water under valve cover

[jmacgowan]

I have a 92 chris craft 5.7 omc, when testing/adjusting new carb I discovered water spitting out pcv hose into flame arrestor which seemed to be the reason for the engine to bog down when throtteling up. Next the boat would not stay running long enough to get into gear, so after the carb would not restart so I waited an hour, then it started up fine and it ran great at full throttle for about 45 mins when I realized the new noise I was hearing was the lower unit losing the upper gears! I have "mayonaise" water in the oil under the valve cover but do not seem to have oil on the dipstick, any suggestions?

 

[Alpheus]

Re: water under valve cover

How long since last oil change?

Is this the first time you had starting and running issues?

Is the engine using more oil than usual?

Have you been running the boat alot on very short hops and letting it sit for awhile?

Are both valve covers showing the same signs or is it limited to just on one side?

Some times if you run a boat for short runs it dosent allow the oil to get hot enough to burn the moisture out. This could explain the moisture under the valve cover...

Start off by removing oil and looking for an off color. (milky,hazy, to thick or to thin.) If nothing is noticed in the oil at first glance take an oil sample and let it sit for a day and check for any seperation.

Do a thorough inspection of your exhaust manifolds, risers. Remove your spark plugs and look for anything unusual (carbon buildup,etc.), then do a compresiion test. This should give you a start on diagnosing your dilema. Good luck...

 

[JustJason]

Re: water under valve cover

Pump out the engine oil and look at it. If it's milky you either have a cracked block, a rotted block, a bad intake manifold gasket, or a rotted intake manifold.

 

[T-Bone Coug]

Re: water under valve cover

Not trying to be an a-hole, but it's alot easier to read your posting if you use punctuation. I had to read this 3 times, and parts of it more than that to get any kind of idea what you are trying to say. Sorry, I have no other input on your problem. As they have already posted, more information is needed.

 

[jmacgowan]

Re: water under valve cover

oil is 2-3 yrs old but the run time is no more than 3 hrs, due so breakdowns.

this is the first time with these current issues,

the engine oil was overfilled due to being topped off while having trouble on the water. During a test run this past summer the carb had been giving trouble, then the valves started rattling, when i shut down to check the oil the dipstick showed very low, so i put in three quarts of oil which brought the oil level to normal on the dipstick, now upon draining I find 8 quarts of oil, but no evidence of water in the oil

the boat has been giving trouble over the last 3 years it has seen the water 5-6 times totaling 2-3 hours

visual inspection of exhaust manifolds and risers show nothing obvious

spark plugs (Approx 1-2 hours run time) all look good no build up and all the same color

compression test in firing order
#1 150
#2 130
#3 155
#4 160
#5 140
#6 160
#7 115
#8 105
any suggestions ?

 

[mkast]

Re: water under valve cover

visual inspection of exhaust manifolds and risers show nothing obvious

Would that be an exterior surface inspection?
What temperature does the engine run at, fully warmed up?

 

[JustJason]

Re: water under valve cover

Cylinders 7 and 8 are your main problems. You need to do a leakdown test on those 2 and see where your compression is going. If either 1 has an intake valve problem your going to be chasing your carb up and down, but the problems not in the carb.

The valves probably started rattleing because you lost your oil pressure, and the lifters collapsed. So you need to find out where 2+ quarts of oil went. You either burn't it or you leaked it. Again possibly in cyls 7-8.

Try the leakdown test. But my guess is your going to be pulling the heads if not the whole motor out.

 

[kartman]

Re: water under valve cover

my guess would be that with those compression numbers, you will atleast be putting in a new shortblock if you dont rebuild. somethings not right inside. my guess would be a cracked block. they usually crack on the starbord side.

 

[JustJason]

Re: water under valve cover

they usually crack on the starbord side.

Water does not know it's left from it's right. V8's Crack on both sides + right up the middle to.

 

[Alpheus]

Re: water under valve cover

they usually crack on the starboard side.

Just fixed one this summer with cracked block on port.

As for cylinders 7 & 8 they are the rear cylinders on both sides.

Do the leakdown test. That will answer all of your questions...