Blown Motor
 

Following in the traditions of its predecessors, my RX-8 has suffered premature engine failure due to lost compression. Car is dealer maintatined, oil changes at better than factory recommended intervals, no modifications. Engine started to fade in the 45K-48K miles range. Having been an RX-7 owner, I had my suspicions. Dealer, however, said there was no issue.

Condition remained and now at 58K the compression has dropped to the point (dealer nows confirms) that I am encountering starting problems. I had hoped that the redesign of the Renesis would eliminate this issue, unfortunately my hopes now appear to have been in vain.

Initial discussions with dealer and area Mazda area rep did not fare well regarding warranty coverage, looks like I'll have a battle on my hands.

Anyone else share on similar issues?
:wallbash:

Do you have a manual or auto? Also, can you post your build date, it is located on the sticker on the inside of your drivers door.

I hope you have some documentation on your earlier trip to the dealer showing your concerns at that time. Good luck.

I hate these threads. What are your compression numbers?

funny how people only find this forum after they blow an engine or have a major problem!!!!!

hmmm i wonder why that is. i know i was here 6 months before i got my car. i just spent a hour on a hybrid site trying to find 0w20 oil.

go figure.

beers

This stuff scares the crap out of me. Would some people with over 50k on their 8s please check in to this thread and tell me they are having no problems!

Blown Motor
 

Answers to questions from Brice:
1> Manual Transmission
2> Build Date June 2003

Answer to question from Go48:
Rotor#1 - Chamber 1 = 98.6, Chamber 2 = 99.035, Chamber 3 = 94.54
Rotor#2 - Chamber 1 = 102.66, Chamber 2 = 97.295, Chamber 3 = 101.79

General Note:
To anyone reading this thread, strongly suggest you get your motor compression tested, even if you have to pay for it, so you will have a baseline of comparison for the future. I wanted to do this when I first took delivery on my ride back in 09/03 but never got around to it - placed too much faith in the good press on the Renesis design.

What could possibly cause this? Carbon buildup? It doesn't sound like he has any other kind of trouble, just doesn't make sense that he would loose compression for no possible reason.

5/2003 build date 51,500 stills runs great :ylsuper:

my guess is a bad metering oil pump that did not get caught. i know mine didnt get repalced till 30k miles and it does cause me some concen.

my build date was 10/03

beers

Blown MOTOR
 

In my RX-7 days, there was a 'mystery' around premature engine failures too. Never heard a good reason, although the closest was minor deviations to primary machining specs during production would cause excessive wear and premature failure. With the movement of the ports in the Renesis design, some tech writers I read prior to buying my RX-8 noted that this change should improve engine life and reduce the occurences of premature wear/failure. I bought in to the logic of those statements.

I understand dealers who change out engines must immediately return the ENTIRE engine INTACT to Mazda to get credit on it (note: this is just 2nd hand info on my part). Hence the dealers are not allowed to do any diagnostic disaasembly and hence no validation of the causes for the 'mystery' failures.

are these the 'before' or 'after' readings?

Compression readings are based upon cranking rpms as a factor in the equation. Without these we don't truly know what we are looking at. If you can get these it would be really helpful to everyone.

Blown Motor
 

After (dealer diagnostics results).

Blown Motor
 

MAZMART:
I was not in the repair bay when the compression testing was done by the dealer, but I assume these were static numbers taken when cranking the engine over as it was not in running condition when the car was towed in and the dealer did change out the plugs (it was due, had 40K on the plugs and saw 2 samples afterward that the dealer showed me that were worn & needed replacing).

He means the cranking RPM. There is a chart in the service manual that shows what the compression should be as a function of cranking RPM. The faster the starter turns the engine, the higher the compression reading should be.

MadDog:
Sorry, but I don't have that info specifically. Best is that I assume they were cranking it at whatever the standard RPMs are that a starter is capable of generating on a cold engine start in a heated service bay with the car's battery in decent working order, a compression tester hook to one chamber/rotor combination, and the plugs out in all other chambers (complete guess on my part).

the numbers arent that bad are they? where's the chart-somebody post here. besides it seems to me we usually see rear rotor compression loss not front-odd i know.

