Did a compression check on my car with a standard autozone checker. S4 Turbo with 169,000 on the OD. Both Trailing plugs were removed. And tested from the trailing.



Front rotor:



95 psi hot Throttle wide open

85psi hot Throttle closed



Rear rotor:



85 psi hot Throttle wide open

75 psi hot Throttle closed



As I understand it, mazda specs indicate that a variance between rotors of no more than 15psi is ok. What worries me is the 75psi closed



Any opinions?

Mazda says to crank with the throttle open. You're fine.

Boy, this looks familiar. https://www.nopistons.com/forums/pub...IR#>/smile.png





-Ted