N7turbo
2023 CX-5 2.5T ... 2024 MX-5 RF GT
Just to be clear, I put the EPB on, car in drive. Let off the brake, idle increased. Depressed brake pedal, idle dropped.
Strange 2.5T Engine misfire problem w/multiple choice answer game. Come play.
- Thread starter Tchman2016
- Start date
Good question!... I'm going to check those again tomorrow, I had seen the short term showing -4 or -7 percent at one point but don't remember exactly both readings.
Yes that's exactly the scenario TY!
N7turbo
2023 CX-5 2.5T ... 2024 MX-5 RF GT
Oil analysis to check for potassium.
Ahh, to indicate the presence of coolant.
My last oil change was at 34,500 miles and I'm currently at 36,200 miles. Is that a long enough period to show results? The coolant reservoir also shows coolant below the low mark. Halfway between empty and low.
I'm wondering if a compression test of each cylinder would be in order here.
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Ok, here are some live data screenshots from a drive this evening I recorded.
The engine exhibits the exact same problem to the same degree as it did before I changed the plugs today. Like the plug change did nothing. I honestly now think it has nothing to do with ignition coils or plugs.
Now i'm thinking it's timing related. That would make more sense. Oil control valve possibly? Burnt exhaust valves? Faulty EGR valve? The engine literally sounds like its knocking when the idle is so slowed and I hear a tin aluminium metal sounding clinking noise (similar to the way the little tab on top of a soda can would sound if you break it off and put it inside the empty can and shook it) when I rev the rpms a little like something is broken or loose inside but it comes and goes. Really bizarre
Anyway, i'm considering removing the new plugs, putting back the old ones and taking it to the dealer. I don't want them to say something to the effect that they see new plugs and give me a headache or trying to blame something on me. This may be over my head.
What do you all think? Something is really wrong here and i'm just drained from it at this point. Thank you to each of you all for your help and insight.
The engine exhibits the exact same problem to the same degree as it did before I changed the plugs today. Like the plug change did nothing. I honestly now think it has nothing to do with ignition coils or plugs.
Now i'm thinking it's timing related. That would make more sense. Oil control valve possibly? Burnt exhaust valves? Faulty EGR valve? The engine literally sounds like its knocking when the idle is so slowed and I hear a tin aluminium metal sounding clinking noise (similar to the way the little tab on top of a soda can would sound if you break it off and put it inside the empty can and shook it) when I rev the rpms a little like something is broken or loose inside but it comes and goes. Really bizarre
Anyway, i'm considering removing the new plugs, putting back the old ones and taking it to the dealer. I don't want them to say something to the effect that they see new plugs and give me a headache or trying to blame something on me. This may be over my head.
What do you all think? Something is really wrong here and i'm just drained from it at this point. Thank you to each of you all for your help and insight.
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- NS, Canada
I had these issues on my 2018 Mazda6 Signature. it was a dead cylinder and required an engine replacement.
Someone else on the site also had the same issue on their cx5 with the same engine.
www.mazda6club.com
Someone else on the site also had the same issue on their cx5 with the same engine.
2018 Signature - MIL - Misfire cylinder#2
Howdy, Just thought I'd share the latest with my 6. Current mileage is 105,000kms. Condition has degraded drastically. Car is now sputtering bad when stopped in drive, feels like it's going to stall. Idling low at 500-600 rpm. I have a check engine light now and it's throwing Misfire in...
Maybe EGR valve is stuck open? Thish would reduce power, increase temps, and cause a crap idle.
OMG i'm going to throw up! That's the exact same issue i'm experiencing. I'm so sorry to hear this happened to you and that whole experience makes me sick to my stomach.I had these issues on my 2018 Mazda6 Signature. it was a dead cylinder and required an engine replacement.
Someone else on the site also had the same issue on their cx5 with the same engine.
2018 Signature - MIL - Misfire cylinder#2
Howdy, Just thought I'd share the latest with my 6. Current mileage is 105,000kms. Condition has degraded drastically. Car is now sputtering bad when stopped in drive, feels like it's going to stall. Idling low at 500-600 rpm. I have a check engine light now and it's throwing Misfire in...
I don't understand why there is no code thrown for ANY of the cylinders misfiring like that let alone no check engine light on.
Would a dead cylinder cause the other cylinders to misfire like that?
I guess I need to throw in the towel, put the other plugs back in and take it to the dealer.
Or should I leave the new plugs in and drive it around until a code in the PCM appears or put back the previous plugs and drive it around?
Would their scan tool show a misfire code that mine is not for some reason?
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- 2017 CX3 AWD
In the thread linked above, someone noted the MAF sensor as the culprit. You can explore that aspect yourself. If all your cylinders are misfiring, the cause is hopefully something other than a dead cylinder.
