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Compression info please

  #1  
Old 07-05-2009, 07:53 PM
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Default Compression info please

Today a friend and I were working on a car that we presumed had bent valves so we got a compression tester. The car we were testing read about 30 psi on all cylinders so just to make sure the guage was accurate we decided to try it on a normal working vehicle (my civic). My readings (from drivers side to passenger) were 85/95/95/100. This seems really low. My engine has about 255K miles on it but other than that appears healthy (no leaks, no cel, no rough idle). Does this sound accurate?
 
  #2  
Old 07-15-2009, 11:35 AM
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im not 100% wut the compression should be but in my crx i tested throm driver side to pass it was 60/120/120/110 and i have 245k on it so there might be somthing wrong with prolly both of ours...lol dont know if this helps you...
 
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Old 07-15-2009, 11:37 AM
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Originally Posted by candyman420 View Post
im not 100% wut the compression should be but in my crx i tested throm driver side to pass it was 60/120/120/110 and i have 245k on it so there might be somthing wrong with prolly both of ours...lol dont know if this helps you...
Cyl 1 is nearly dead.
 
  #4  
Old 07-15-2009, 11:39 AM
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Candyman, you have definite problems. Cylinder 4 is reading way too low; the rule of thumb is the highest and lowest cylinder readings should be within 10% of each other.

I don't know what the specs are for civics offhand, but even 100psi sounds pretty low. Usually cylinder compression readings should be in the 150-200psi range, depending on the engine.
 
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Old 07-15-2009, 11:45 AM
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Originally Posted by reaper2022 View Post
Cylinder 4 is reading way too low
Reaper -- Cylinder 1 (driver's side) read 60 PSI.
 
  #6  
Old 07-15-2009, 01:28 PM
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ok so ronj... that was on my crx before i did my mini me swap ....wuts the compression supost to be at then??
 
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Old 07-15-2009, 01:37 PM
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CRX: About 185 PSI (and a minimum of 135 PSI). Same for your 94 Civic.

These numbers assume that the test is done correctly.
 
  #8  
Old 07-15-2009, 01:43 PM
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they where done the best i can do by myself... 1 thing again i need ur timing diagram again.. if u didnt see my other thread??
 
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Old 07-15-2009, 01:45 PM
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Originally Posted by candyman420 View Post
...1 thing again i need ur timing diagram again.. if u didnt see my other thread??
What do you need? What thread?
 
  #10  
Old 07-15-2009, 01:48 PM
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my cam is 180deg off of the crank.. i need to know witch little line to line the crank pully up to on the plastic belt cover?? the single line or the 3 lil lines??
 

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