4/7/2010: SEE BOTTOM OF THIS POST FOR AN UPDATE

So might as well start from the beginning here. The B@Wers know the deal mostly, but with this experience, others should know what all happened, and the final result.

2005, 6sp manual, 56,439 miles.
First sold September 2006, traded in Oct 2007, I purchased with 8,400 miles Oct 27th 2007.

Up through November 2009, I have an incredibly healthy engine. I could get 24+mpg any time I wanted, power was flawless, smooth, everything you could want from a stock NA RX-8.

Then my cat started failing in December 2009. Clogged up. In the process of diagnosing, I replaced the coils, wires, plugs, air filter, reset the e-shaft sensor, fuel trims, cleaned the MAF. Found out it was the Cat, had it replaced under warranty. Took till the end of January for the dealer to get a replacement Cat in, had a borrowed BHR prototype midpipe on in the interim, courtesy of Zelse (awesome pipe BTW)

Cat replaced, but my 8 just didn't go back to normal. My mileage was back to where it should be for a few weeks, then started dropping slowly. Power starting to disappear. Misfires still happened regularly. I am thinking it's an O2 sensor, but before I get a chance to order a replacement, I start hearing a metallic rattling sound. Like a wrench left loose in the engine bay getting tossed around by the belts. Or apex seal hitting the housing. Or a piece of an apex seal getting bounced around in my header. Not constant, but definitely there. Power keeps dropping more. I realize that rev-matched downshifts aren't slowing me down like they used to, and I am having to use more and more brake. Then my starting times when warm and cold start increasing. Last thursday I can't get my 8 started on the first 2 tries after filling up on gas. So I make an appointment to get my compression checked, everything is pointing at failed compression.

The appointment was this morning. 6:45am to 2:00pm 7 hours I was there.

The advisor pulls the tech out right off the bat to hear the list of issues and my reasoning that it is failing compression. The tech is skeptical about the failed cat "he only ever knew of 2 cats to fail on 8s before" (he brand new?) Then he says he can check to see if "a special TSB was done",
with my response being "you mean MSP-16?"
He looks at me odd, wondering how I knew that, and says "yeah, that. Well, if the compression readings were fine when it was done, I don't know what else it could be." (seriously? cause compression never changes on these cars?)
He continued with "well, it's possible they never did it correctly, and didn't reset the shaft sensor, and that could be your problems",
to which I replied, "oh it's been reset 3 times since the middle of December".
He shook his head, "no, it has to be reset a special procedure in the manual"
"you mean the 20-brake pedal stomp?"
He rolled his eyes at that, and nodded, "yeah, that. Well, I'll pull the code and see if MSP16 was ever done, and go from there."


So whatever. I hand over the keys and let him go jack off for an hour. Literally. An hour later my 8 is pulled from the service parking and shows up in the service bay. For being the first one in line that morning with a scheduled appointment at 7.

8:30 rolls around, and he comes back, "well, I'm going to do both the hard-start diagnosis and the power loss diagnosis, and the MSP16 flash. I can't find a record of it being done, it will all be covered under warranty." (I swear it was done before)

9:30 rolls around, "well, the first compression test came back lower than I would like to see, so I am going to do the decarb and run it again, and if it's verified, we will get you a new engine. You will be here at least another 2 hours"

I ask him for the numbers, and he says "they were all 5.2s"

Ok, whatever it takes. I'm thinking it would take a hell of a magical decarb to increase my compression ~20% to meet the 6.X standard. Motor on the way. The tech did laugh a bit, saying that they pulled the freezeframe data from the misfire CEL, and saw that it was at 8,4xx RPM, "at least you drive it the way you are supposed to. Too many people don't". Warm fuzzy feeling. I got the tech on my side.

1:30. 3 hours later. He comes back. Well, the numbers went up a bit from the decarb, but when I put the numbers all into the computer, the result that it came back with was "no engine replacement needed"

WTF?

So I question him about a bunch of it, he is talking to me like an equal at this point, finally recognizing that I know what in the hell I'm talking about. He says that the compression is below spec, but the engine vacuum is above spec, and they both need to be below spec.

Engine vacuum? Is that another term for compression?

I ask him how far above spec it was, and he said "barely", so tell him, ok, I'll be back in a month or so to run it again. He said, yeah, I probably would fail then.

So, me, more than a bit irritated, figure they will charge me for all of this, since it isn't under warranty, only for me to have to repeat it when my compression fails enough that my vacuum also fails. At the counter, I pleasantly find out that I will not be charged for my 7 hours, or the work done. I ask for all the documentation for my records, and this is what they hand me.

I don't know how else to say it, so take a look at the compression readings yourself:


Yes. You see that right. PM me with an email address if you want to see all the documentation in a PDF (too large to attach)

And that "engine vacuum voltage" BS?



I have never before seen anyone post up compression results under a 5. I have two in the 4's
Note that on the right, he even notes the minimum spec of 6.9. My BEST rotor face is 23.2% below minimum spec. My WORST rotor face is 30.5% below minimum spec.

And note that the compression test in the 2nd test went down after decarb, not up. On all 6 rotor faces. And this had to have all happened since early December (I think the clogged cat overstressed the seals, not being able to evacuate the exhaust)

I did find out just after that, that the tech that was performing all of this WASN'T the tech I had been talking to. He didn't look special, but I guess he was a "manager". I was told that I have a motor mount that should be replaced, and a spark plug wire had a bit of rust inside one connector, and that the rattle was probably the "intake valve" (I think he means SSV?)



