140 Mercruiser getting water in cylinder 4

[RNunnelly]

hello,
I am new to this forum, I just bought a 86 sea ray Seville, the oil mixed with the water, so the oil was milky white, I bought the boat cheap because of this issue. it has a 140 mercruiser. So first of all I did a compression test on the motor, 1-130 2-135 3-130 4-0, so after a little bit of looking around I found the exhaust valve stuck down, so I removed the valve cover, and I seen the milky white oil on the rockers.
So I sprayed some lube on the cylinder 4 exhaust valve and I got the valve to move again :happy:
Put everything back together and did a compression test again. 1,2,3, all the same as stated before, cylinder 4 was 150. (kind of high)

Changed the oil and put fresh oil in, ran it with the water on for about 10 min.
removed spark plugs again and all were good but cylinder 4. I removed the plug and had some water on it. I turned it over with the plug out and out shot some water.

So as of right now I am going to take off the riser and manifold, witch looks semi new, prev. owner said he bought new one from ebay a few years back. maybe gasket issue??

Just would like some info to make sure im in the right direction. thanks

 

[Kronoss]

Sounds like you need a new manifold and maybe a riser. Take the manifold out and fill the water jackets with water, and see if it stays level, and none drain into the exhaust portion.

 

[RNunnelly]

ok awesome, thank you for the very quick reply. they both look really good from the outside, not rusted, but I will take them off I'm hoping tonight if not then tomorrow after work. and I will fill those water jackets.

 

[alldodge]

hello,
I am new to this forum, I just bought a 86 sea ray Seville, the oil mixed with the water, so the oil was milky white, I bought the boat cheap because of this issue. it has a 140 mercruiser. So first of all I did a compression test on the motor, 1-130 2-135 3-130 4-0, so after a little bit of looking around I found the exhaust valve stuck down, so I removed the valve cover, and I seen the milky white oil on the rockers.
So I sprayed some lube on the cylinder 4 exhaust valve and I got the valve to move again :happy:
Put everything back together and did a compression test again. 1,2,3, all the same as stated before, cylinder 4 was 150. (kind of high)

Changed the oil and put fresh oil in, ran it with the water on for about 10 min.
removed spark plugs again and all were good but cylinder 4. I removed the plug and had some water on it. I turned it over with the plug out and out shot some water.

So as of right now I am going to take off the riser and manifold, witch looks semi new, prev. owner said he bought new one from ebay a few years back. maybe gasket issue??

Just would like some info to make sure im in the right direction. thanks

The 150 on number 4 is what it should be with some oil in it (you sprayed lube on number 4 exhaust). Checking the manifold and risers is a good start, but I'm thinking you have a cracked block or head, first guess would be the head.

 

[RNunnelly]

when I was doing the compression test, it still had the milky oil inside. maybe now that I have new oil in it I should do another compression test?

 

[alldodge]

when I was doing the compression test, it still had the milky oil inside. maybe now that I have new oil in it I should do another compression test?

It won't hurt to run another but I don't see anything else showing up. If it's not the exhaust manifold or riser, it could still be a cracked head and not show up during a compression test, if the crack is in the valve guide area behind the valve seat

 

[RNunnelly]

Ok so I removed the head. And found the block has a pin hole and hair line crack on cylinder 4 wall. My question is can I get a car block and put brass freeze plugs in and use that block or? Thanks again

 

[alldodge]

Ok so I removed the head. And found the block has a pin hole and hair line crack on cylinder 4 wall. My question is can I get a car block and put brass freeze plugs in and use that block or? Thanks again

Yes that will work if your just using the block. If your going to use the entire engine need to look into other areas. Make sure to use a marine gasket set. Might want to check into long and short block prices and determine if the overall cost.

 

[RNunnelly]

But what vehicle has that block?

 

[Bt Doctur]

no vehicle has that 4 cylinder

 

[RNunnelly]

What engine will fit the head I have? Only the 140 or?