Compression Test

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The cylinder that has the 119, I'd be concerned about. Squirt a couple squirts of motor oil in that spark plug hole. Let it work in for about 5-10 minutes, then redo your test on that cylinder. If it goes up, it's your piston rings causing your drop in compression, if not it's a leaky valve/valve seat. Normally 10 percent lower from your highest is ok, but you will feel a loss of power. I had a 5.0 Lincoln 1989, that had about 14 pounds lower on one cylinder, I felt the drop of horsepower. Keep us posted what you find after recheck.


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The cylinder that has the 119, I'd be concerned about. Squirt a couple squirts of motor oil in that spark plug hole. Let it work in for about 5-10 minutes, then redo your test on that cylinder. If it goes up, it's your piston rings causing your drop in compression, if not it's a leaky valve/valve seat. Normally 10 percent lower from your highest is ok, but you will feel a loss of power. I had a 5.0 Lincoln 1989, that had about 14 pounds lower on one cylinder, I felt the drop of horsepower. Keep us posted what you find after recheck.


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I can tell it's lost power the past couple mouths and it's also started blowing blue smoke out the exhaust when you get on it. Would that have something to do with that also?
 
Well either way your going to probably have to replace/ rebuild engine. You can have a leak down test to verify rings vs valves, but from what you've described with the blue smoke, and loss of compression, I'm leaning towards bottom end. Do the oil in cylinder with a squirt can. Let us know what you come up with. Problem with buying a high performance car like Mustang, is they rarely led an easy life.


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Well either way your going to probably have to replace/ rebuild engine. You can have a leak down test to verify rings vs valves, but from what you've described with the blue smoke, and loss of compression, I'm leaning towards bottom end. Do the oil in cylinder with a squirt can. Let us know what you come up with. Problem with buying a high performance car like Mustang, is they rarely led an easy life.


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Well I've decided to swap the engine because it's getting worse every time I crank it. And I'm wanting to convert it to automatic when I put the other motor in, how hard will that be?