Eldragon0

So... guys/gals.... I seem to be having an issue with compression test results and Mazda. I'm asking for a call to arms. So far I've talked to 4 rotary mechanics at 4 different Mazda dealerships. Two say anything lower than 7 IS BAD, and they wouldn't personally consider anything under 8 ( Or high 7's). The other two said low to high 6's are normal and fine. They wouldn't touch anything under 5. and 4 is replace time. I clarified these numbers were indeed at 250 rpm's and they all stuck by those numbers. I have a car I want ( yes another one XD) but I will only buy it if I can prove to the dealership that 6 IS BAD. So please contact your favorite mechanics for me, and get their opinions on compression numbers.

9krpmrx8

iTrader: (46)

Well, the problem is that a couple of compression charts have been released over the years and there are circumstances where one engine would be considered passing on one chart but failing on another. And the number means nothing without knowing the altitude,engine RPM, etc. So if they are giving you an answer without knowing all that then they are typical dealer mechanics.

I also doubt four dealers had "rotary mechanics". Dealers are not even allowed to pull apart a Renesis and generally most dealer techs are untrained.

Eldragon0

Sorry for the misleading information Mr./Miss Lots of posts :P. The amount of dealers I've called is closer to 20. Those are the four that said "yes here's our rotary specialist" Are the one's I got their numbers from. I'm interested in How much of a fault is allowed. The mechanic who did this particular test said he rain it 3 times and the numbers he got ranged from 6.2-6.4. I've done all the reading I can and I don't think I've found a single place that says those numbers are ok at 250 rpm's.

9krpmrx8

iTrader: (46)

Conspiracy ended. Time for a new engine. Your elevation will affect the results but that is failing on most any chart and on the android app and on the online calculators.

RIWWP

iTrader: (2)

Eld,

9k's reference about the multiple charts and conditions is correct. It creates confusion where there shouldn't be any, and this confusion isn't magically clear when you start talking to dealers. Some dealers won't diagnose a failing engine till you hit normalized 5.9, others have deemed engines as failed at a normalized 6.9. There is no real way to "Clear the air". If you talk to a dealer that adamantly believes that you have failing scores, then it's pretty clear that you should be choosing that dealer to get your test done at


For reference...


This is the chart that is in the official Mazda dealer shop manual for the series 1 RX-8, as it exists on the US Mazda dealer network right now (i can confirm that through my job). This chart says you haven't failed yet.



This is the chart for series 2 RX-8s in the shop manual. Unknown why they have a different chart, one that would generate more warranty claims? This chart has you failing


This chart was given to one of our admins by someone within Mazda dealing with engine failures. This one is in theory an "optimum" chart, as the line is really high. Would mean that most engines are DOA from the reman facility if that was a failing line.


This chart was given to the same admin by Mazda Canada. Assuming the B line means failing (just an assumption, I don't have any legend for it), you would be failing. It does appear to be the same chart as for the series2



If you REALLY want to generate confusion at a dealer, bring them all 4 charts You will be lucky to get out of there without them thinking you are scamming them.

Eldragon0

Thanks :D I had found two of those chart. Now I need to figure out if I can convince the dealership to get a second opinion. stupid dealership just trying to steal my money. But it looks like they have taken down the life time power-train warranty on it. So it may no longer be worth it unless I can convince them to put a new engine in before I buy it.

RIWWP

iTrader: (2)

So they find out, at your request, that the engine is close to being dead, so they pull the powertrain warranty off of it because it's a known losing deal. Sounds about right.

I would honestly not bother pursuing it that much. The dealer won't complain about losing your sale, since they can find someone else that isn't going to check the compression first, and can get more money out of them because of that.