Okay, here we go again. So, fresh Reman Engine about 50 miles ago. The first couple miles I had a flashing CEL and stalling problems occuring at idle. Took it to the dealer, and they had the fuel injector wires mixed up, got car back and runs like a beauty. This morning(50 miles later, 2 days later), i start the car up and get a flashing CEL. All of a sudden now, I can hear what sounds like a can of coins rattle from inside the car, windows up, and whenever I accelerate is when the noise occurs. Any ideas on the problem? I also stopped the car a couple times to restart, and no more flashing CEL, no other problems are happening but the rattle.

After all the above occured, i disconnected battery to reset. And idk if it was doing this before, but also seen white exhaust smoke on start

 

Take it back to the dealer.....reman problems are warranty issues and as you have seen there are huge potential for problems

 

That is exactly what Im going to do. I just unplugged battery, AND reset ESS because they never cleared the codes when I had got it back from them, and it had the misfire codes still stored. I just went on a 10 mile drive, stopping 3 times and restarting engine, no codes have came back. If it happens again, 100% going back to them.

 

Good job on doing both resets, most people usually forgo one of them even though the two systems are intimately linked.

 

If it wasnt for this forum, people like you and everyone else id be SOL. Since they hadnt cleared any of the misfires or anything, how exactly does resetting the ESS work? Im a bit confused on that, just hoping it worked though.

 

Well it's not really resetting the ESS. The 20 brake stomp is the way to clear the KAM, while the battery reset (I prefer the TEST mode) is how the NVRAM is cleared.

The NVRAM (Non-Volatile Random Access Memory) is a portion of the ECU's memory that contains fuel trims and target AFRs under various conditions. It essentially is the memory that is used to make the car as efficient and as high preformance as possible.

The KAM (Keep-Alive Memory) is a portion of the ECU that contains all sensor profiles/calibration settings. It basically maintains a base set of guidelines to get the engine running (not running well, mind).

The two memories work together to make the car work well in all situations. The NVRAM is a modifier of the KAM. The KAM takes values hardcoded into whatever tune is running and uses those as a baseline on how to run the engine. This is the memory that takes over when the car is in an open loop condition, or a sensor fails. In a closed loop (normal) condition the NVRAM is accessed and new performance targets are put in action based on the fixed values provided by the KAM.

Resetting only the NVRAM or only the KAM can work, but it does weird things. If only the NVRAM is reset the engine will run on established KAM values until it sets new NVRAM values. It's not really a big deal except when it comes to long term fuel trims (a baseline fuel trim that is not updated as often as the short term fuel trim). It can work, it's just not the best thing.

Resetting only the KAM is a much worse thing to do. The ECU will attempt to establish new sensor profiles/calibrations, and it will do so perfectly. The massive problem comes when the NVRAM is accessed with the new KAM settings. The ECU will continue to reach the old NVRAM sensor targets based on a new scaling for sensor values, which can lead to a host of unreported errors like: ultra-rich conditions, ultra-lean conditions, excessively advanced or retarded ignition timing, detonation, even misreported misfiring.

Think of it this way:



Sorry if I can't explain it well (and sorry for the weird flowchart, I don't know why I drew it that way). If MazdaManiac was around he could do it better, but hopefully that gives you an idea of what they each do.

 

Oh no, you explained it pretty straight forward to me. Its just really unique to me how it works now that you explained it, appreciate the diagram too man! Yeah CEL came on again after about 20ish miles(5 drive cycles) but didnt see if it flashed cus I got busy right after startup -.-, when I wakeup tomorrow im going to run to autozone to see what popped up and go from there

 

Okay, so i do indeed get a Blinking CEL still, but i noticed it only happens on cold start, and idle is a bit spuddery. Just got codes checked AND, i have p0300 random misife, p0302 cylinder 2 misfire, and they replaced the secondary air pump(for free, cus of hassel), before replacement i had p0411, and that has now came back also for secondAry air injection. The only problems i literally have is blinking CEL on cold startup, and a spuddery idle, other than that car runs fantastic. And idle at stoplights while holding brake and what not is perfect. Im sure i had a vacuum leak prior to new Reman, but it never had any flashing CEL though. Thoughts?

