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I recently purchased a 2008 40th Anniversary with 48,000 miles. Before purchasing I had the compression checked at a Mazda dealer. The results were Rotor 1:7.5, 7.4, 7.3 and Rotor 2: 7.4,7.3,7.4. The Mazda dealer said that the compression was good. I have had the car about a week and was looking through the paperwork and saw that the RPM that the test was performed at was 300rpm for both rotors. Looking at the maintenance chart the numbers appear to be below the minimum compression readings. The android app returns values as "out of spec" and the foxed.ca chart shows the lowest reading to be 7.11. (Alt:1350ft)
My question is: Does this compression check show a good engine or a failing one and if failing do these numbers qualify for an engine replacement from Mazda? (The ten years is up in March of 2016)
300RPM is really high unless a 2009+ RX-8 starter was installed at some point which is somewhat unlikely. I have never seen a S1 starter (either of them) crank to 300RPM.
Can you scan and post what's written in your paperwork?
Blank out your name and other stuff, just the results.
If the reported numbers are at 300rpm then they interpreted the result incorrectly leading you to make the wrong purchase decision. Definitely retest it soon.
FYI it's 8 years not 10, so... a lot riding on that number.
01-20-2016, 03:21 PM
