charkra

Hello all, looks a great forum here, I have been trolling for the past few weeks and decided to purchase a 2005 RX8 18,700 miles on the clock.

As recommended,I took the 8 to the dealer and had the 4206F update, and also a compression test. They came back and said that the compression was borderline Low, and asked if they could perform a decarb procedure. The performed the decarb (took about 90 mins) and then they ran the compression tests again, and these were the results:
Rotor 1 - 8.2, 8.0, 8.1 - Rotor 2 - 8.1, 7.8, 8.0

I do not know what these results indicate, but whilst talking with the tech he mentioned that there was a lot of carbon build up - and the plugs were also carboned up too, indicating that the car was probably not driven too hard in the past. He also mentioned that the engine mounts had grown stiff and could probably be replaced to help with idle being smoother (I had indicated that the idle was a tad rough occassionally).

Can anyone interpret the compression results - do they sound like they are where they should be - I will continue searching the forums for other answers in the meantime.

Thanks

dannobre

iTrader: (3)

Depending on the RPM those results aren't too bad ......

MazdaManiac

iTrader: (3)

In reality, those results are actually rather good, regardless of conditions.
Altitude is also a factor, in addition to RPM.
But unless those results were in Death Valley and at 500 RPM, they are acceptable.

charkra

Thanks for the responses - I did call the service dept back and ask what the RPM was , and their response was it was run on their standard rig, depends on voltage, yada,yada.... Unfortunately the guy who I called back to was not able to get hold of the rpm when it was run , but mentioned it would have run in their standard parameters for a RX-8. The guy who did the actual test is a current 8 owner, and as I mentioned I had just purchased it and was checking it out, I would sincerely hope he would have told me if it was bad, especially as he recommended the decarb procedure (which Mazda paid for ) which was great.

Pico

iTrader: (2)

As stated those numbers are alright
Also, the readings on all three sides of both rotors are relativity close to each other. Meaning your Apex seals are waring pretty evenly which is very important.

Read the stickies and enjoy the ride

rgarcia9

Since I saw Jeff review Charkra's compression numbers I figured I should test my luck and see if he could do the same for me.

I posted the test results on my local forums but just figured I would get a bit more feedback here.

I just want to make sure my renesis is in shape before purchasing a COBB AP and Tuning from MM.

I was told by my locals to sea foam, so I have been reading DIY's and will definitely have time to get around to it this weekend.

Thanks fellas!

Heres the link:
2005 RX-8 6 Speed July 2011 49,000 miles

MazdaManiac

iTrader: (3)

Looks fine to me!