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Engine smoking

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Dub454 David Wonchala
Eagle River, AK, USA   USA
I have a 71 MGB-GT that runs great with 135 compression to all cylinders however I am blowing
Non stop blue smoke. I've gone through 5 quarts of oil in less than 300 miles. The engine sat idle for
A few years. No change with Mystery oil treatment. Could my cylinder oiler rings be shot even with good compression or could all my valve seals be shot. It doesn't blow big blue smoke on start up. Mostly with higher RPM while on the highway.

Any suggestions before I replace rings. Thanks

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late 64 Terry O
Milton, Ont, Canada   CAN
constant oil and or blue smoke is the rings........thumbs down

dipstick Avatar
dipstick Kenny Snyder
La Center, Washington, USA   USA
1941 Ford N-Series
1958 MG MGA 1500 Coupe "Rosie"
1970 MG MGB GT "Pat's GT"
1971 MG MGB "Gifted To Me"    & more
Something is malfunctioning with the crankcase ventilation system, oil is being vacuumed out of the crankcase into the intake tract.



Be safe out there.
Kenny

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Dub454 David Wonchala
Eagle River, AK, USA   USA
I also like wondered about the oil ventilation. I took the side plates off and cleaned the metal screen without success, any ideas?

dipstick Avatar
dipstick Kenny Snyder
La Center, Washington, USA   USA
1941 Ford N-Series
1958 MG MGA 1500 Coupe "Rosie"
1970 MG MGB GT "Pat's GT"
1971 MG MGB "Gifted To Me"    & more
The side cover can be immersed in carb cleaner or lacquer thinner for a while then washed, then re immersed and then washed, over-and-over until clean. Eventually the solidified goop in the filter screen will wash out.

In reply to # 3553334 by Dub454 I also like wondered about the oil ventilation. I took the side plates off and cleaned the metal screen without success, any ideas?



Be safe out there.
Kenny

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Ex-Calif Gold Member Dan D
Cincinnati, Ohio, USA   USA
1968 MG MGB GT "Bart - Yellow And Naughty"
1977 MG MGB "Red Betty"
2012 Jeep Liberty "Tank"
2014 Hyundai Accent "Skate"
If you suspect it is coming from the crankcase vent, Disconnect the side cover from the intake and rig it to a catch can and see how much oil you collect on a drive.

5 qts in about 300 miles is like all the oil over one tank of gas.

Isn't the 71 a High Compression engine? My 68 compression checks in the 150-160 range. 135 is lower than my 77.

With that much oil the plugs would likely be badly fouled - How do they look?

If fouled are they all fouled and fouled equally?

Is there any sign of oil in the coolant?

There are more clues to be had here.



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Chalky Avatar
Chalky David White
Coventry, Warwickshire, UK   GBR
Do you have a PCV valve? Is it clean and working correctly? These are known to cause significant oil consumption when they fail.

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