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Fuel and Engines
Timing Belts and Chains
Ford Explorer XLT
Classic 1964-1978 Ford Mustangs

What should you do when a compression test reveals that compression is below average?


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Wiki User
January 21, 2008 12:20AM

If the difference between the high and low reading is within 10%, it is withing normal specification. If more than 10%, try squirting oil into the low cylinder and retest, if compression comes up , this indicates a bad ring, if not indicates problem is a bad valve.