Water in Oil and Cylinder

1995 Chaparral 2330 with 5.7L EFI
Boat was seldom used by previous owner who had for 3 years. Ran 3 times went to go do maintenance since other owner said he never done any. Boat ran great the 3 times I took it out for about 1 hour on 2 and 3 outing each time no hard running mostly put putting up and down river. Upon running motor to warm up for first oil change hose came off flush muff and motor got to about 220 deg. shut down re-hooked hose started and temp went back to normal doing oil change found milky but no excessive fluid changed oil ran for a few seconds to fill oil filter to check level. talked to some friends recommended to do another oil change to get all milky oil out. Now the fun part went to go start 2 days later to warm oil for removal and engine hydro locked pulled plugs water in #5 and #6 only. new riser and exhaust manifold ordered arrive 2/25/13. Put pressure on all cylinders and they were tight Compression was good on all except 1 and 2 were low?? again motor ran great before hydro lock happened when idling in driveway with flush muffs on never ran hot. any other suggestions would be appreciated.

Re: Water in Oil and Cylinder

Pressure test on cooling system. . . You should be able to hear the leak.

Re: Water in Oil and Cylinder

fireftr1990 said:

1995 Chaparral 2330 with 5.7L EFI
Boat was seldom used by previous owner who had for 3 years. Ran 3 times went to go do maintenance since other owner said he never done any. Boat ran great the 3 times I took it out for about 1 hour on 2 and 3 outing each time no hard running mostly put putting up and down river. Upon running motor to warm up for first oil change hose came off flush muff and motor got to about 220 deg. shut down re-hooked hose started and temp went back to normal doing oil change found milky but no excessive fluid changed oil ran for a few seconds to fill oil filter to check level. talked to some friends recommended to do another oil change to get all milky oil out. Now the fun part went to go start 2 days later to warm oil for removal and engine hydro locked pulled plugs water in #5 and #6 only. new riser and exhaust manifold ordered arrive 2/25/13. Put pressure on all cylinders and they were tight Compression was good on all except 1 and 2 were low?? again motor ran great before hydro lock happened when idling in driveway with flush muffs on never ran hot. any other suggestions would be appreciated.

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Ayuh,.... Welcome Aboard,... Did that happen, before, or after the hydro-lock,..??

Re: Water in Oil and Cylinder

You mean pressure test intake manifold I didn't mention it is seawater cooled ? And milky oil was noticed before hydro lock that was noticed when I went to warm engine to remove the oil I put in 2 or 3 days later. other than that boat ran great no miss or anything only thing that happened on last outing was idling high meaning 1300 or 1400 rpm when first launched shut motor down restarted and it idled just fine

Re: Water in Oil and Cylinder

On the initial warm up prior to oil change: Did the boat "diesel" when you shut it off? Meaning did it try to continue running after the key was switched off?

Re: Water in Oil and Cylinder

I suspect that the PO had the problem before he sold it to you, and therefore did not use the boat much. Hydro-locking can be either water coming from the exhaust during idling (reversion) or can be water from the intake manifold or the cylinder head. The trick is to find where, so that you are not throwing parts and labor at the engine blindly.

If you can seal off the water hoses to the exhaust manifolds, then you could apply compressed air to the sea water inlet hose and get a psressure check of the engine itself. You would separately have to check the exhaust manifolds in that case.

Since you got water on both sides of the engine, it may mean an issue on the intake side of the engine.

In addition to the pressure test, you could do a compression test and cylinder leak test to see what the condition of the engine is at this point.

I had a 7.4L Mercruiser hydro-lock on the port side . . . bent a bunch of connecting rods, etc. At that point, I decided to throw in the towel on the engine as there was too much damage.

Re: Water in Oil and Cylinder

Engine shut down as normal I changed the oil and filter started back up for 30 seconds turned back off after that didn't try and restart for 3 days that is when noticed hydro lock. Poured acetone in one exhaust manifold no leak did not do the other or the risers. Put air pressure in all cylinders and the held pressure, waiting for friend to lend me pressure gauge to check compression other than that waiting on new manifolds and risers

Re: Water in Oil and Cylinder

An intake problem doesn't make a lot of sense with #5 & #6 having water. The intake connects #5 with #8 and #6 with #7.

Re: Water in Oil and Cylinder

wrench 3 said:

An intake problem doesn't make a lot of sense with #5 & #6 having water. The intake connects #5 with #8 and #6 with #7.

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Yup, could the the heat crossover passage passing some water to the other side . . . if the intake manifold has the crossover passage. The only thing in common is that #5 & #6 are the third cylinder on each side . . .

Re: Water in Oil and Cylinder

New manifold and riser delivered today will install tomorrow praying that was the problem will post when done and if it turns out to be the intake hope just the gasket part is no longer available anywhere

Re: Water in Oil and Cylinder

fireftr1990 said:

New manifold and riser delivered today will install tomorrow praying that was the problem will post when done and if it turns out to be the intake hope just the gasket part is no longer available anywhere

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Divine intervention would be good. . . .

Re: Water in Oil and Cylinder

Well I guess the prayers helped New Exhaust manifold and risers on so far so good no water in oil ran great. work tomorrow for 24 hours will check oil and crank it back up on Friday Thank you all for the Help and sugestions