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Failing Compression isn't the only test your engine needs to fail

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Old 04-07-2010, 11:10 AM
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i'm having some issues and i know when i finally move and have time to get this straightened out in the next 2 weeks, i'm going straight to liberty. i know i wont get **** for having LS2 coils because Marc has already straightened them out there or they atleast understand that we only replace what was mis engineered. i am having some heat related low power issues and i know i'm not going to get as big a headache by going to them.
Old 04-07-2010, 12:59 PM
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This video might be enlightening for someone else as well. Warm (hot actually) Cranking time for my 8 with the compression numbers posted.

http://www.youtube.com/watch?v=dBquXwwo0do
Old 04-07-2010, 01:35 PM
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Thanks for the updates!

Glad to hear that Mazda are still approving engine replacements for low compression results! I was ready to sell the car after the first few posts, but now I feel much better.
Old 04-08-2010, 01:19 AM
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I had a similar issue
I'd have to assume that their decarb procedure can't help THAT much, especially on an engine that I've seafoamed a few times, right?
https://www.rx8club.com/series-i-tech-garage-22/interpretation-compression-test-results-191568/

When the F did this vacuum test business start?
And has anyone in the NY area had a no-hastle engine replacement??? WHERE?!?!
Old 04-08-2010, 05:52 AM
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My numbers were lower after a decarb than before. Every single face was lower than pre-decarb. 1 day later, my idle was unstable by the time I got it to Liberty Mazda. I think mine is a rapidly accelerating failure, not a slow death lingering on.

It appears the vacuum test started in 2009 sometime, but it also looks like dealers have the option to flag the engine as passing at their discretion, since the original dealer passed my engine, a 2nd dealer failed it outright over the phone as the worst he's seen. I wouldn't be shocked at all if my compression results at Liberty are even lower than Tasca.

Of course, I am fairly sure the tech didn't do the road test at Tasca. By fairly sure, I mean I'm positive. My odometer didn't change and since I glanced at my 8 on the lift every few minutes for the 7 hours I was there, and the only time it wasn't on the lift was before any of the tests and after they gave it a passing score.
Old 04-08-2010, 08:34 AM
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Well, if the carbon was caked onto your seals, there's a good chance that they were providing some sealing effects. Once you seafoamed the car, all that carbon disappeared.
Old 04-08-2010, 08:52 AM
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Agreed.

First dealer just being lazy. I dropped my 8 off at Liberty last night, and the idle was all over the place when I pulled into the parking spot. ~1,300 to 500 and back, fluttering, not surging. I tried to get video of it, but it stopped before my phone's camera initialized (still did it for about 15-20 seconds) It would have failed the 45 minute road test if the mechanic had actually done it, and the vacuum test is only needed if it passes the road test. Of course, it actually failed the vacuum test too. They possibly rigged the computer to show a pass much lower than spec to avoid paperwork.

Or they manufactured the whole document.

I will be filing a complaint with MNAO against Tasca, and a praise to the sky for the other once I have my 8 back.
Old 04-08-2010, 11:31 AM
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so is Liberty going to do the whole diagnosis and we're hoping this tech isn't a lazy bastard?
Old 04-08-2010, 11:40 AM
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Yes, I spoke with them about 20 minutes ago. They are going to run the tests today, more as verification of Tasca's results. When I dropped it off last night, I left a copy of all the documentation that I had from Tasca in the envelope with the key.

I also left them all my oil filters in a bag tied down in the trunk. He said that my MazdaUSA records and oil filters should be enough. The only other thing I have is credit card statements showing AdvanceAuto purchases.

(Which, of course, doesn't prove I bought oil, though oil purchase receipts don't prove I changed the oil, or that it was even for this car. Even if I had gotten my oil changed at a shop, their receipts don't really prove that oil was in fact put back in the engine, just that I was charged for it. Everything is just an assumption that the correct procedure was followed, all just circumstantial evidence pointing to correct maintenance of the car anyway.

And no court in the nation would uphold a requirement for warranty work that all service be done at a dealer when it was not previously stated. Unless you can find me 12 randomly picked people that disagree
)
Old 04-08-2010, 11:41 AM
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your car starts faster than mine. even after a new battery mine takes 5+ seconds to start. cold/warm doesnt matter.

it still runs 14s and traps above 95mph though...
Old 04-08-2010, 12:00 PM
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I guess my starter is healthier than yours then?
Old 04-08-2010, 02:11 PM
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So update, change of story again....

Not really bad news. I guess.

Liberty ran through a full range of testing, 2 compression tests, vacuum voltage test, 2 mechanics and the advisor each took it for road testing, and they can't find anything wrong with it. The compression tests they ran came up with 6.7s, 6.8s, and 6.9s, with a crank speed of 225rpm. They look for 250 crank speed, so he said if they could crank it up to 250, then I would have numbers in the low 7s easily. Still within spec.

Not sure what changed between the two visits other than competent techs vs terrible ones, but all 3 of them agree that my 8 still has more pep then they are used to seeing and feeling from 8s. They did comment on my clutch being way stiffer than they are used to seeing from 8s. He said they did everything they could to find a reason to fail the engine, but couldn't find anything. And I believe them.

