In2tuners

I Tested the compression on my car the other day with a comperssion tester form advance auto. and it was reading about 83 psi on both rotors. In the book I got it says to take it to a daler for an more accurate test but how dose everyone else test there own.

jefraney

The dealer has a special tester that records all 6 faces of the rotors digitally. You can get a good ball park by removing the valve in the compression tester and reading all 3 numbers as the engine turns over.

fc3sboy1

im lucky enuff to own a mazda rotary compression tester but what ya can do is use a normal compression tester but you need to remove the check valve from it so ya can get an accurate compression from all three points of compression on the rotor.



randy

rabius

does holding the release valve do the same thing as removing the schrader valve?

jefraney

No. Holding the release valve will just let the compression whoosh out instead of holding the compression so you can read it. You have to remove the valve so that all the compression can be read.

In2tuners

How do you remove it

jefraney

Normally, the valve is at the very end, kind of like a valve stem. They make a special tool that screws it out, but if you have a small pair of needle nose pliers, they will work.

Jedi

I dont care how crappy a tester you own. You are going to rebuild it if they were any sides were around that range

BigTurbo74

also make sure to follow the procedure descibed in the fsm. it gives you a chart to compare your compression numbers to, with cranking rpm, atmospheric pressure, and other things considered. and remember to keep the throttle wide open during test...

Nospig

A leak down tester will give a more accurate condition of engine.