Mercruiser 5.7 Water In Cylinders

[gndultimate]

I have a Mercrusier 5.7. I Put the boat in the water and drove it like 15 min to my slip and she drove great. Once at the slip I had her running for an additional 15 mins. Water temp was perfect everything seemed fine. When I went to start it the next day she was not turning over. I pulled all 8 plugs and all had water in them. I was told to change risers and manifold, which I did, I changed oil at least 4 times and she was running great. Now same problem except only one side of engine was loaded up with water. I am lost.

 

[gndultimate]

Re: Mercruiser 5.7 Water In Cylinders

SOMEBODY HELP!

 

[Haut Medoc]

Re: Mercruiser 5.7 Water In Cylinders

Welcome to iboats.....
You changed the riser & manifolds on both sides?.....
Is there a possibility that the engine was damaged by poor/no winterization?........
If not, pull the riser on the side with the water in the cylinders & check that the mating sufaces are good & the gasket is not damaged.....
Put a new gasket on......​

 

[gndultimate]

Re: Mercruiser 5.7 Water In Cylinders

I did a compression test on all 8 cyl yesterday and all 8 have almost 180lbs of compression. I puilled the riser off of the side with the water and inspected the gaskets and it looks fine. If there was damage to block or heads would the compression be lower in at least one cylinder? Any advice will help..... Thanks

 

[bjcsc]

Re: Mercruiser 5.7 Water In Cylinders

So are you saying you didn't winterize it?

 

[RubberFrog]

Re: Mercruiser 5.7 Water In Cylinders

Did you replace the riser and manifold on both sides?

There's no point at us guessing at. Give us the details.

 

[Coors]

Re: Mercruiser 5.7 Water In Cylinders

Did it diesel upon shut down?

 

[gndultimate]

Re: Mercruiser 5.7 Water In Cylinders

Both side risers and manifolds were replaced. Took the intake off and did a leak down test. One side is good the other isnt. Took the heads off last night and are having them checked. I have my fingers crossed that the block is not cracked. There are flaps in the Y pipe. There is only half of flap on the bad side and an almost not good one on the other side. Can this have anything to do with the water? Just checking all fields.

 

[Coors]

Re: Mercruiser 5.7 Water In Cylinders

Why did you change the oil 4 times? Was there water in it?

 

[gndultimate]

Re: Mercruiser 5.7 Water In Cylinders

There was lots of water in the oil.