Water in oil OMC Cobra 3.0

[BigJohn8651]

Hi, new to this forum. Bought my first boat and have some trouble 89 Four winns 160 with 3.0 OMC Cobra gm block. I am getting a little bit of water in the oil. I do know to check the regular things like manifold gaskets and so on. all gaskets are slated to be replaced, along with pressure testing of the manifold. I am wondering what the possibility's are that i have a cracked block? and also if the gasket kits are the same for the different years of manufacturing of the motor. mine being a 89 boat I am having a little trouble finding gasket kits for that year. boat has had a lot of documented work done to it in the last three years including complete out drive rebuild, new bellows, points, and regular winterizing. Any help or advise would be greatly appreciated.

 

[Bondo]

Re: Water in oil OMC Cobra 3.0

I am wondering what the possibility's are that i have a cracked block?

Ayuh,.... Welcome Aboard,.... Probably 80/ 20, maybe 90/ 10....

How much water are We talkin',..??

 

[BigJohn8651]

Re: Water in oil OMC Cobra 3.0

Ayuh,.... Welcome Aboard,.... Probably 80/ 20, maybe 90/ 10....

How much water are We talkin',..??

Its not too much after a day of running its about a quarter inch high on the dip stick, from regular full. Ordered the manifold gasket kit today, should be going through it in two weeks. Would a cylinder pressure test show cracks in the block?

 

[Don S]

Re: Water in oil OMC Cobra 3.0

On the thermostat housing, remove the hose andblock off the housing where the inlet hose is attacked. Then do the same with the hose going to the manifold. Drain the cooling system and pressure test the engines cooling system. Should hold 15 psi .

 

[KeonHayes]

Re: Water in oil OMC Cobra 3.0

Hi, new to this forum. Bought my first boat and have some trouble 89 Four winns 160 with 3.0 OMC Cobra gm block. I am getting a little bit of water in the oil. I do know to check the regular things like manifold gaskets and so on. all gaskets are slated to be replaced, along with pressure testing of the manifold. I am wondering what the possibility's are that i have a cracked block? and also if the gasket kits are the same for the different years of manufacturing of the motor. mine being a 89 boat I am having a little trouble finding gasket kits for that year. boat has had a lot of documented work done to it in the last three years including complete out drive rebuild, new bellows, points, and regular winterizing. Any help or advise would be greatly appreciated.

Did you ever figure out what was wrong? I am curious to find out what you found.

 

[BigJohn8651]

Re: Water in oil OMC Cobra 3.0

Did you ever figure out what was wrong? I am curious to find out what you found.

Well had the manifold pressure tested and it passed, no cracks. the manifold gasket between the head and manifold was in pretty rough shape. Mechanic said it looked like water was coming in from the carb, seen witness of it pooling in carb and a bit of rust. more than likely pooling water on the cover drips down and collects in the carb. may be BS! Its not a whole lot of water in the oil. but enough to show up. So going to replace gasket change oil and filter and see where it gets me. no signs of block being cracked on outside. keeping my fingers crossed that its not a cracked block some where internal.

 

[KeonHayes]

Re: Water in oil OMC Cobra 3.0

Well had the manifold pressure tested and it passed, no cracks. the manifold gasket between the head and manifold was in pretty rough shape. Mechanic said it looked like water was coming in from the carb, seen witness of it pooling in carb and a bit of rust. more than likely pooling water on the cover drips down and collects in the carb. may be BS! Its not a whole lot of water in the oil. but enough to show up. So going to replace gasket change oil and filter and see where it gets me. no signs of block being cracked on outside. keeping my fingers crossed that its not a cracked block some where internal.

Good luck with that. Hope all goes well.