mercruiser 454 losing oil out the exhaust

[bolo78910]

hello iboats, am here trying to help a friend. at the start off the season his boat ran great, last week he got over heat , the culprit was the seawater pump impeller. he change the impeller , took it out for a run when the oil presure start to drop, the enine lost about 5 qt of oil . with the engine running you can see the oil sheen on the water, we replace the engine oil cooler with a new one but we still have the same problem. under load its also over heating too. apart from the cooler where else the engine oil disapear to. no oil is in the bilge, the heater hose that goes to the heater has oil in it mis with water. the oil in the crankcase is clean no milk shake. your thought guys thanks.

 

[bolo78910]

by the way the enging has no knocking or misfire it sound great.

 

[Larken McRorie]

Sounds like a blown oil gasket to me, but I'm not sure. Sounds like you need to have it looked at.

 

[Rick Stephens]

Run a compression check.

 

[tpenfield]

+1 on the head gasket. Compression test and cylinder leak test would be in order to help confirm. when you pull the spark plugs make note of any differences in appearance, etc.

 

[Scott Danforth]

time for a compression and leak-down test.

with the overheat, it could be bad head gasket, toasted rings, bad valve seals. as Ted mentioned, when you pull the plugs for the compression and leak-down tests, inspect them.

 

[bolo78910]

Thanks guys , he told me pull the valve cover today and it's milkshake there. , For some reason it's not milky in the oil pan. As you guy mention it might be a head issue.