and launched from Aunt's Creek Park. Hammer down from Aunts Creek Park all the way to Mill Creek Campground. I've never timed it but it's about a 20 minute full throttle run. Just as we reached Mill Creek the RPMs fell to 4000 automatically and I had an annoying beeeeeeeeeeeep and an "Overtemp Alarm" message on the dash display. So I look at the pisser ports. Good strong stream from both ports. Shut the engine off, popped the hatch and took a look... nothing out of the ordinary. No water at the bilge pump, no oil leak, no odd smell... Proper oil level. Pulled the cleanout plug and reached in as far as I could. Found nothing... Decided to start it back up and idle for a few minutes to circulate some cooling water. Alarm stayed on. Shut it down after about 5 mins of idle time and drank a beer. Needed a drink because my new toy is broken... Next time I fired it up the alarm was off. So... dropped the hammer on it again and it was running great. Full throttle all the way back past the the cliff swing (for those familiar with the area) and not long after I took a left at point 10 the RPMs again fell to 4000 and the alarm was back on. Same thing, let it circulate for a few then let it sit and the alarm was back off. This time I took it easy back to the ramp and put it on the trailer.

What do you guys think? Should I pull the impeller and have a look see? I'm tempted to order a sensor... if I could figure out which one it is... The last thing I wanna do is take it to the dealer. They are two hours away and my dealings with them have not been the most pleasant experiences. They don't seem to be in any kind of hurry for any thing.

Thanks in advance for any advice you can offer.

 

[Higgy]

Does anyone know what sensor causes this message? #14? #30? Both numbers are listed as thermosensors. My money would be on #14 but really don't know.

 

[Higgy]

@SamCF
Your thread is what inspired me to pull ribbon out of the intake. Did you have anything like this happen after you pulled the ribbon? Ever hear of anyone else with this issue? Could it be high intake manifold temp causing the alarm?
Thanks

 

[Higgy]

I'm not the most experienced jetboater but I don't think it is cavitating. The boat still has good acceleration. The RPMs go to 7800 with a cool engine and then slowly fall to 7200. The engine has acted that way from day one which I find very aggravating.
I never had this issue last year before I pulled the spark arrestor. I'm thinking I should pull the impellor and if that is undamaged and no obstructions maybe I should just put the stupid ribbon back in...

 

[Higgy]

I'm also tempted to order a big intercooler.. I don't know... probably gonna be awhile till I get to launch the boat again.

 

[SamCF]

I've never had an overtemp warning, but my engine does run hot. I was using YDS to monitor boost pressure and throttle position and noticed my temps climbing to 230 on long full throttle runs. I did some cooling upgrades to the engine with no change in temp readings. Too much cooling on these will cause gas to get in the oil, so don't go crazy with cooling upgrades.

It's probably clogged somewhere. The cooling system is pretty complicated with several entry and exits for water. I'll try to find a diagram.

If you think the sensor is bad, you could take temp readings on the head in different spots with an infrared temp gun to see if it is actually getting hot.

 

[billyb]

Shouldn't this still be under warranty? If so, it's probably a long drive to get it resolved by a dealer. I know it sucks, but they can prolly diagnosis this and fix it better.

 

[SamCF]

When you hook up the hose to the flush port, I don't think it flushes the whole system very well. You might have to study this and figure out a way to flush/backflush to clear any obstruction.

 

[Higgy]

I'd rather tinker with it myself than turn it over to them. In my mind that would be giving up. I've never worked on boats put I've been a pro diesel tech for 15 years so my pride is gonna take a beating if I can't fix this little four cylinder
Sam and Swatski are probably right in that it has a partial clog somewhere.

 

[Higgy]

@SamCF
Alright thanks Sam. I appreciate it.

 

[buckbuck]

Higgy,
With good stream coming out the pee holes I would cast doubt on a cooling water issue. I am not familiar with the 1.8 engines but I think you have two temperature sensors that will trigger the overtemp. One to monitor the engine block and one for the exhaust manifold. Using the YDS will give you an understanding which is giving the signal. Come to think of it you may have one on the supercharger. I found on my boat that shooting the oil filter with an infrared gun gives a reading close to the engine block temp reported to the computer.
We are here to help you so keep us posted.

 

[4x15mph]

i would not rely on pee holes to tell you that the cooling system is working 100%. I know my boat is different but cooling occurs around the exhaust chamber that is after the pee hole line. Flush line also misled me when I worked through a cooling system on my boat.

