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-   -   Failing Compression isn't the only test your engine needs to fail (https://www.rx8club.com/series-i-tech-garage-22/failing-compression-isnt-only-test-your-engine-needs-fail-194710/)

Bigbacon 04-06-2010 05:02 PM

you'd think havinga 10 second crank at the dealership would tell them more that your car is borked.

think I would have walked back in and said, get me MAzda CS on the phone and lets deal with getting this changed NOW.

Mattiji 04-06-2010 05:04 PM

Good luck man - here's my advice, get a second opinion and contact mazdacorp USA/Canada and call the investigation group of customer relation affairs, they might help u out - they did for me -

Jedi54 04-06-2010 05:07 PM

RIWWP: Here's the TSB. unfortunately they don't indicate on here what the minnimum baro / voltage requirement is: http://www.finishlineperformance.com...4-08-1924g.pdf


Here is a compression calculator to compensate for cranking rpm: click desktop http://virusakos.freevar.com/

Here's the Service Manual where you can see the compression: http://foxed.ca/rx7manual/2003mazdarx8/
- engine
- mechanical
- compression

RIWWP 04-06-2010 05:11 PM


Some customers may experience a lack of engine power and an low engine idle speed during high ambient temperatures.
Well, tomorrow will be 83 here. (Record temps after record rainfall after near record snowfall. I think God wants this state to go away, and I'm backing him up) I'll take it out at lunch, and if I vanish, you will know why.

RIWWP 04-06-2010 05:13 PM


B - TEST DRIVE
1. Perform test drive lasting at least 40 minutes following these guidelines:
• Drive vehicle on city streets at speeds below 45 MPH.
• Air conditioning and fan speed on max.
• Accelerate at very light throttle keeping shift points below 3000 RPM.
• After 20 minutes stop vehicle in a parking lot, M/T in neutral and A/T in drive for one minute, and monitor
engine RPM using the DATALOGGER PID.
• At the 40 minute mark, stop the vehicle in a parking lot, M/T in neutral and A/T in drive for one minute,
and monitor engine RPM using the DATALOGGER PID.
• Safely accelerate the vehicle at wide open throttle (M/T shift at 8000 RPM) to the legal speed limit.
No way he did that. Odometer was the same in and out.

Old Rotor 04-06-2010 05:29 PM

Do you feel the Cat was the cause of your failure?

RIWWP 04-06-2010 05:30 PM

I do. As of November, I had the best engine I could have asked for, above average in all respects.

Proving it...that's the hard part.

MazdaManiac 04-06-2010 05:43 PM

Actually, your BARO voltage indicates a manifold vacuum of about 12", which is a totally f-ed motor.
Mine (which has even lower compression than your motor), pulls about 14" of vacuum at an altitude of 1000 feet.
RI is at sea level, so altitude correction doesn't come into play.

Jedi54 04-06-2010 05:45 PM

MM: so what do you recommend?
try another dealer? Go back with results and try to convince them the motor is F-ed up and to consult the Tech Line?

MazdaManiac 04-06-2010 05:53 PM

Pshh. I'd just pull a nipple off of the lower intake manifold and go back.
It'll run like crap, the vacuum will be even lower and most (if not all) dealer techs are such dumbsh*ts that they won't even look for that.

Jedi54 04-06-2010 05:54 PM

:rofl:
brilliant.

RIWWP 04-06-2010 06:06 PM

Hrm. I am not sure how engine vacuum is generated, and how compression plays a role in it. I would presume, thinking about it, that as the interior volume expands, the low pressure is what is being measured, vs the compression during that phase. Makes sense, both phases of the combustion cycle getting measured. And 'vacuum' is just lower pressure, not actually a vacuum.

So I also imagine that compression scores and vacuum scores are roughly related, if not directly related.

If that is true, then is it possible he screwed up the measurement and obtained a too-high reading on the vacuum?

MazdaManiac 04-06-2010 06:17 PM


Originally Posted by RIWWP (Post 3509812)
I would presume, thinking about it, that as the interior volume expands, the low pressure is what is being measured, vs the compression during that phase. Makes sense, both phases of the combustion cycle getting measured.

Yes.


Originally Posted by RIWWP (Post 3509812)
And 'vacuum' is just lower pressure, not actually a vacuum.

Yes.


Originally Posted by RIWWP (Post 3509812)
So I also imagine that compression scores and vacuum scores are roughly related, if not directly related.

Yes.


Originally Posted by RIWWP (Post 3509812)
If that is true, then is it possible he screwed up the measurement and obtained a too-high reading on the vacuum?

