Hi there, I've just registered to the forum, but I have been reading for quite some time now, and I have to say, I feel like most of your are more knowledgable than the "mazda certified" mechanics that I've dealt with.

That being said, I'm having several issues, and I've read what feels like hundreds of posts on here trying to figure it all out. I know some have been covered, but wasn't quite sure where to post my question otherwise, so...don't be mad

I've had the "marbles in a can" problem for a while, very irregular and inconsistant, needless to say that the stealerships "can't duplicate". Mazda tech says shutter valve is fine.

Feels like the timing is off, I'm not cueing a misfire...and it doesn't feel like it...but this is my first rotary.

So, I also have a god-awful idle, constantly stands around 800, but in decel to idle has dropped to 500, and obviously stalls. (this doesn't happen every time)

Dealerships says there isn't anything wrong. Since it won't pop a CEL or send a code, they can't "verify any of my concerns"...

I did recently discover that the electrical harness attatched to the brake fluid resevior has a broken wire, im wondering if that could have shorted..stopping the CEL from registering?

My goal is to just replace the cat, which I recently discovered was GLOWING RED...but im sure the dealer wouldn't notice something like that...and I guess just do coils\plugs\wires and hope i take care of my timing problem. Just hoping to see if anyone had insight that I had missed.

thanks
04 m/t
60,000mi
stock

 

Do you know if there is a previous engine replacement already on record?

If the cat was glowing red, then it is failing bad, and could be the source of some of your issues. Continuing to drive with your cat that bad can cause additional damage and problems, including damaging or destroying one or both O2 sensors, causing localized heat buildup in the engine breaking down oil faster causing excess wear, and/or over stressing the seals from not being able to evacuate the exhaust. Get that cat replaced ASAP. If you have to, pull the cat off yourself, look inside and see a damaged honeycomb, take pictures and bring it to the dealer. It is what I had to do. Dealer ordered me a new one and put it in under the mandatory federal 8yr 80,000m warranty on the cat. You are still within that, so get that taken care of.


Now, your cat could also have failed due to an ignition problem, not igniting enough fuel, and that can also cause your unstable idle problem. 60,000 is right for another coil/plug/wire change anyway (every 30k), so you can't go wrong there and it isn't wasting any money.

Short term, do a ecu reset (20-brake pedal stomp or battery disconnect), and see if after a few drive cycles things are improved any. With the cat messed up, it probably won't help much, but once the cat gets replaced, put that on your to-do list. Another easy thing is cleaning the MAF sensor, just get a can of MAF sensor cleaner, pull out the MAF sensor (carefully), and hose it down, let it dry, and replace.



If the above doesn't return your 8 to normal operation, and you still hear the marbles in a can, you can disassemble your upper intake manifold. Takes a few hours to pull apart and put back together, but it will let you see if your shutter valves in your intake ports are functioning correctly or are carboned up heavily, etc...

If all of that still doesn't fix your issue, get a compression test done at the dealer...it might mean a new engine.

The symptoms match alot of individual issues, so just gotta poke through it.


And yes, the collective knowledge here is far higher than 99.9% of mazda mechanics individually. If your dealer isn't exclusively Mazda (shares other manufacturers), then the chance of a good mechanic drops considerably, to almost nil.

 

For sure Plugs/Coils/Wires but if the Cat is glowing red it is toast. I see you have 60k mi. Someone else could pipe in but I beleive the Cat is covered under the "Emmissions Warranty" till 80k mi. Get the C/P/W and do them youself. Buy the parts from one of the vendors here. Very easy job...

 

Remember MIAC is usually heard at high RPMs in any gear and then goes away on the shift until once again at high RPM's. The sound itself only comes from the glove box area, so if you are hearing it coming from anywhere else, the it may actually be the SSV or in that area. We'll deal with MIAC later, if that is truly what it is. I just wanted to say that much because RIWWP just about covered it all at the moment.

You could pull the CAT off and assuming the honeycomb is crumbling, just knock it all out of there, but since the 8 year 80k still applies..........go get a new one.
I think the CAT is your #1 issue as well, but it is time to think about coils and plugs AFTER you get that CAT taken care of.

 

You guys are awesome.

I haven't driven the car much at all since I found the cat issues; I was in the process of odering one when I saw the post about the warranty, but half of me wants to exclude the dealership from ever touching my car again.

