140HP Lots of water in CYL#4

[Fordiesel69]

Looked at an 84' sea ray with a newer 140 engine. Oil was clear before it started, now it is a milkshake. Water was 1/4" on top of #4 piston. How can we find out if it is a head/ block / gasket problem, or a bad manifold? We need to do this without tearing the engine apart.

It was winterized correctly and there are no external cracks.

 

[bonzoscott]

Re: 140HP Lots of water in CYL#4

Not sure how you verified 1/4" water on number 4 without tearing it apart. Change oil, then pull plugs and crank it, see if water coming from other cylinders. If not, replace plugs, start it. If same result, cooling system pressure test is in order.

 

[dubs283]

Re: 140HP Lots of water in CYL#4

How can we find out if it is a head/ block / gasket problem, or a bad manifold? We need to do this without tearing the engine apart.

WAG = cracked head and exhaust manifold/gasket

the only way to know for sure is, uh...take the engine apart - otherwise anyone on this board has just as much luck troubleshooting it from behind a keyboard as you do looking at the motor and guessing

 

[Fordiesel69]

Re: 140HP Lots of water in CYL#4

Not sure how you verified 1/4" water on number 4 without tearing it apart. Change oil, then pull plugs and crank it, see if water coming from other cylinders. If not, replace plugs, start it. If same result, cooling system pressure test is in order.

Brite light down the cylinders + rocking the boat would move the water around enough to see the piston top. Other cylinders looked good.

I also beleive I made a mistake, after draining the water side of the manifold, and cranking with the plugs out, the water kept coming out. So where I made a mistake, is that the exhuast runner of the manifold cannot be drained if it is cracked or rotted. The water typically is under pressure from the water pump aso it can fill fast, but it never drains fast.

So it looks like this is a boat to not buy. Definatly not worth the labor tearing it apart just to see if it needs a head or manifold.

 

[PatrickBoyle]

Re: 140HP Lots of water in CYL#4

If the water is isolated to one cylinder, it's probably not the manifold as the exhaust cavity is shared by all four cylinders. Even if it was leaking into the intake side, it would affect two adjacent cylinders. That being said, checking the manifold for leaks is a simple process. Also, because you're getting water into a cylinder, most likely the block is OK. With that amount of water flow, I'd guess you've got a corroded water jacket in the head. The heads on these motors are a piece of cake to replace.

If you can negotiate a good deal and the hull/outdrive are sound, it might be worth it!