2012 Sea Doo 180 SP Overheating

[Bluewater180SP]

Hello everyone and thank you for any advice/tips in advance. Long story...
I have a 2012 Sea Doo 180 SP that has started having an issue with overheating. I have noticed that it will only shut down on temperature when I operate the boat wide open throttle after about five to ten minutes. The temperature alarm will not trigger if I operate the boat at 6000 rpm or lower. I took it into the local shop and they replaced the temperature sensor stating it was out of range. After getting the boat back we did a boat run of about 119 miles averaging about 25 MPH (heard this is the best for gas consumption) with no issues and with the temperature staying between 190-205. On our way back and almost to port, I decided to open up the throttle and again the boat overheated. I took it back to the local shop where they replaced the thermostat and performed a lake test where they ran it wide open and it overheated again. Now they are telling me that it is a bad head gasket that will need to be replaced and that since the boat has been overheating that the head will probably warp and need machining. I have never noticed or smelled any coolant leaking from the system, nor any loss of coolant from the reservoir. If it was a bad head gasket causing hot exhaust to leak in the cooling system, would it cause an overflow or a hose to burst from the excess pressure? Also, wouldn't this become an issue on the long boat run since with the system pressuring up over that length of time? Any help would be much appreciated before having to spend a ton of cash on a misdiagnoses.

 

[C9R0J0]

If the head gasket is bad, I believe you should see white smoke in the exhaust.

 

[Bluewater180SP]

Thank you for your reply. I do not recall seeing any, but I'll start her up once I get it back to make sure. I also plan on pressure testing the cooling system and see if it leaks off.

 

[Bluewater180SP]

Also, that reminded me of something else. We have had the oil and spark plugs changed when they thought it was the temperature sensor out of range. They didn't mention anything looking out of sorts with the oil. I always ask for my parts to be returned to me and don't recall anything looking wrong with any of the spark plugs. I think I might still have them. Would the spark plugs show any indication of a bad head gasket?

 

[Bluewater180SP]

Here are the plugs.

 

[gb387]

To me they don't look quite right the coloring and the porcelain part around the electrode should be cleaner.... I can't diagnose the issue but again just doesn't look right.

 

[Bluewater180SP]

Thank you for your input.

 

[JPass]

Those plugs do not look good. It's hard to tell from pics, but they almost appear rusted at the very ends.

Has the compression been tested? A coolant system pressure test certainly wouldn't hurt either.

 

[Bluewater180SP]

Thank you for your response.
I have the boat back in my possession and rented a cooling system pressure kit. For anyone who has done this before, to what limit should I pressure the system to and what would be considered a normal amount of loss of pressure? I don't want to blow any of the hoses off the engine. I'm not sure if I should see the gauge slowly go to zero with an head gasket issue or if there would be some amount of pressure within the cylinder that it would equalize to. After doing this, I do plan on checking the compression on each cylinder. Thank you.

 

[Bluewater180SP]

I performed a 5 minute pressure test where it leaked off 22 psi to 19 psi with cap rating of 13 psi, .9 bar. Started boat after test and did not see any white smoke from the exhaust.

 

[Bluewater180SP]

Cylinder compression test:
From bow to stern, 125 psi, 127 psi, 135 psi. Pictures of plugs from all three cylinders with at least 240 miles on them. I had cooling system pressured up while doing the test and did not see any signs of coolant on plugs or in the cylinder test equipment. I am not sure if those pressure are normal for a cold 4-Tec engine. To me it doesn't appear to be a head gasket problem. Any thoughts?

 

[Bluewater180SP]

Plug pics, 2 pics per plug starting from bow to stern. Started engine again after test since cooling system was pressured throughout, still no white smoke from exhaust:

 

[gb387]

Those plugs look just as they should.

 

[Bluewater180SP]

Thank you for the reply. I am wondering if I should try to flush my cooling system? Maybe there is some type of restriction in the ride plat that causes my engine to overheat at high RPMs? I'm not sure what type of flush to use that I can obtain at an auto parts store?

 

[C9R0J0]

I don't think you have a head gasket problem either.

Seems like a flow problem.

Also have you tested the fluid itself? I'm not sure if it's significant enough to cause overheating, but I believe too high an anti-freeze to water ratio will provide less cooling ability than the proper dilution.

 

[JPass]

Plugs with 240 miles on them? I'm not sure what you mean by that, but the plugs on a 4tec should be changed yearly. They're cheap and the 4tecs are known for being finicky about plugs. Change them annually along with the oil and filter, regardless of hours on them.

