I tested my compression today and I am at 190, the car has 100,000 miles on it. I also wanted to know how much our cars had from the factory and if thats right for the amount of miles on my car. Thanks

 

thats what mine blow, how many pumps (cycles) did you let go when you got your reading, 3,5,7... just woundering. mine was at 3 cycles, at 165 psi and 5 about 180-190 psi and 7 was up around 200-210 psi.

 

I dont remember exactly how many times but it was around 5 or 6 and this was the #1 cilinder

 

I believe the numbers will read low if you don't prop the TB blades open while cranking. It's more informative to get the reading on all 8 cylinders so you can see the variation between cylinders. I realize that's a lot more work but numbers off one cylinder could be misleading.

 

Yeah what you want to do is test all and look for consistency more than anything else, and yes prop the TB open.

 

if theres more than a 20% differnce between any 2 cylinders you have issues,

 

I did hold the throttle open and I know I should check all of them but I wanted to know if the number I got is good or not and what it is from the factory.

 

190 is OK but that is also asuming the gauge is accurate hence the insistance that consistency is the key over just numbers. I get 195-200psi out of my 180K LT1 in my wagon but that has a little different cam which will affect readings some.