Energyblue98 Posted February 10, 2014 Share Posted February 10, 2014 What are good numbers to look for on a compression test? over 150psi on all 4 cylinders? What about leak down test numbers? at what point should I be worried? Link to comment Share on other sites More sharing options...
discojon Posted February 10, 2014 Share Posted February 10, 2014 We need to know what car you are looking at first. Link to comment Share on other sites More sharing options...
Energyblue98 Posted February 10, 2014 Author Share Posted February 10, 2014 08 lgt spec b Link to comment Share on other sites More sharing options...
Moderators BarManBean Posted February 10, 2014 Moderators Share Posted February 10, 2014 150 on all four would be great (honestly I wouldn't expect that--more likely to see 125-145). You should worry if you find a large difference between 1 or more cylinders. If they are all within 1-3psi that's a good thing. Good results: 133/135/133/134 Bad results: 145/144/145/80 "Bullet-proof" your OEM TMIC! <<Buy your kit here>> Not currently in stock Link to comment Share on other sites More sharing options...
Energyblue98 Posted February 15, 2014 Author Share Posted February 15, 2014 120 on all four. Good results? Link to comment Share on other sites More sharing options...
mwiener2 Posted February 15, 2014 Share Posted February 15, 2014 good enough My Mods List (Updated 8/22/17) 2005 Outback FMT Running on Electrons Link to comment Share on other sites More sharing options...
Energyblue98 Posted February 15, 2014 Author Share Posted February 15, 2014 That's not too low? Link to comment Share on other sites More sharing options...
Moderators BarManBean Posted February 15, 2014 Moderators Share Posted February 15, 2014 If every cylinder was at 119-121 it's probably a pretty healthy motor. A different shop with a slightly different method might come back with 135 across the board. "Bullet-proof" your OEM TMIC! <<Buy your kit here>> Not currently in stock Link to comment Share on other sites More sharing options...
domoMKIV Posted February 20, 2014 Share Posted February 20, 2014 Another factor would be if the test was done on a cold motor (numbers a bit lower) or a warm motor. Link to comment Share on other sites More sharing options...
DrD123 Posted February 24, 2014 Share Posted February 24, 2014 Also at what elevation you are located - 120 psi measured say in Albuquerque, NM at 6000 feet above sea level would translate to about 144 psi at sea level (which is what the values in the manual are quoted at) Here's a table to correct (divide the pressure you measure at altitude by the correction factor to get the equivalent at sea level) Altitude Factor 1000 .9711 2000 .9428 3000 .9151 4000 .8881 5000 .8617 6000 .8359 7000 .8106 8000 .7860 Anyway - as already pointed out, consistency is key - if you only see a couple psi variation cylinder to cylinder, you are probably fine (within reason - if they are all the same, and say 80psi or less, you might have a problem) Link to comment Share on other sites More sharing options...
PtPixel Posted February 24, 2014 Share Posted February 24, 2014 I'm at sea level and my pre-purchase compression test returned 120psi on all four cylinders, so yes they're fine numbers. Link to comment Share on other sites More sharing options...
Energyblue98 Posted February 24, 2014 Author Share Posted February 24, 2014 Yes mine was around sea level. I bought the car. Runs great. Something squeaking in the rear but other than that it's not bad. Link to comment Share on other sites More sharing options...
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