Compression numbers...odd..

[Infiltrate2000]

Did compression test on 98gsx. getting about 135psi across all over after 8-9 cranks. Weird thing is i keep cranking, the compression will go up to about 180psi and then stop. I was always told to do test with 8 cranks.
My question is, any reason why the number is going up with more cranks, especially reaching 180? I seen cars with bad motor, and the compression almost never reached such a high number no matter how many times you crank.

 

[MichaelSuch]

When I did mine it was 160-170 all across cranking about 3-4 times. Was your motor rebuilt? High compression pistons have a little to do with it I believe.

 

[Kash]

Did you do this on a warm or a cold motor?

 

[DSMRoadrash]

bad ring end gap ?

 

[Boost92awd]

Did compression test on 98gsx. getting about 135psi across all over after 8-9 cranks. Weird thing is i keep cranking, the compression will go up to about 180psi and then stop. I was always told to do test with 8 cranks.
My question is, any reason why the number is going up with more cranks, especially reaching 180? I seen cars with bad motor, and the compression almost never reached such a high number no matter how many times you crank.

You should only be cranking it over 3-4 times. It will go higher with more cranks because the cylinder is just building more and more pressure. Do it again and this time only crank it over 3-4 times.