Portside engine overheating

[Doncore3000]

I think I found the issue causing my engine to overheat. I took it out Saturday and barely made it out of the no-wake zone of my subdivision before I started loosing power and got the temp light on the dash. we were in a pretty safe area so I shut it down and dropped the anchor to check for blockage in the jet pump. There was nothing there so we decided to eat and float for an hour hoping it would restart and go away. Well it restarted but as soon as I got on plane it overheated again. So we limped home and I started troubleshooting all the easy stuff like checking the pissers and nothing even remotely close to a clogged line. I read about a hundred post about overtemped engines and I figured I better start digging into the exhaust system since the stream was really weak on the port side. This is what I found so far...

Thank goodness for eBay, instead of spending $1,000 to replace these two pieces I ordered them used for about $180 total.

 

[WREKS]

Is there any water in the oil?

 

[Doncore3000]

Is there any water in the oil?

Nope, No water in the oil.

 

[WREKS]

Corroded exhaust pipes should not cause engine to overheat. Was there any buildup in the water passageways, or around parts 24 and 25 in this link? Exhaust pipe Is there any strange substance on the thermostat? There is a possible internal blockage in the engine.

 

[Scottintexas]

as we try to diagnose and learn more about everyone's overheating issues,

how long have you owned the boat ?
how many hours are on it ? (do you own a YDS unit)
water type (all salt / 50/50 / fresh only )
what is your flushing routine?

I would definitely check the thermostat and maybe even the anode for a look see,

but with that exhaust port corroded all the through it would really make me nervous and I would at the minimum be checking my oil every trip to confirm no water but I may even pull the exhaust manifold as that's where most members seem to find wall corrode allowing water into the engine,



.

 

[Doncore3000]

I ordered the YDS unit, it should be arriving any day now. I'm very interested to see how many hours are on it too. I'm right on Tampa Bay so it's been all saltwater since I've had it and I'm pretty sure the previous owner also was on salt too. I've owned the boat 2 years now and I'm certain that the previous owner was only diligent about NOT doing maintenance, because everything that isn't new is in horrible condition. I rinse the engines religiously with Saltaway when I pull it out of the water. I'm about a block away from the boat ramp so there's no excuse not to just hook up the hoses immediately. I bought it from a used boat dealer who flipped it, so most things are either recently replaced or on their last leg. All of the bolts and the gaskets looked fairly new. I assume the dealer replaced just enough components to get it running well and turn a profit.

I changed the thermostats on both motors a month ago, mainly because the outer housing was corroding and I wanted to investigate. My suspicion was right, they were both in pretty bad shape and one was stuck open. I changed the anodes on both engines about the same time as the thermostats because the outer shell looked pretty bad, but the actual anode inside was fully intact.

My plan was to trace the problem all the way up to the block and hopefully clear out all the crust along the way. Those two pieces caught me of guard so I kinda got sidetracked looking for replacement parts and by the time I got back in the boat T-storms rolled in. Right now I'm pulling the last piece of the manifold and it's not as bad as I expected.

 

[Doncore3000]

Corroded exhaust pipes should not cause engine to overheat. Was there any buildup in the water passageways, or around parts 24 and 25 in this link? Exhaust pipe Is there any strange substance on the thermostat? There is a possible internal blockage in the engine.

There was build up around some of the passages but none were fully blocked. I honestly haven't seen anything definitive yet.

 

[WREKS]

I know you do not want to hear this but the worst problems I have experienced with overheating are the blocked water jackets in the cylinder block itself. That requires removing the engine, then the cylinder head, then cleaning the water jackets. Hopefully you do not have to go there.

 

[Doncore3000]

I know you do not want to hear this but the worst problems I have experienced with overheating are the blocked water jackets in the cylinder block itself. That requires removing the engine, then the cylinder head, then cleaning the water jackets. Hopefully you do not have to go there.

Yes, I've seen that procedure on the YouTube. That's a little outside my comfort zone. I can do it but not as confidently as all the superficial engine work. Luckily for me I have 2 guys who worked for me in the C-130 engine shop right before I retired in Alaska who are getting stationed right here in Clearwater FL. They're both Real gear heads so reinforcements are on the way. And all I have to pay them with is beer and free rides!

 

[Doncore3000]

Here's what the rest of it looks like...

I just ordered a new starter because it's just sitting there taunting me!

 

[Doncore3000]

This is what the thermostats looked like.

 

[Scottintexas]

great to see the rest of the exhaust manifold doesn't look to bad, once you get the new parts I'd put it back together and see how it runs,

If you wanted to do flush, look in our FAQ section for "cranky gypsy's closed loop flush" it's a little work but being a closed loop it works the flush very well,

these boats/engines have a tremendous upside if you can do a little mtc /trouble shooting as you have done,

.

 

[WREKS]

@Doncore3000 If you have not reassembled yet, you could remove hoses and anode on left side of block and probe with a thin instrument for internal buildup in the cylinder water jackets. Usually that side of the block is more open, but it might show something. The bottom hose is the cooling drain line.

 

[buckbuck]

Sad to see the boat in that condition. Check the three holes in the exhaust where the water and gas meet. They sometimes clog with salt.
Consider watching this video.

 

[Doncore3000]

Sad to see the boat in that condition. Check the three holes in the exhaust where the water and gas meet. They sometimes clog with salt.
Consider watching this video.

Thanks, I've watched this video a dozen times. I came across it before I needed it and looked it up as soon as I started having problems. It's very helpful in gaining an understanding of the cooling system.
I'll be replacing the muffler due to the extremely corroded mating flange on the old one. the "New" piece is clean as a carefully used whistle.

 

[Jgonzalez114]

Sad to see the boat in that condition. Check the three holes in the exhaust where the water and gas meet. They sometimes clog with salt.
Consider watching this video.

Hello, did you ever get this issue resolved? I'm having the same problem. Already replaced all the heat sensors and new anode, I'm running CLR through it like crazy. Trying to avoid taking it to the shop to have the block inspected. That will be a few grand.

 

[buckbuck]

@Jgonzalez114
Check your Y fitting for obstructions. That was my issue.

 

[Jgonzalez114]

@Jgonzalez114
Check your Y fitting for obstructions. That was my issue.

Will do that in the morning. I seem to be getting good water flow through the system. Hooking it up to the YDS software to see which sensor is causing the error.

 

[Brad_Ct]

Our SX230 was getting water in the oil and I traced it back to the seal and hose that were on that section of the exhaust. Our pipes were corroded and I did the same as you and bought replacements off of EBay, I would suggest replacing the seal and hose while you have it apart if you were not planning to.