Blown Engine, What To Do?
 

It's been a long time since I've been active here on RX8Club, and I'm coming back with sad news, looking for advice.

Earlier this year, I was driving to work and my engine stalled every time I got close to idle. I took it to Trussville Mazda in Trussville, Alabama. Their diagnosis was that carbon build up had caused the apex seals to wear down, resulting in compression loss. The low estimate was $3800 to fix. From what I understand, that's replacing rotor housings, seals, spark plugs, etc. What they call a "new engine." To take care of everything (plug wires and other related components), it would be $5000. With a current blue book value of around $5800, it's not worth it to fix it. To make matters worse, my wife and I just had our first kid, so money is tight. It'd be a big investment to fix the car even at $3800.

I tried to contact Mazmart since they are based in ATL and helped someone else on the forum with a rebuild, but I never heard back.

I figure I can sell it as-is, try to part it out, or hold onto it in the hopes of eventually being able to do something with it.

Anyone have any advice, know some one that works on RX-8s, would want to buy a part car, etc?

Thanks to everyone for sharing their thoughts.

Not that I know everything there is about the motor, but how sure are they that it's the seals? How many miles do you have on it? I had a simalar issue, but it didn't stall at idle, turned out to be a plugged up catalytic converter. only about $300. Might be worth a second opinion, I don't quite understand why low compression would stall at idle, I may be wrong though, like I said, I don't claim to be an expert.

It's my assumption that they checked the seals and compression to arrive at the diagnosis. They said the cat still had some milage left on it. I think I'm at 130,000 miles. I had my engine replaced around 50,000 - 75,000 in 2007 for carbon build up when Mazda was still researching the issue. So, this engine is in the 50K-75K range. I believe the cats are supposed to last 150K miles, anyway.

How'd you figure out the cat was clogged? Did you notice or did a shop figure it out? I guess I could pull it off some time and see if there is a way to determine if it clogged (blow air through it?).

The problem is, according to them, the colder weather will prevent the loss off compression and make the car seem OK. It was summer when I took it in, and I haven't driven it since then. So, I'll have to figure out if I can even get it to stall now before I could rule out the cat. But, like I said, I assume they ruled out the cat.

pull the front of cat down and look inside with a light. if the honeycomb is melted/destroyed/missing/ cat is dead. you need 3 numbers per rotor and cranking speed to determine compression

My car has 92k mi. on it and the cat was blown. I didn't notice any drivability issues.
I pulled the o2 sensor and looked inside with a flashlight. I could see that the rear substrate had a golf ball size hole in it and the back side of the front substrate had lots of cracks/chipping and looked like it was going to go sooner than later.

As I understand it, low compression would cause very slow starting and stalling in low RPM so it could be the issue as the dealer said.
Try performing a de-carbon of the motor and see if it improves. I think that I heard somewhere that carbon can make seals stick or cause junk to bind which causes compression loss.
I'm new to rotaries so I'm just going by stuff I have read. I could be wrong.

My cat was bad at 105k miles, I think the 150 number is a bit ambititous. I was low on power at the low end. I would have a good indy shop perform the decarbon/seal rejuvination procedure. Something about oil or trans fluid in the spark plug hole to clean the seal and make them seal better. I had a shop do it for me after I flooded it and couldnt get it restarted, certainly made a difference. I would be very surprised if your engine is bad after only 60 or 80k miles. Good Luck!

I'm a PM away. I can be reached by phone at 800-221-5156. I would love to talk to you about and hope that I can help.

Paul.

I cannot stress enough how lucky you are to be relatively close to Mazcare in Marietta GA. Charlie just rebuilt mine. Unless you are very savvy at pulling and reinstalling, you need a manager of this project. There's no one better in GA than Charlie. Drop him a line: mazcare.com

... and join garx8club.com

Good combination! :D

Thanks for the feedback, everyone. I had no idea there were de-carbon procedures. Wish I would have kept up on the forums better. I'll get the kit as soon as I can and see how that goes.

Paul, I'll be in touch soon. I appreciate it.

I was recommended by a local dealership to run a few gallons of high test racing fuel combined with high test regular fuel and that can remove carbon deposits as well.. I had other issues with my car though seemingly unrelated (electrical) I posted about in another thread so not really sure if it worked as repairing those issues did the trick but as always it was probably a combination of several things that helped out..

See here the other thread: https://www.rx8club.com/trouble-shoo...se-box-205297/

Thanks for the idea. I have yet to purchase the carbon cleaner from Mazda, but anything is worth a shot. I'll try that next.

Man...I'm sorry to hear the news...I have been concerned due to reading the forum almost daily...about the carbon build-up...I have had mine a year now and I decided that I would try the Seafoam carbon cleaner...relatively easy and somewhat cheap...I hope, to those that may know more about this issue that it wasn't stupid for me to do that...I have read and experienced if you redline at least once a day..that is sure to clear the carbon...I have a lead foot so that's not a problem for me...plus I love to hear the engine...I don't know much about the "cat" but will definately learn more...I have a stupid question though...please be forgiving in the comments: Can an AT stall or is it just MT?

^.................Yes, an AT can stall for numerous reasons.
Not going to address anything else you wrote for the time being.

Personally I'd try it together, not either or, use the carbon cleaner and follow up with a few gallons racing fuel and as it comes to my mind now if your car has been sitting that long you should drain the tank anyways as the fuel has aged & lost octane but at minimum add the racing grade fuel to what's in there already, depending on where you're located many Sunoco's have racing fuel, the one near me doesn't allow to pump it into your car directly though so bring a gas can just in case..

One of the guys at Serra Mazda independently told me that revving high often will decrease the likelihood of carbon build up. Unfortunately, I quit driving my car really hard awhile back due to getting old, or the boring commute, or something. I'd keep on the high revving and the seafoam if I could go back in time. For the record, the guy at the dealership also said that ATs were having more of a problem. My guess is that it's due to the AT not revving the car as high as a MT. So, just keep up with the high revving and seafoam in the long term. That seems like the only shot any of us have other than replacing engines every 75,000 miles or so.

I have a spare 6 port factory reman sitting in my garage with only 13k miles on it...

How old are you? I'd have to have moss growing off of me to stop me from enjoying the sound and feeling of any high revving engine let alone a rotary..Trust me I'm not a spring chicken either, sadly enough :sad: .. But yes the auto does have issues because most owners who purchase them don't drive them hard enough regardless of the difference in redline.

I'm 31. I think it's more of the boring commute that did me in. :P