buddhabanshee Posted January 2, 2016 Report Share Posted January 2, 2016 Just did a compression test today. First cylinder was right around 130 psi and the second was 120. Should I be worried that they are that far off? Sent from my SM-G900V using Tapatalk Quote Link to comment Share on other sites More sharing options...
Bennett131 Posted January 2, 2016 Report Share Posted January 2, 2016 What kind of compression tester are you using? Quote Link to comment Share on other sites More sharing options...
buddhabanshee Posted January 2, 2016 Author Report Share Posted January 2, 2016 I believe it is a BOSCH from O'Reilly auto parts. Sent from my SM-G900V using Tapatalk Quote Link to comment Share on other sites More sharing options...
DEREEL Posted January 2, 2016 Report Share Posted January 2, 2016 First of all I would use a snap on comp tester because they give very accurate readings.Make sure gauge hose fitting is properly hand tightened so the rubber gasket makes a good seal. Also make sure your getting the engine up to operating temp and holding the throttle wide open while checking the compression. Keep kicking it over untill the needle stops moving on the gauge.....the readings on each cylinder shouldn't be more than a few psi difference from one another. Quote Link to comment Share on other sites More sharing options...
Bennett131 Posted January 2, 2016 Report Share Posted January 2, 2016 Craftsman, mac, snap on I've had good luck with all of them. The harbor freight one I used gave me fucky readings that's why I asked. Quote Link to comment Share on other sites More sharing options...
Bennett131 Posted January 2, 2016 Report Share Posted January 2, 2016 I have been using a craftsman for years. Works perfect. This one? Quote Link to comment Share on other sites More sharing options...
buddhabanshee Posted January 2, 2016 Author Report Share Posted January 2, 2016 The motor was warm..at least for the 1st cylinder for sure...and had wide open throttle. Did the second cylinder twice making sure everything was tight and still got the same reading Sent from my SM-G900V using Tapatalk Quote Link to comment Share on other sites More sharing options...
hoppedupandcutdown Posted January 2, 2016 Report Share Posted January 2, 2016 ^^That Rule of thumb on compression tests is no more than a 10% variation. But try again, both cold. And keep a close eye on it in the future, cause you are under the 10%, but pushing it. Quote Link to comment Share on other sites More sharing options...
willaduncan Posted January 2, 2016 Report Share Posted January 2, 2016 Definitely no need to warm the engine for a compression test Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
buddhabanshee Posted January 2, 2016 Author Report Share Posted January 2, 2016 Leak down test it. See if you maybe a bad hgHow do I do a leak down test? Sent from my SM-G900V using Tapatalk Quote Link to comment Share on other sites More sharing options...
possum Posted January 2, 2016 Report Share Posted January 2, 2016 Ive ran a motor with 120 and 150 psi for a few more duning seasons like that. I wouldnt worry about 10% difference. Thats real world experience not technically by the book someone made up. Quote Link to comment Share on other sites More sharing options...
willaduncan Posted January 2, 2016 Report Share Posted January 2, 2016 How do I do a leak down test? Sent from my SM-G900V using Tapatalk Intake side looks like such and exhaust removed with exhaust plugged Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
n2otoofast4u Posted January 2, 2016 Report Share Posted January 2, 2016 Run it! Quote Link to comment Share on other sites More sharing options...
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