I think you have water strainers/screens on the jets of your boat. Have you checked that for obstruction and tried running some weedwacker cord through that? I would also poke the cord through the pee holes for a few feet since it could still have a slight obstruction.

It is only an opinion but I would not delete the ribbon or consider any more non OEM mods such as intercoolers, etc. You will likely trade-off reliability let alone warranty (?)

 

[swatski]

I'm not the most experienced jetboater but I don't think it is cavitating. The boat still has good acceleration. The RPMs go to 7800 with a cool engine and then slowly fall to 7200. The engine has acted that way from day one which I find very aggravating.
I never had this issue last year before I pulled the spark arrestor. I'm thinking I should pull the impellor and if that is undamaged and no obstructions maybe I should just put the stupid ribbon back in...

I deleted my initial response, just pointed out some possible cooling inefficiencies as a culprit. I agree with what others have said. But, lets not overthink the problem.

Sure it could be temp sensor, and something bigger after that. But, by @Higgy report, he has had overheating issue (aka heat soak in SHOs) from day one. Classic variety. Never reported for 1.8l N/A engines, to the best of my knowledge. Most guys who push supercharged 1.8l engines beyond what they come with from the factory consider cooling upgrades. It can be tricky, as @SamCF pointed out, but the SHO intercooler and oil cooler is crap so it needs the extra cooling. They improved the design of the oil cooler with the SVHO. I don't think there are any risks associated with IC upgrade (to a larger unit used in SVHO). RIVA has kits, too.

There are many way to skin that cat, for added speed and/or consistency. Putting the ribbon back in is one of them. May be a good idea if heading back to dealer for a warranty check.

 

[Higgy]

Yeah I think the most reasonable and obvious thing to do is check the impellor and strainer and if it looks good put the ribbon back in and see what it does. It'll probably be a month or more till I get to launch again so I won't have any results for a while.

 

[Bill D]

I'm not a mechanical guy, but isn't the function of an inter cooler to cool the air that has been through the supercharger before it gets to the engine intake in order to let it become more dense and compressed (aka more oxygen rich)?

For me, getting my hands on a YDS and finding out where the alarm was coming from and confirming that it is a real alarm, not a faulty sensor, would be my first route.

 

[SamCF]

I agree with Bill. Confirm that the sensor isn't the problem. I posted the cooling flow diagram to show that there are many entries and exits in the cooling flow. Clearing a blockage is not as simple as hooking a hose up and confirming flow through the pissers.

 

[Higgy]

@SamCF @Bill D
I would love to be able to do that but I don't have YDS and I don't have a laptop anymore... mine took a dump several years ago and I never replaced it. Seems like a several hundred dollar investment to get YDS...

I can't help but think that I caused this issue by removing the ribbon. If it did not do this last year and performance is good until it derates...

As Bill stated the function of the intercooler is cool the intake charge... so as we all know the factory IC sucks... and the ribbon is a restriction in the intake. So by removing the ribbon I have decreased the amount of time the intake charge spends in the already inefficient intercooler. Meaning the intake charge is now not cooled properly. Hotter air entering the cylinder means hotter air exiting the cylinder to trip the temp sensor in the exhaust manifold.

I also have not stated that when I removed the ribbon I replaced it with the aluminum spacer from R&M. So maybe that little thing works as advertised and has sped up the intake air so much that the intercooler cannot do it's job and now the heat sensor in the exhaust is setting the alarm. Maybe that's why they recommend upgrading the intercooler at the same time?

It just seems to me that I've altered the engine from OEM and now I have an issue. Maybe I should put it back the way it was and see if my issue goes away before I start chasing my tail and buying more stuff. I also won't know what really caused it if I do too many things before I launch the boat again.

 

[Bill D]

Good point, you could try to go back to stock to see if the alarm is not a false alarm and is a result of getting hotter air in the engine faster. If the alarm goes away and you're ok with performance, perhaps problem solved. If that doesn't clear it up, at least you have eliminated something. If all else fails, when the weather breaks you're not too far away from some fellow members. @swatski has done a hell of a lot of research on the single engine model and @jcyamaharider has known these boats for a long time. We're here to help figure this thing out!

 

[Higgy]

Yeah we'll get er.

This weekend did not turn out as planned. My boat is screwed up and Dale Jr. wrecked his car...
At least we got out on the water for a little while.

 

[jcyamaharider]

I will have my YDS next week. Yeah we will get it straightened out. Also maybe try flushing the engine on land and see if that helps. It helped a fellow jetboater one year at Shelbyville. Well, that, rain , jello shots, the threat of drinking a natural light, and some cool friends. LOL @OperationROL