Water In Cylinders and Oil

[scmcgo]

I sure hope you folks can help with a problem on my 2003 GTX 4-tec SC

Twice now my ski has not started due to water in the cylinders. Here are the circumstances.

Ski was running rough on a short trip.
Pulled the plugs and found number 1 slightly water fowled.
Replaced plugs and it ran great on the trailer.
Did a compression check and all 3 were within 2 lbs. of 140.
Replaced jet pump, drive shaft with new seals and bellows, rebuild SC (overdue repairs).
Ski ran great for two days of intense usage.
Shut it down for an hour and it would then only crank without starting.
Towed it to the ramp and took it home.
Pulled plugs and found slight water fowling in all 3 cylinders and milky oil.
Dried cylinders and plugs, engine started right up and sounded great.
Changed oil three times.
Put ski back in water to test and run vigorously to dry remaining moisture.
Brought home to flush and it wouldn’t start.
Pulled plugs and found water fowling and milky oil again. Number two cylinder had standing water in it.
During the entire time, there was never any water in the bilge.
The water in the cylinders is clear (not antifreeze) and I’m not loosing any coolant.

I’m at a loss right now. The first time it died, I thought we got some water ingestion that I didn’t know about (Riva intake system). The second time was only me and a very dry run. My next thought was the first time was water in the fuel, then the towing forced water in, but that doesn’t explain the second failure.

Through all the flushing, running and oil changes, the cooling (flush) hose was always off whenever the ski was off (ski on then water on, water off then ski off).

Thank you in advance for any help you can provide.

 

[XP 787]

Does that ski have an intercooler? If so it may be leaking into your intake manifold.

 

[scmcgo]

Thank you for the quick reply, XP. No, the 2003 does not have an intercooler.

 

[Coastiejoe]

Can you tell if it is water or antifreeze?

 

[scmcgo]

The water in the cylinders is clear (not antifreeze) and I’m not loosing any coolant.

 

[Coastiejoe]

Ok,, I don't know the 2003 system without an I/C very well. That said, I would believe there needs to be something that acts like the I/C on the later engines. If I had to guess, I would bet that the "Raw Water" (raw water is what the ski is running on, Lake, ocean ect ect), passes through the intake to create a temperature differential so that the air is more dense before it gets into the cylinders.

I may be totally wrong, but it just seems that there needs to be a temperature differential.

So, if I am correct, then I would think that the intake is cracked and leaking water into the air intake side.

PLEASE do not take my thoughts as gospel just yet. I want to do some digging on this to see how the 2003 system works..

 

[XP 787]

Saltwater ski? You may have a bad exhaust manifold.

 

[Coastiejoe]

Saltwater ski? You may have a bad exhaust manifold.

If it is a bad exhaust manifold, how would this let water into the cylinders? I am not questioning you, just questioning it all as I am not seeing the connection from the raw water to the block and the cylinders.

The OP also said it is in the oil. The 4-tec is a closed loop system. So if he is not getting Antifreeze in the engine, how is the raw water getting into the engine?

 

[XP 787]

In the 4tec raw water cools the jpipe,exhaust manifold,and intercooler. In most cases the intercooler leaks into the intake but the 185hp skis don't have an intercooler. This leaves the exhaust. The manifold corrodes internally and let's water in when running. This happened to my RXP. Thought it was my intercooler replaced it and same problem. Ski wasn't loosing coolant. Changed manifold and jpipe and it's been fine ever since.

If the OP is 100% sure that it's not coolant then the exhaust is all it could be.

 

[XP 787]

You might be able to pressure test the water jackets in the manifold.

 

[Coastiejoe]

I do agree that it is likely an exhaust and or intake if the cooling water passes through the intake.

 

[ski-d00]

There is no water running through the intake on this ski. It is very unlikely that the exhaust manifold is allowing water into the cylinders. What is much more likely is that it ingested water. The intake manifold can hold a lot of water on the 4tecs. Once water is ingested, it tends to stay in the intake manifold and keep causing water ingestion problems. Take the intake manifold off and remove all the water, then try again.

 

[Coastiejoe]

What is much more likely is that it ingested water. The intake manifold can hold a lot of water on the 4tecs. Once water is ingested, it tends to stay in the intake manifold and keep causing water ingestion problems. Take the intake manifold off and remove all the water, then try again.

I did read this morning in the manual that to get the water out of the manifold it needs to be removed. So I will agree that, if it is ingested water, this is a good place to start..

 

[scmcgo]

Thank you very much gentlemen. I mulled this over last night while looking at the schematics of the cooling and exhaust systems. I came up with a leaking exhaust manifold as well, at least as one possibility.

The ski has seen nothing but salt water for the last 10 years. I flush it religiously along with hosing down the engine and fogging it with MMO. I know this doesn’t help the internals, however.

Could you please confirm my understanding of the raw-water cooling circuit so I can better pin down how water may be getting in through the exhaust, if it’s that? The raw water is pumped around the exhaust manifold, but the exhaust is sealed away from it. Downstream of the rear cylinder, the water then mixes with the exhaust and is expelled together. The running engine keeps water from back feeding into the gas-only portion of the exhaust manifold. The J-tube prevents water from back feeding while the unit is at rest. Does this mean that the two mufflers and all the plumbing downstream of the j-tube are often full of water?

As far as what I’m experiencing, assuming a leaking exhaust manifold is the problem; when the ski is shut down while sitting in the water, raw water is leaking into the gas-only portion of the exhaust. It is then flowing into the cylinders. The oil contamination is coming from water flowing past the rings into the sump. Does this make any sense?

I just saw the two new posts. Water ingestion was my first thought but I didn’t know the intake could hold enough water to cause subsequent issues. I strongly believe that no water got in through the spark arrestor. That would leave the water source as my hosing down the engine after usage. I’ve been doing that for 10 years now. Maybe I’ve developed a leak that is now allowing water to seep into the intake.

I’m changing out the oil again now and drying everything out. It sounds like I need to start pulling in and out manifolds.

Again, thank you for your help. I’m open to any other suggestions.

 

[scmcgo]

I found the problem. It was in fact a hole into the exhaust from the surrounding water jacket. Thanks to all that help steer me in the right direction.

 

[Coastiejoe]

Very good. Great learning excessive.

 

[XP 787]

Awesome glad you got it figured out.