Some dealers are sharp and some are clueless. Hopefully they realise the neeed for rpms in this test. The tech line folks probably asked them for this before authorizing a motor. See if they would be kind enough to provide you with these numbers. By the way, there was someone about a year ago who had 80,000 miles on theirs; travelling salesman or something.
Paul.

Blown Motor
 

To ZOOM's Note:
If someone can post the info on testing compression relative to cranking RPMs, etc. from the service manual on this thread I will use that info to try and get an explanation from the dealership on how they established the numbers that I provided earlier and put them up here. This would also give me a point of reference to use in deciding just how bad my results are relative to factory specs and how to proceed in seeking relief from Mazda for this problem.

Thanks!

Here you go.

From what all I have read on this forum the average cranking speed is between 200 and 250rpms, so if you are seeing numbers lower than 100, either your car was cranking very slowly or you really do have bad compression in that rotor housing.

Blown Motor
 

MadDog - thanks for the chart!

I checked with the tech at my originating dealer that tested out the compression numbers provided earlier in this thread. He was cranking at 250-270 RPMs which should yield numbers in the 130 range based on the chart. Numbers I got on my rotor pairs were obviously below this by a wide margin across all chambers and hence his decree of a DOA status on my motor.

I am now in negotiation with Regional Mazda Rep and my dealer about coverage for the replacement. By my records I am able to document that my first claim regarding power loss occurred between 47K & 52K on the factory motor (which the dealer did not choose to investigate - remedy was to drop some injector cleaner in the tank, their part code on same being BG208 44K). I am being offered a 50/50 deal to replace with a reman motor and a 12/12 warranty on the reman unit. Rather than a long and drawn out fight over whether I should get full warranty coverage on the failure I am leaning toward paying the 50/50 but with inclusion of an extended 36K warranty from either Mazda or a reputable 3rd party with a policy that is not loaded with exceptions and escape clauses. A 12K based waranty does nothing for me given the possibility that the reman unit may prematurely expire under the same scenario as the factory motor did.

Does this arrangement disagree in any major way with what others have worked out with Mazda for engine replacements? Does anyone have experience, good or bad, with a 3rd party firm offering extended warranties on rotary engines?

i think the 50/50 with 12k (not 12months) is pretty decent

Your engine was dying at 44K miles so Mazda is responsible, under their warranty, to replace it. If you're willing to shell out at least $1,500 for your part of the replacement, go for it. Personally, I would hold their feet to the fire until they came through with an engine replacement at their cost. THE ENGINE DIED WHILE IT WAS UNDER A FULL WARRANTY.

i agree totally, the symptoms were already documented. this is mazdas problem. stick to your guns.

beers

I hate to drag this out but, could you elaborate on what you mean by 'Engine started to fade'? Was it an increase in starting difficulties, cutting off occasionally with the AC on when brought to a stop or was it a performance issue (Lack of proper acceleration)?

Blown Motor
 

My initial indication that there was a problem was Purely Performance related under normal driving conditions, and obviously a "soft" factor relative to identifying an issue exists and then getting support from the dealer for the problem (or now debating warranty coverage for same). I "felt" the change in performance in acceleration and general driveability. Without having established metrics of baseline performance, (for instance compression figures early in the life of the motor, dyno numbers, or similar) it comes down to the perceptions of the individual owner/driver and the ability to pick up on an issue like this under normal driving conditions. There was no definitive warning of the issue via registering a CEL event or similar, and hence I did not get much attention from the dealer when I first reported the problem. They had no definitive break/fix event to tie my complaint to.

It was only when the vehicle would not start, and the dealer could not attribute the condition to flooding or other, that a break/fix issue was evoked and further diagnostics took place. That is the basis of my claim for warranty coverage for this motor replacement. This motor obviously took a while to fail, the warning systems on the car provided no way for the owner to be made aware of same, I did notify the dealer of the condition toward the end of the warranty period but dianosis of the root cause was not preformed then, subsequent break/fix event shortly after exceeding maximum warranty mileage confirmed retrospectively my earlier noted issue and hence my right to coverage under warranty for thie required motor replacement.

I'm sorry, but there is no way i would settle for a 50/50 replacement on an engine it 58k miles. Mazda will have a PR nightmare if this gets out, contact your local news department and see if they can help.

