Water in chamber and crankcase, please help!

[lanceswaney]

I have a 79 Mercruiser 305 ci, 228hp that I've had for 4 years with no actual motor problems until now. I noticed that my rpm and speed was down. Otherwise, the engine ran fine and did not overheat at all.

I checked the oil and it was a carmel color so I new some water was in the oil. I pulled the plugs today and about 6 to 8 ounces of water poured out of the right side plug, the second back from the front. The plug was really wet and the gap was completely closed so I assume there was no ignition and I was running on 7 cylinders. With plugs out, the compression readings were all 130 to 142 psi, exept the cylinder next to the one with water had 117 psi and the one with water had a higher 152 psi reading (which may be from the water). Each time that I cranked the motor for the compression readings, the chamber with water spit out several ounces of water. So It seems as though the water is there in a constant supply.

Please direct me as to the next steps to troubleshoot the origin of the water (exh. manifolds, gaskets, risers, head gasket, cracked block?). Thanks for your time and experience.

Lance Swaney

 

[Bondo]

Re: Water in chamber and crankcase, please help!

Each time that I cranked the motor for the compression readings, the chamber with water spit out several ounces of water. So It seems as though the water is there in a constant supply

My 1st Guess would be a Failed Headgasket at That Cylinder................

If you were to Pressure Test that cylinder,....
You Should Hear the Air pressure going Into the Cooling System.......

 

[lanceswaney]

Re: Water in chamber and crankcase, please help!

But what would the compression reading be in a cylinder with a blown head gasket? The cylinder is reading actually higher than the others. Could it be corroded exhaust manifold leaking cooling water into the ehaust port? How can I test this?

 

[Don S]

Re: Water in chamber and crankcase, please help!

The water in the cylinder decreases the size of the chamber, thus the higher compression.
Do the leakdown test like bondo mentioned. Of block of the water hoses going to the manifolds and pressurize the cooling system with about 15psi of air and listen at the spark plug hole.

 

[lanceswaney]

Re: Water in chamber and crankcase, please help!

thanks guys, the cylinders have acceptable compression so I suppose head gasket and valves/piston survived. When I took the manifold off, I could see water dripping out of the exhaust gas passage leading to the cylinder with all the water.

Where is the best price for manifolds/elbows? Should I convert from log to center rise? How about aluminum?

 

[Reel Poor]

Re: Water in chamber and crankcase, please help!

GLM has replacement manifolds that have a fair price, good warranty, and are of good quality.

Just google glm manifolds.