I know I am down on power, and I am much more confident that these techs know what they are talking about, so I am willing to accept their results. I am not willing to accept my 8 as being normal though, because I know I am down on power, even if only to where I "should" be. I'm back to the 02 Sensor failing and/or the Secondary Shutter Valve (which might be the noise I am hearing). He did say that the SSV, which if it goes bad, is usually very inconsistent. I've got ~3,500 miles before my full powertrain warranty ends to rule in or out the SSV to avoid paying for that out of pocket.

So I will probably have my 8 on the trip to VA. Hopefully I will have something for datalogging by then to get this figured out.


He is only charging me their cost of the diagnosis, and not the full fee, and I am perfectly prepared to accept that.
Old 04-08-2010, 02:16 PM
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The compression numbers Liberty got were all 6.7s 6.8s, and 6.9s at 225 rpm, which puts me low 7s when normalized to 250rpm.

Maybe I am just reacting from feeling a drop from the 9s like I have been used to down to the 7s where other 8s are?

Dunno









I should probably get the title of the thread changed.
Old 04-08-2010, 02:22 PM
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Wow . . . Tasca is completely incompetent, I guess.


The one thing that may be involved with the terrible idle and such after Tasca had it would be the reflash. Ask Libery what they see in the records since you know they are competent and honest. If the MSP 16 was never done until Tasca, you may have the erratic idle that many reported experiencing after that flash.


Not that it clears up the low power issue and hard start prior to Tasca's reflashing, but it could explain some of the stuff last night / today.
Old 04-08-2010, 02:26 PM
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Agreed, it could explain some of it.

And maybe the rest is just that I have gone from the 9s to the 7s in the past 2.5 months and my buttometer picked it up. He said my starter is cranking low, so replacing the starter might help the starting problems...but.

Signing up for autox sunday, long drive to VA, lets see what happens.
Old 04-08-2010, 02:43 PM
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Originally Posted by elysium19
When the F did this vacuum test business start?
!
2008. its an easier test to "normalize" and get good results from techs in the field than the compression test.
Old 04-08-2010, 02:51 PM
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Originally Posted by RIWWP
but it also looks like dealers have the option to flag the engine as passing at their discretion, since the original dealer passed my engine, a 2nd dealer failed it outright over the phone as the worst he's seen.
Only a QMD dealer could pass or fail on their own and even then Mazda is going to want to see the baro test results at some point.
interesting that you got the number from the first dealer at all. they weren't sharing them originally.

what was the baro number at the 2nd dealer?
Old 04-08-2010, 02:54 PM
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I don't have the numbers from the 2nd dealer yet. I will be asking for them when I pick up the 8 Saturday.
Old 04-09-2010, 08:54 PM
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I've had a dealership refuse to do warranty work on stuff that was clearly covered under my warranty, when they sent the info to the head offices, they were very deceptive in how they describe the problem, and recommending it's not covered... and once its denied, mazda wont listen to anything.
Old 05-01-2010, 01:50 PM
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my 04 only gets like 16 or 18mpg. and when idling, the car just kind of shakes vibrates. like u can see the middle of my steering wheel and my stickshift shake actually. do these symptons sound like something torwards failed or low compression, and give me a case of getting it tested and hopefully a new engine? i am asking cause ive only had this car for a few months now, so im still learning stuff. would really appreciate a reply :D
Old 05-01-2010, 05:41 PM
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If you think you're having a problem take it in. Your gas mileage sounds normal and the vibration at idle concerning your shifter also sounds normal. Someone will chime in if they have a different opinion than mine.
Old 05-01-2010, 08:49 PM
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BUNCH OF n00bS ! SEARCH !

Vacuum/BARO test is not new.

IT has been in since the 4260f Recall (the first ECU reflash recall), Mazda even "sell" a tool to test the BARO/Voltage. I have that Tool(which was like what 25 bux I think?)and I know how to use it (by now)

Anyway, your engine is still ok for now ... in ur opinion, is that a good thing or bad thing lol ?
Old 09-12-2012, 12:07 AM
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Long time thread revival!!

RIWWP. When the CAT failed did you get a CEL? I know the ECU monitors the front and rear O2 sensors to make sure the CAT is running efficiently, so I am wondering if a plugged CAT is something the ECU can pick up.

Also, in the end of this thread, do we still believe that a failed CAT can kill an engine?
Old 09-12-2012, 08:18 AM
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I got misfire CELs only. No cat failure CELs.

The failed cat cooked my front o2 senskr, and no codes for it but replacing it clearly made a difference in how my 8 was running afterwards.

And yes, I still believe that my engine was damaged from that cat failure. I had several unexplained issues that persisted from that point until my engine finally failed the compression test 40,000 miles later.

I had:
- 'burps' in the power that were entirely random, more noticeable than a misfire, never threw a misfire code. Like I got off the gas for ~1/2 a sec. Never solved through ignition replacement
- on cold startup, if I didn't let it idle warm i'd get a dense cloud of smoke from the tail pipes at exactly the same time every time (same stop sign down the street from my house). No one ever able to suggest a theory as to why that couldnt be disproved.
- slow power loss
- roughened power delivery

All fixed with the reman at 96k, all started within a month after that cat failure
Old 09-13-2012, 06:35 AM
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So the engine was eventually replaced 40k miles after the second dealership gave you the high score?

So the cat can be a silent bomb...that's annoying. But 40k is almost like half of the life of a rotary engine anyway. :P

I guess we just gotta keep the cat on the mind...and those misfires probably accelerate the cat failure I guess.


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