If i dont get 150k out of this motor i'll never buy a mazda again.

Don't pay them a dime, 50/50 means you will pay more than 4000 euro's for it.
I just came back from my dealership where they showed me another rx8, it's also a 4port like mine and it got 66000 km and the engine has to be replaced because the oil system failed. It's was used as a daily driver by an older man, so it was in excellend condition and not in anyway tuned. They had to measure the compressing and send the results over to mazda, result is they send a new engine, oil system, cat and collector and they have to send the engine back without taking a look inside. Total cost will be around 10000 euro's.So I am also getting really worried about these renesis engines.

You're not the only one who's nervous about the reliability. I'll rebuild if myne blows because I have so much invested already, with the hopes that building it to more precise specs will make it last longer the second time, but I definitely would not buy another Mazda. But, as of now, I am happy with Mazda, and would buy another in the future. The 8 is a great car and I like that Mazda takes risks, such as the rotary engine. I also like their enthusiast driven nature. Hopefully these engines are just flukes, I know all companies have some duds here and there. But it does seem to be alot of them.

i have 19236 miles on my 04 and my service dept just told me that the compression isnt holding and im going to need a new motor.............. now this is two times after the car wouldnt start (from engine flooding) and then them forgetting to hookup a cable when they replaced my starter.

Im very pissed off at this point because ive done what im supposed to do with the service end on this car

Blown Motor
 

Update for those who have been following / assisting on this thread:
Dealer completed replacing the original equipment motor with a factory remanufactured unit today. As part of the service I had the tech pull compression readings on the replacement motor. The compression readings on the reman. motor were actually LOWER than the readings on my original equipment motor!!! Service folks then used an older tester used previously in pre-Renesis days and pulled readings in kgf-cm2 (old meter was based on the metric system) that still were under the factory norms in the Service Manual.

Dealer advised that the test equipment they were forced to acquire to do compression tests on the Renesis had been discontinued by Mazda due to problems with same and they were awaiting delivery of a new unit which was to replace the old unit as of 01/01/2006.

For those out there with access to dealer service information, can anybody confirm this switch out of dealer compression test equipment being mandated by Mazda? I'm wondering now if the readings the dealer pulled on my original motor that were well below factory specs (but still better than the remanufactured motor) were actually erroneous and that maybe the original motor was not that bad after all. :wallbash:

oh dear

The old electronic compression tester,used on 2/3rd gen RX-7s works on the RX-8,or the WDS with a special transducer may be used.See Manual,pp01-10-7.
Rebuilt engines should have come with a compression test certificate ,at least the RX-7 rebuilds did.The compression shoul be above the minimum specification,but the conditions of the test are critical,eg a test conducted with a cold engine is useless for comparison with the values quoted in the manual.The test RPM must be specified,and the graph provided in the manual consulted to evaluate the result.If your tech does not do all these things,the results are useless.
On some new and rebuilt engines,the compression improves with use,it may take 5000mile or more before the peak compression is reached.

Two Rotors:
Thanks for the reply, rebuilt Renesis came with no certificate that was provided to me. Tech did confirm that the tests (both on the original motor and the rebuilt unit) were performed on the motor after warm up to standard operating temperature. You can see the compression test results on the original engine posted by me earlier in this thread.

I appreciate your comment about a break-in period possibly pushing the numbers up on the reman engine, but this unit was WEAKER than the factory engine it was installed to replace by a good margin, and the original equipment motor was well off factory spec itself. Have you seen compression numbers increase on the order of 25-35% when comparing initial install baseline readings to those taken at 5K miles?

In short,I have not seen that much improvement.It is interesting that at our dealership we have only changed one engine so far and that was almost a year ago on a low mileage engine.We used a factory new engine. My view is that 5w20 oil is too thin,I have used 10w 40 since I got it,but I only have 13k miles on it.

Back to my question from yesterday; any info on the comment I got from the dealer regarding a factory mandated switch on the Renesis compression testing gear with an 01/01/2006 cut in date (or thereabouts)? Any experiences to share on the relaibility of the initial compression test rig for the Renesis (that the factory also apparently mandated) versus the past model used on previous RX-7s?