Last time they had it, they told me that the air filter was soaked in oil due to overfilling. That I have to be careful when I put oil in because it got on the intake boot and so on and so forth...
funny story...they did my last oil change...

As for the plugs coils and wires, just did them not more than 6 months ago, but again, Mazda did them, so who knows if it was actually done.

MIAC happens sporatically, but typically starts at 5K rpms, and I have to push until the sound stops before I can shift, or the next gear has massive lack of power. I don't know if that makes sense, so for example I hear the sound at 5K in second gear, shift when the sound happens, 3rd gear at full throttle won't go past 3 to 4K rpms, at 35mph...

I'm dyin here, I'm in love with the car...but I can't afford a new motor.
Thanks for the replies!

 

^..................well, if it comes to that the warranty on the motor is 8 year 100,000 miles......assuming you have all your oil receipts or you get Mazda to do it anyway(yes, that has been done without receipts, but sporadically).

I think you are hearing the noise and other issues you describe in the post directly above due ONLY to your CAT. There maybe be more after that, but...............

Have you taken the CAT loose or off and looked inside? The noise you think is MIAC might just be the crap rattling around in the CAT and it can't evacuate all the exhaust..........thereby causing all sorts of issues.

Keep in mind, I am not an expert and not really a gearhead, but I have been around here long enough to pick up a few things here and there.
I'm sure someone more knowledgable than I will pipe in but RIWWP did a helluva job in his post! Read that again and again!

 

You have a BAD Catalytic Converter. Drive the car around until the cat glows red and stick it into the dealers face. Take pictures of it at night. Take the pics to the dealership.
Make them warranty it.
If they will say they will charge you to look at it, tell them if it's bad your not paying for the inspection because of there lack of mechanical troubleshooting ability.
Tell them a bunch of guys on the internet have diagnosed your car with out even seeing it in person.

Or find another dealership.

 

Thanks. My first thought was that the sounds was my cat falling to pieces. Its happened before, was an all too familiar sound, guess I was hoping for a change in pace, lol. But its a little more comforting that you all seem to think so as well.
as for the oil receipts, i do it myself, except for the last that I let mazda do, only because they already had it in the shop. So I guess I'm beat for reciepts. Wish me luck it doesn't come to that, or I'll be moving to a Ford forum unfortunately! Thanks again.

 

I'll pay money if the OP video's this as he pulls into the dealership and films all the way up to your last sentence!

 

That would be a good movie. I think more people should film their experiences with the dealerships/service departments/technicians. Walk in with a camera and start asking questions about why your car is doing what it's doing. Oh that would make for some very interesting footage.

 

Yup. The massive loss of power is definitely your cat. No air (exhaust) out, no air in, can't create power, the fuel still is getting dumped into the engine, being a liquid is still getting out of the engine as it sweeps around, igniting in the cat, turning it a firey red.


This can and HAS started vehicle fires. Now that you are at the massive power loss stage, it will acclerate the failure faster and faster, increasing additional damage rapidly. I would expect that within 2 days you will not be able to maintain highway speed in any gear.



I know this because it is what happened to me. I thought it was failing ignition, and I didn't consider the cat until it was critical, and only diagnosed it when it didnt matter what gear I was in, I couldn't get above ~50mph.

This is what my cat looked like: The chunks you see are whatis left of the FRONT honeycomb, what you can see is the rear. The front one powdered up and packed the 2nd, clogging it almost completely. that pipe is the rear O2 sensor which sits between the 2 honeycombs...


I had to borrow someone's midpipe for 3 weeks waiting for the dealer to get a new cat in. Make sure you have an alternate plan, you shouldn't be driving your 8 in this condition


Before this failure, I had a top-notch 8, could get 24mpg at a whim, ~25s 0-120 times, one of the heathiest strongest engines alot of friends have ever felt from an 8.

Since I have had nothing but issues relating to ignition, AFR, stumbling, etc.. and my compression plummeted from what was probably the high 8s or low 9s down to barely passing.

Get that taken care of ASAP.

(this is one reason I now consider a midpipe a reliability mod....)

 

^............I plan to barbecue this weekend, you got any of those left?

 

 

I just got queezy looking at that cat...ugh, bad memories...note to self, call dealership tuesday, no rx for memorial weekend...plenty of time to read more posts!