 

Next time you let it sit overnight. Crank the engine with your foot holding the gas pedal to the floor. Just briefly, don't start it.

Then pull the lower plugs and see if you have coolant on them.

 

Tomorrow i work early, but just have enough time to drop it off at the dealership(right by my work), should i do that, since this wasnt happening prior to new Reman, so technically they shouldnt charge me? And tell them about possiby coolant problem perhaps? Everytime i gas up, i do check fluid levels, and it seems fine

 

Is there any warranty on that reman?

I'm not saying that there is coolant on the plugs, but misfires on cold startup could easily be coolant that has drained into the engine overnight. And if a reman fails really early, it is usually a coolant seal failure. You have to check it when it's cold though. Or pull an oil analysis looking for coolant in the oil, or pressure test the coolant system. Pulling the plugs is the easiest one, but if you bring it to a dealer and ask them to check, they won't find anything, since it would be hot and not sitting long enough.

Of course, this might not actually be the problem, but it's happened a fair amount so it's worth checking.

 

Yes, I have a 1 year/12k warranty on the Reman, and I have no patience, i wont have much time tomorrow to jack up the car and stuff for the plugs, let alone i dont have the plug tool for it atm, shame on my ***. For the oil one? How do you check that, just pull the dipstick?

 

No, you have to do it during an oil change, capture several oz of the oil from the middle of the oil stream that is draining in a special container and mail it off to Blackstone Labs.

Pulling the plugs is the easiest, and that is where you are currently manifesting symptoms, so it's my recommendation.

 

Okay, will drop it off at mazda for the hell of it, even maybe tell them exactly what you said, give them permission to let it sit overnight, if they dont do that, ill do it anyways once i get the car back, ill pull the plugs and see. Yeah because it only flashes on very cold starts with spuddery idle.

 

A little bummed, i would think since i didnt have no misfire codes prior to the Reman put in they wouldnt charge me, but yup, charged me 115$ for a diagnostic. Wont findout till tomorrow morning.

 

If you took it to the same dealer that did the install....and with all the issues that you have had...there is no way that I would have paid a diagnostics charge

Talk to the service manager...and if you get no resolution...call Mazda NA

 

Yeah , same dealer, same people i even talked too, thats why i was caught off guard.. They have been so helpful so far, even gave me a secondary air pump for free for all the BS thats been happening. I just am mad because they were like "its probably a coil", nah i got those changed 200 miles ago, and then they kept saying just drop it off tomorrow morning, but that would defeat the purpose of the diagnostic cus it only misfires cold starts, so I just left it there. Going to see what they say tomorrow and will let them know this happened next morning after install, i shouldnt have to pay a dime.

 

I also read vacuum leans possibly can cause misfire, cus even with new secondary pump, code p0411 triggered again, but well see.

 

Mazda said one of the coils were bad, i thought a failing coil would cause misfire on all starts? Can they really just cause misfires on cold starts? And was only 500 miles in on coils, guess ima go to autozone to get another one.

 

Take Mazda's failed coil diagnosis with a grain of salt, a big grain. More like a block really. The official test doesn't really test the parts that are important.

Though, in theory, yes, if a coil had an internal defect that kept it from working right until it heated up, then it could cause this. Would be the first time I've heard of it, but it isn't impossible. Especially on coils that are "new". Internal defects are always possible and are usually wierd.

 

Yeah well see what happens. Will update yall, ill have the part in today and whenever car sits for 8+ hours ill tell the update.

 

Okay so the old coil they pulled has green residue on it?? On the underside of it?? But not inside

 

Spilled coolant?

 

Yeah i was worried and called right back, he said during all that he never noticed any leaks or anything, might of just spilled it, cus it isnt inside or near the connector

 

I'd bet a defective coil.

I mean, coolant is possible, from the overflow onto the fans that DOES spray it all over the engine bay. But it would be obviously elsewhere too, not just a mention on that particular coil. So I'd bet it is accelerated corrosion, and the most reasonable cause for that would be an internal failure on the coil that is grounding through the body to the mounting plate, which would certainly disrupt ignition pulses. If this was a 10,000 mile coil, I might start digging elsewhere, but manufacturing defects do tend to show up really fast when you inadvertently buy a bad one.