compression numbers

Is 98 psi decent compression for an s4 turbo motor?
What are the appropriate numbers?

Soso..

isn't it supposed to be like 120 or something? I don't know for sure but for some reason that number comes to mind

compression numbers also go down if the motor has been sitting for awhile or JUST been rebuilt.

its always a chance buying an unknown motor.

Did you test it warm or cold? You should test warm because that's really the most accurate.

what's important is to have even bounces (assuming you used a conventional tester with valve button depressed) ... Now, the psi reading you see when it's bouncing is not the actual compression a Mazda tester would get ... it's really low-balling the actual compression for each chamber.

To get a reading that's somewhat accurate and assuming the bounces are even, you now need to get an "accumulated" psi reading on the dial (to do this, you don't depress the valve button on the gauge ... same as for piston engine procedure) ... that's your compression.

Don't get too upset about you are getting because there a lot of factors involved: how hot the engine is, how thick the oil is, how fast the starter turns, etc.

see for more info:
http://www.geocities.com/huguesdc1/faqcompression.html

hugues-