VOODOO8, this is a very scary situation you present. The scariest part is that you have provided lots of information to back your claim......and I believe you. There have been plenty of folks on this forum who've complained about the Renesis and stated they had blown motors without providing any details. You have provided lots of details and anyone reading this thread should be concerned......especially those that purchased their 8 like me. Please keep us all informed of everything that occurs with your car. Thanks

Is it possible that the service people at that dealership are all ignorant chimps and not even qualified to change oil? I wouldn't recommend blowing up at them, but I would recommend talking to the Mazda regional rep yourself. They either mis-diagnosed you in the first place or botched the installation or Mazda sent them a bad engine. In any case you certainly shouldn't be paying 50% or even 5%.

Here's an old thread that caught my attention a while back.. it sounds relevant to the issues addressed on this thread.
https://www.rx8club.com/showthread.p...lity+side+seal

EDIT: Several pages later, it seems RB cleared up a few things, and i quote


Thanks for finding that demob05. It's a great read.

There have been no directions from Mazda to use only the WDS system for compression checks.(at least here in Canada)Normally they would send revisions to the Workshop Manual and this has not been done.The only advantage to the WDS system is that you get a printed report with the data on it---it could be that some district official wants copies of this report.
Have you had a new high torque starter installed?I would be surprised if your man achieved 270 rpm without it.

voodoo, the symptoms you described earlier are eerily similar to what i've been experiencing since last wednesday evening. i initially attributed it to a bad batch of premium chevron, but she still doesn't feel 100% under acceleration, espescially in the mid-high range where the 8 thrives. add to that a blinking cel this monday morning during acceleration following a 5-3 downshift (misfire?), and i'm just a little concerned. i called my service dept. yesterday and will be bringing her in tomorrow morning to check the cel. how long would it take to do the compression test at the dealership?

A couple of hours and a couple hundred bucks should do it. The compression chart provided by MadDog earlier in this thread is the key to deciphering the results. Also being sure that the tech is confident in the compression tester he/she is using and the validity of the output data wouldn't hurt either.

As stated earlier in this thread, and in others, establishing a compression test baseline to then monitor future findings to seems to be a safe and worthwhile investment for all rotorheads to be pursuing with the Renesis (based upon my experiences anyway). Even if you get good readings (which I hope you do!), it is not a waste of time & money IMHO.

BTW - the conversions I looked up regarding pressure readings are as follows:

1 kPa (kilopascal) = 0.010197162 kgf-cm2 (kilogram-force / square centimeter.
1 kgf-cm2 = 14.223343334 psi (pounds / square inch [absolute]).

Yea this is right. People talk about blown motors all the time, but thats all I hear.

while i certainly feel for anyone who has had engine issues that required a replacement, especially when its just dumb f*cking luck, before people start feaking out for no reason, remember, the previous NA rotaries were very reliable historically with many pushing 200K miles.

Mazda tested the shit out of these engines before fielding them, they had too, they had to make sure that the preception of the rotary being unreliable would not come back again. That, and Ford likely held a gun to their head as it was a huge money issue.

All engines have issues and some small % of them fail. We hear about more of them here because so many people use forums to discussion problems.

everyone relax and return to your regularly scheduled forum viewing.

Interesting opinion brillo. Given that there are very few RX-8's that have mileage on them that equal or exceed mine, I would appreciate your providing some facts that back up your postulate that my vehicle is a statistical outlier and I'm am blessed with dumb f*cking luck.

Whether others that read this thread choose to pay attention to the information, or to trust in the beneficence of the Mazda/Ford conglomerate, that is there privlege. I would rather have access to these forms of broad based community information sharing that we have available to us today than to return to the pre-Internet age when a consumer with a problem had no readily available way to communicate with others, share information, and gain a broader perspective.

Voodoo8, I think brillo was saying that there are 100,000+ 8's out there and then a very small percentage of those are on this board and then another even smaller percentage of board members have had an engine replaced. I really do hope yours gets fixed correctly, but the engine replacement is not a huge problem in the grand scheme of the 8 and really isn't even a big problem. Happens everyday to other new cars. Brillo, correct me if I am wrong in what I thought you were saying.

Good Luck, keep us informed.