Long time learner from this site, first time poster!
Loosing a quart of anti-freeze after 10 hours of running, milk shake oil
Past 15 years always ran 5 gallons of pink anti-freeze thru it at operating temp before storing next to the house in Oregon.
Getting harder to get on plane over the last several years, top end & mpg remained the same on 1991 3055 Bayliner
Removed radiator cap during warm up for leak down test, slow warm stream flowing then all of a sudden the level starts rising fast, got the cap back on before losing much coolant.
Brought Engine up to temp and radiator level was normal again, flowing fast with No bubbles.
No bubbles at all during the leak down test either.
Didn't go outside of boat to listen for exhaust leaks at transom.
Since no bubbles, wondering if it's the intake manifold gasket leaking?
Would you guys & girls look over this and give me your thoughts please?
Thank you!
Mel
1990 Mercruiser 7.4 Ser. OD433606 Mod. 474B11OCS 860 hours
Compression Test - engine Cold
Leak Down test - engine Warm
Cyl. Cyl.
1 - 125 psi, leak down 2 % valve covers. 2 – 120 psi, leak down 31 % valve covers
3 – 110 psi, leak down 40 % VC & Carb. 4 – 90 psi, leak down 72% VC & Carb
5 – 87 psi, leak down 77 % VC & Carb. 6 – 100 psi, leak down 62 % VC & Carb
7 – 120 psi, leak down 8 % VC only. 8 – 120 psi, leak down 10 % VC & Carb
Loosing a quart of anti-freeze after 10 hours of running, milk shake oil
Past 15 years always ran 5 gallons of pink anti-freeze thru it at operating temp before storing next to the house in Oregon.
Getting harder to get on plane over the last several years, top end & mpg remained the same on 1991 3055 Bayliner
Removed radiator cap during warm up for leak down test, slow warm stream flowing then all of a sudden the level starts rising fast, got the cap back on before losing much coolant.
Brought Engine up to temp and radiator level was normal again, flowing fast with No bubbles.
No bubbles at all during the leak down test either.
Didn't go outside of boat to listen for exhaust leaks at transom.
Since no bubbles, wondering if it's the intake manifold gasket leaking?
Would you guys & girls look over this and give me your thoughts please?
Thank you!
Mel
1990 Mercruiser 7.4 Ser. OD433606 Mod. 474B11OCS 860 hours
Compression Test - engine Cold
Leak Down test - engine Warm
Cyl. Cyl.
1 - 125 psi, leak down 2 % valve covers. 2 – 120 psi, leak down 31 % valve covers
3 – 110 psi, leak down 40 % VC & Carb. 4 – 90 psi, leak down 72% VC & Carb
5 – 87 psi, leak down 77 % VC & Carb. 6 – 100 psi, leak down 62 % VC & Carb
7 – 120 psi, leak down 8 % VC only. 8 – 120 psi, leak down 10 % VC & Carb
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