So anyway, apparently Mazda is looking for 2 metrics, and this bad of a compression isn't even enough to warrant a warranty replacement yet. Although the dealer didn't even send the warranty claim in for MNAO to deny it. They just deemed it not needed right there at the dealer. Not refusing a warranty claim. Saying that it wasn't bad enough to replace.

I am "shopping" the results around to a few other dealers, to see if any of them are willing to recognize that...as RotaryAmuse so precised put it: "your engine is Effed, and you need a new one"


UPDATE:
This is apparently mostly a dealer specific issue apparently. All my readings are failing, another dealer is going to take care of the engine replacement. This dealership was simply too lazy.

UPDATE 2:
The 2nd dealer did another compression test, and the engine passed. The engine didn't fail another compression test till 96,000 miles, and the engine was replaced at that time.

 

I had a friend who took his RX8 in recently and I noticed the Service Bulletin now states they need compression and vaccuum tests before MNAO will authorize a replacement.
Let me see if I can find the minnimums and we'll compare.

 

Yeah, rather than fighting owners after a failure is acknowledged, they simply don't acknowledge it in the first place. Saves lots of legal headache.

 

Holy crap!!

 

Damn!
But isnt the minimum spec 6.9 @ 250rpm?

 

awesomeness....

you think its so they don't have to deal with Mazda or because Mazda is changing the engine replacement specs so they don't have to do it so often?

 

Yes, it is. He even wrote it on the paper. They are passing it for a 2nd measurement. The new "engine vacuum"

The dealer makes a profit on an engine replacement, regardless of who pays for it. They just don't want to eat the cost if the warranty claim is denied by Mazda. Mazda Corp is likely just putting another block in to reduce warranty claims.

 

I think my last compression check came in 7.1, 7.1 and 6.8. There percentage difference was not great enough to be considered failing.

 

dam sad to hear

 

That is f'd up .

The fact that he said the compression went up after the decarb but the hand written results indicate it went down makes me wonder if he just didn't mix the results up ....

 

I attribute that to the fact that he wasn't the one doing the work. Lost in translation and all.

 

Don't forget, those compression numbers must be normalized to an engine cranking speed of 250 rpm in order to compare them with the Mazda spec. Since the rpm was 194-198, the normalized numbers would be quite a bit higher than those indicated readings and possibly within the minimum spec. You can find an rpm correction graph in the factory service manual.

 

Got a copy I can look up? Or care to post a screen shot of said graph? I believe you, but would like to take a look.

 

This **** is getting crazy. I would love to know the real numbers on engine replacements. it must be really high because they are getting harder and harder on replacing them.

He is right about the graph though, let me look at it.

On my first engine they told me in like an hour that I needed a new engine, paid for the rental, never told me **** about coils or plugs, and did not ask for any service records.

On my second engine (third in the car) they took a couple of days to tell me it needed to be replaced, did not cover the rental, and said I had to replace the coils and plugs before the new engine would be approved. I also had to provide oil change receipts. luckily I had and extended bumper to bumper warranty so I didn't pay for the rental or coil, etc. out of pocket.

But, I told the service guy that had I not had the extended warranty I would have raised hell like he had never seen before.

Here you go.

 

this makes me kinda scared that if my engine starts to die sometime before 100,000 or 8 years that I'm pretty much screwed. I think I am just going to start preparing myself for that idea now. Either that or if it messed up and is really close, i'll just drive the hell out it all the time in the hope it messes up more...

kind of dis-concerning for all of us if you ask me. All RX-8 owners should be worried about this now. Engine is still dying in your case but it's just not dead enough which mean your car isn't 100% of what it could be....

 

Yup.

If Mazda is waiting for the engine to fail so far that I can't drive it, well, I guess that is what I will have to do.



And if this screws with my planned trip to SevenStock this year, I will be royally pissed.

 

Your best bet would be to drive like a nanny if that's what you want to do ....

 

RIWWP: +1 w/GO48

there is a chart that Jedi was showing me that you can normalize the numbers yourself considering that it's damn near impossible to crank at exactly 250rpm. He was showing me the website when we tested a members car prior to the dyno day. PM Jedi...

 

RIWWP : is it starting any better after the decarb ?

 

Well, with numbers like these, driving the hell out of it isn't much faster than the nannys

I'm checking with a few other dealers, looking for a second opinion. Hopefully one comes through

Nope. Took ~10 seconds of cranking to start in the parking lot of the dealership when leaving.

 

Ripped from another thread, but the way I read it, at ~200rpm, anything below 5.5 is below minimum.

 

wow .. time to get a lawyer

 

Here's a graph I developed from the factory service manual. It shows the minimum and "standard" lines. Ignore the data plotted on the graph 'cause it is not relevant to your situation. You will have to extrapolate the position of your actual readings since they are off the lower left of the graph. Draw lines parallel to the min and std lines to see where your numbers are relative to 250 rpm. Just eyeballing it, it looks like your numbers will fall very close to the minimum line.

 

At 200 (196, 198), it looks like the minimum is ~5.7

I still fail. Badly.

 

Nope. Mazda isn't refusing to back their warranty. They are saying that a warranty isn't needed in the first place. Perfectly legal. I went through an engine rebuild warranty legal fight with Toyota in 2004. I know the laws around it quite well. This is a perfectly legal way of reducing warranty claims.

Still far below from what I see.

Cause someone should quote that.