You can try buying a cheap IR thermometer and start checking the temps of everything to see what the actual temps are through the exhaust and engine coolant systems.

Typical compression check tests are looking at 2 things. One being the actual pressure (anything below 100 psi is questionable) and also the difference between the highest and lowest cylinder. This difference is typically limited to 10%. So in your readings we can see you're near the threshold with the 125 vs 135 psi readings.

Was the engine warm when the compression test was done? Did you hold the throttle wide open when performing the test?

Has the coolant ever been flushed? Maybe there's a restriction somewhere?

 

[Bluewater180SP]

Thank you for the reply.
C9R0J0:
I had a service performed on 06/11/19 where I would think they would have tested the antifreeze, but I probably shouldn't assume anything. I do plan on doing a flush on the cooling system and replacing the antifreeze after.

JPass:
I had the spark plugs, filters and oil replaced on 06/11/19. After that we did a boat run from Galveston, Tx to Lake Charles, La and back, approximately 240 mile trek, 8 engine hours. I was attempting to give an idea of the amount of use the current plugs had on them versus the older ones that I uploaded on Thursday that came out of the engine on 06/11/19. The engine compression test was done with the motor cold. I am unsure why throttle position would matter? I have read about the 10% threshold, but would any of those pressure readings make you think that there is a head gasket issue as the shop I took it to diagnosed? I am a bit new at this and not really a mechanic, if you couldn't tell already. Ha! I do plan on performing a cooling system flush as soon as I have a chance. I read from a post that Valvoline Zerex Super Radiator Flush is what is best to use. Is that what you would recommend?

Also, Any insights, thoughts or recommendations on how to perform a flush on the boat would be greatly appreciated since the directions given are for automobiles.

 

[JPass]

Bluewwater180SP: Testing compression with WOT Here is a quick read on why.

The difference in pressures between the lowest and highest are close, but not yet at the threshold. That's why I asked if the engine was hot or cold and the position of the throttle. I've seen variations in pressure readings in those situations. Best is always on a warm engine with WOT.

At this point, I'm not sure how else to help you out. Flush the coolant and make sure the system is purged of air and try again.

I still think you may have a restriction or a flow issue (maybe faulty water pump?).

Keep your testing coming, hopefully we can get to the bottom of this.

 

[yacht1255]

Спасибо за совет

 

[Bluewater180SP]

Update: I took my boat to a different shop to get another opinion on why the engine is overheating. The first thing they came up with was the water pump. I didn't question their diagnosis and they replaced it. Took the boat back out and it is still overheating at wide open throttle. Took it back to the repair shop and now they are telling me it is due to the supercharger and that it is leaking water. I can not see how that would be. Does the supercharger on the 4-Tec engines have a water jacket on it? How would the water flow around the supercharger for cooling? Here is a schematic they sent me:

 

[C9R0J0]

No, there is no water jacket.

The intercooler can leak, but that should have no effect on the cooling of your engine. The 2 systems aren't connected. The engine has a closed loop system and intercooler and exhaust are open loop.

I could see a leaking intercooler maybe causing your exhaust to overheat if it's not getting enough water. If this was the case though your engine would also be running poorly I'd think.

 

[Bluewater180SP]

C9R0J0,
Thanks for your response. I will be retrieving my boat from them. It doesn't seem that they are really reputable. I really started questioning their ethics when they sent me that diagram, but thought to ask just to make sure. I mentioned to them that I couldn't see how water was leaking from the point they showed and perhaps it was the intercooler, but they were adamant that it was leaking from the place they indicated to saying the water was filling the boat and would kick on the bilge pump. Which is an issue I never had before.

 

[JPass]

Have they pressure tested the cooling system after installing the new water pump? Did they check the thermostat?

If you don't already have one, get an IR Thermometer and check the temps of the hoses throughout the cooling system and also the temp where the temp sensor is located as well.

Cooling System Flow

 

[Bluewater180SP]

They replaced the thermostat with one that is set for 160 degrees. That's the second one installed since the issue started. I do not know if they pressure tested the system. I pressure tested the system back on 7/15 with the results listed in the thread above.

 

[JPass]

IR Thermometer seems like a good thing to start using at this point. Now that you know how the coolant flows, you should be able to measure the temps of the hoses and engine case where the coolant flows through.

A few good readings will be the temps before and after thermostat (until thermostat opens), then I'd want to know the temp of the coolant before and after the heat exchanger (at various speeds).