engine overheating/build up in cooling system

[barthjon]

Hello All,

Help I have a 2015 AR 240 and only boat in freshwater. I have had an issue with build up on the thermostats in the pasts. I pulled them out and soaked them in vinegar and life went on. A couple of weeks ago the starboard engine overheated. I cleaned the thermostat and it didnt help. I took it to the dealer and he said that the engine needed to be descaled. They billed me for 4 hours for running CLR through it. I picked it up Friday and after boating 3 hours today the starboard engine overheated again. I would really like to take my family out one last time tomorrow. Is there something I can try in the morning? Should I run more CLR through it. If so should I clamp some hoses. The guy at the dealership said to put a clamp on three different hoses. I can remember 2 of the 3 but not the third. I am also wondering realistically the best process to break that stuff up.

thanks

 

[TimW451]

Have you tested the thermostat to make sure it works? For cars, I used to put in a pot of water and make sure it opened at the correct temperature. You should be able to do the same with these.

 

[Scottintexas]

Have you watched the video in our faq about how cooling water flows?
I might try running it without the thermostat i doubt any flushing you could do in an hour or a day will help
Unfortunately it sounds like you can't trust your dealer, if your even a little comfortable with a wrench you could remove at lwast the anode if not the exhaust manifold to see how dirty it is,
What was your thermostat so dirty with??

 

[barthjon]

Have you tested the thermostat to make sure it works? For cars, I used to put in a pot of what and make sure it opened at the correct temperature. You should be able to do the same with these.

Yes. I have also swapped them to see if I could produce it on the port side.

 

[barthjon]

Have you watched the video in our faq about how cooling water flows?
I might try running it without the thermostat i doubt any flushing you could do in an hour or a day will help
Unfortunately it sounds like you can't trust your dealer, if your even a little comfortable with a wrench you could remove at lwast the anode if not the exhaust manifold to see how dirty it is,
What was your thermostat so dirty with??

I have watched it. If the engine is over heating and I run it without the thermostat won’t I mess things up?

 

[barthjon]

I have watched it. If the engine is over heating and I run it without the thermostat won’t I mess things up?

Also. How do I fix this for good.

 

[Scottintexas]

If you find sediment you could try crankygypsy's closed loop flush in the faq
You might also monitor with a infrared thermometer to compare against the other engine, it would really stink if this was just a bad sensor or you could narrow down where the heat is

 

[TimW451]

You’ve tested the thermostat(s) and they check out okay.
You've switched thermostats between engines and port is okay and starboard stays bad.

You could still try no thermostat as suggested and see what happens, but I wouldn't expect any difference based on the prior two activities. It could help flush out loose contaminates better. (You won’t hurt your engine doing this, it will “over cool it”, so it will take longer to get to temp, but not make it run hotter.)

I wonder if the temp sensor is bad. I’d want to check that by testing it, replacing it, or measuring the temp differently as mentioned previously.

 

[WREKS]

@barthjon Was it during high or low rpm when the overheat occurred?

 

[barthjon]

You’ve tested the thermostat(s) and they check out okay.
You've switched thermostats between engines and port is okay and starboard stays bad.

You could still try no thermostat as suggested and see what happens, but I wouldn't expect any difference based on the prior two activities. It could help flush out loose contaminates better. (You won’t hurt your engine doing this, it will “over cool it”, so it will take longer to get to temp, but not make it run hotter.)

I wonder if the temp sensor is bad. I’d want to check that by testing it, replacing it, or measuring the temp differently as mentioned previously.

Thank you

 

[barthjon]

@barthjon Was it during high or low rpm when the overheat occurred?

High RPMs. I was pulling a surfer

 

[Sean R]

What freshwater lake are you on?

 

[barthjon]

What freshwater lake are you on?

The Shell Rock and the Cedar River in NE Iowa

 

[Sean R]

I only have flushed my engine when I bring the boat home for maintenance. Not an easy task at my marine, got me thinking I should do it more often. I am on Lake Allatoona GA. I feel for you.

 

[WREKS]

@barthjon I would try running it at high rpms, unloaded. It may have an internal build up of sediment, especially if you boat in turbid, high mineral content, and/or shallow water. Running it for several miles, at high rpms (7000) may help flush the cooling water jackets, especially around the cylinders. Whatever built up on the thermostat, may be building up internally. Of course, disregard this suggestion, if you develop an overheat.

 

[barthjon]

To follow up on this. I used Cranky Gypsies closed loop flush and it solved the issue. I put nearly 50 hours on the boat this season and it has performed flawlessly.

 

[Elliott]

What did you flush with - CLR?

I boat in salt so I flush with Salt Off every time; it is a mild acid and soap mixture. I wonder if would help your situation if you used it often to prevent build up; the acid should do the job.

 

[Dixemon]

Since this thread is back from the dead. I had an innocent tangle with a sandbar at mid-low last year. FOR ELLIOT: the cut going from fishtales back over to bell's landing. On the way back my starboard overheated, shut it down and ran back to dock at, Low speed on port.
I flushed on the hose for awhile when I got home, took it out the next day and overheated again after running 5800rom for about 6 minutes. I limped back to dock and headed home with tail between legs and a little frustrated.
So this is how I cleared it. I pulled the thermostat and it was obviously fouled. I also pulled the engine block anode which is a real PITA. I then ran it on the hose with the thermostat/anode removed and the intake hose (black) clamped off to create more flow through the cooling system. I had sand coming out of both holes, not a ton but enough to keep fouling the thermostat if I hadn't flushed it thoroughly. I put everything back together and haven't had a repeat problem for 50ish hrs.
I have the tools to pull the thermostat on the water now, I certainly wouldn't pull the anode, especially on starboard. But the thermostat is easy to remove and clean, and also run the engine with it out briefly. if you have a long way back to shore, I believe this is an option. YMMV

 

[barthjon]

I used the recommended sulfamic solution on this site. CrankyGypsy

I bought the Salt-away for future flushes.

 

[Elliott]

Since this thread is back from the dead. I had an innocent tangle with a sandbar at mid-low last year. FOR ELLIOT: the cut going from fishtales back over to bell's landing. On the way back my starboard overheated, shut it down and ran back to dock at, Low speed on port.
I flushed on the hose for awhile when I got home, took it out the next day and overheated again after running 5800rom for about 6 minutes. I limped back to dock and headed home with tail between legs and a little frustrated.
So this is how I cleared it. I pulled the thermostat and it was obviously fouled. I also pulled the engine block anode which is a real PITA. I then ran it on the hose with the thermostat/anode removed and the intake hose (black) clamped off to create more flow through the cooling system. I had sand coming out of both holes, not a ton but enough to keep fouling the thermostat if I hadn't flushed it thoroughly. I put everything back together and haven't had a repeat problem for 50ish hrs.
I have the tools to pull the thermostat on the water now, I certainly wouldn't pull the anode, especially on starboard. But the thermostat is easy to remove and clean, and also run the engine with it out briefly. if you have a long way back to shore, I believe this is an option. YMMV

So far, I have been cautious and probably mostly lucky, and I have not touched bottom. I have not been to Fish Tails; I am out of Landings Harbor so Crab Shack, AJ's and Tubby's (Thunderbolt) are close.

I looked at Google Maps; that cut does look very small. Good advice on the thermostat.

FWIW, there now are several Yamaha jet boats at Landings Marina - I believe I was the first.. I may eventually try to get everyone together to do something.