Yes, but it appears he didn't screw up the test as much as failing results were not recognized as such.
Just looking at the voltage output you can see that no amount of correction factor is gonna make up for such a low vacuum reading.

E.M.S. 04-06-2010 07:11 PM

what dealer was it? just wondering if you asked Zelse to just give Tom at liberty a call. when i showed up there and droped Marc's name i think the guy wanted to blow me. he must have dated Marc's sister or something.

dmc27 04-06-2010 09:09 PM

That's pretty pathetic. Hopefully you get better answers from a better dealership.

Marklar 04-06-2010 10:53 PM

That's bad news, I'm beginning to wonder if the engine warranty will still be worth anything if/when I actually need it. Mazda seems to be looking for ways to avoid honoring it.

WTBRotary! 04-06-2010 11:10 PM

Sorry to hear this man, sucks... hopefully this thing gets situated...

RIWWP 04-07-2010 08:29 AM

Update:

I spoke with Liberty Mazda, and he took down the test results, put me on hold for about 30 seconds, then came back: "well, those readings are consistent with a failed engine. In fact, those are the lowest readings I have ever seen."

I am dropping my 8 off up there (90 minutes away, or I would have gone there first, always requires a weekend appointment for me) tonight or tomorrow, and he will get to it as soon as possible. He said the last warranty replacement that they did had 6.1s across the board, and they still got it approved without issue.

He also said that the last engine replacement was tested on a tuesday, got an approval on Friday, and had the new engine in, tested, and back to the customer on the following thursday.

He also said that the BARO voltage doesn't have a set failing point, as it can vary from altitude and temperature, but there are no conditions possible that anything under a 5 will ever pass.

So this is less a "Mazda trying to avoid the claim" as it is a "dealer tech doesn't know how to test properly."

dmc27 04-07-2010 08:57 AM

Great news.

Now we know for sure not to bother with Tasca. Nothing but morons . . .


You should probably edit this into your first post so the Mazda hate doesn't go through the roof around here.


oh, and for no reason

:mchase: :mchase: :mchase: :mchase: :mchase: :mchase: :mchase: :mchase: :mchase: :mchase:

RIWWP 04-07-2010 08:57 AM

Yeah, good point.

CTrx8 04-07-2010 09:10 AM

good to hear. sad that the average joe would have been hosed here and wouldn't even know to fight or what to fight for but glad you were able to go in there with the right info.

MazdaManiac 04-07-2010 10:15 AM


Originally Posted by RIWWP (Post 3510463)
He also said that the BARO voltage doesn't have a set failing point, as it can vary from altitude and temperature,


Originally Posted by MazdaManiac (Post 3509785)
RI is at sea level, so altitude correction doesn't come into play.

;)...

RIWWP 04-07-2010 10:18 AM

Yup, just confirmation of what you said.

fyrstormer 04-07-2010 11:03 AM

Wow, ain't that some shit.

Let's see...if the compression is bad but the vacuum is good, what would cause that? I guess it could mean the seals are giving way under compression but they're not scored badly enough to leak under vacuum yet. Or it could mean only the hot side of the rotor housing is scored, which I suppose could happen if you've been using cheap oil for the life of the engine, and it's been burning off too quickly and not keeping the hot side lubricated well enough. I dunno, I'm just thinking out loud. But if you're just barely above spec on vacuum and way below spec on compression, well, then the guy's right, it won't be much longer before you get a new engine. Just don't do anything stupid in the next month, it would suck to get the warranty voided on a technicality.

RIWWP 04-07-2010 11:09 AM


Originally Posted by fyrstormer (Post 3510715)
Wow, ain't that some shit.

Let's see...if the compression is bad but the vacuum is good, what would cause that? I guess it could mean the seals are giving way under compression but they're not scored badly enough to leak under vacuum yet. Or it could mean only the hot side of the rotor housing is scored, which I suppose could happen if you've been using cheap oil for the life of the engine, and it's been burning off too quickly and not keeping the hot side lubricated well enough. I dunno, I'm just thinking out loud. But if you're just barely above spec on vacuum and way below spec on compression, well, then the guy's right, it won't be much longer before you get a new engine. Just don't do anything stupid in the next month, it would suck to get the warranty voided on a technicality.

Re-read the update please.

Vacuum result was still a failure, not above spec. Spec changes based on altitude and temperature (air density), but there aren't naturally occurring conditions that anything under a 5v reading would be a passing grade. Dealer was just lazy.


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