I learned recently that the scanning process is not absolutely precise/perfect. The hardware/software combo can lead to different results. See if you can find a different connector or app to check again. Auto parts stores don't always have time to run scans. There are still things that you can do before turning it over.
With an extended warranty contract, is the dealership still likely to decline service? You shouldn't have to worry about the new plugs.
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- 2017 CX3 AWD
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- Canada
You raaang?
I've actually been watching this thread to see what the solution was and to offer help where possible. Unfortunately I've never run into this problem, and I've never seen any other reports on the forum about this. I was planning to try checking idle RPMs in Drive to check for idle changes on and off the brakes, but it looks like that's already been tested and confirmed by others as normal (outside of the misfiring).
@Tchman2016 I'd check the fine print of your extended warranty to make sure you follow the process outlined in making a warranty claim. Sometimes there are disclaimers saying you need to have a diagnosis performed by "X" dealer before the claim can proceed, so it would be a waste to take it to "Y" shop, have it diagnosed there, and then try to file a claim and have it rejected just because you didn't go to the "X" dealer for diagnosis.
If it were me, I'd put the original plugs back in (in the same cylinders if possible) before taking it to the dealer for diagnosis. When they run through their troubleshooting, the plug condition would likely help them figure out the underlying cause.
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- Canada
Also, on the topic of no codes thrown for a issue like this.. I'm reminded of the time my rear differential took a s*** and I also didn't get any stored codes. I had a Honda dealership (who did an unrelated collision repair) tell me that if there was a problem with the AWD system, I'd see a code. And then when I brought my car to a Mazda dealer, they said the same thing. Meanwhile I was driving around with FWD only, and pulled the rear diff drain plug to see chunks and shards of metal mixed with gray, silvery fluid coming out, and no freakin codes stored.
It doesn't help your situation, but this is definitely one of those things where there should absolutely be a code present to help you figure out what's wrong.
It doesn't help your situation, but this is definitely one of those things where there should absolutely be a code present to help you figure out what's wrong.
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- NS, Canada
I eventually started getting codes but it took several months. Codes usually happened in parking lots when I was backing in/out of a spot or other slow maneuvers.
Mazda and my dealer were helpful through the process.
I believe it was only a single cylinder misfiring. Not all of them.
Basically if car was in gear and I’d put the ebrake on and let off the foot brake so there was some load on the engine. You could feel it was running rough and idle would dip down below 500rpm.
Daily driving on the highway you’d never know..it was slow speeds or at a stop where it felt off.
Yes I saw that too but there are so many variables it's like pulling straws!
Yes its true and so strange that different scan tools and software can show different stats and codes.
I looked at the data from the maf sensor and it is operating with the voltage and grams/second fluctuating depending on how much I rev.
The extended service contract is the top of the line Mazda OEM Platinum exclusionary one with zero deductible that covers everything except specifically spelled out items like glass, rubber, trim etc. It is not a third party warranty. I would never buy one of those. I hate dealers scumbagery, incompetence, and overall hastle it is every time you try to bring in for warranty work. They try so hard to deny any problem even exists and just say there is no issue since all they want is customer pay labor. Either that or they are just so incapable of diagnosing anything and make up the dumbest things to get you to do services not needed. It's a hastle but what is one to do?
Lmao YES!!
Could be too. So many possibilities but can't just start replacing everything with the parts cannon on my dime
Ahhh! Yes exactly it, you'd never know during normal driving which is crazy. Only doing the standstill idling in drive with foot on brake or slow maneuvers is when it strikes and those exact symptoms show.
I just don't want to drive the car around hoping a code will store or cel pop on dash and do more damage to the cats.
The flip side is the dealer may say well there isnt a code and the money light is not on so come back when it does, all the while having a horrible running engine that they can see but wanting me to go away and do more damage, rather than investigating on their dime. It's ridiculous and manufacturers just hate paying for stuff.
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- NS, Canada
You could simply pay them to do a compression test. if that is indeed the culprit, that will identify it and give them what they need to open a case with Mazda.
Haha the all knowledgeable sm1ke has entered the chat! You're a good man thank you.(Actually everyone here is)You raaang?
I've actually been watching this thread to see what the solution was and to offer help where possible. Unfortunately I've never run into this problem, and I've never seen any other reports on the forum about this. I was planning to try checking idle RPMs in Drive to check for idle changes on and off the brakes, but it looks like that's already been tested and confirmed by others as normal (outside of the misfiring).
@Tchman2016 I'd check the fine print of your extended warranty to make sure you follow the process outlined in making a warranty claim. Sometimes there are disclaimers saying you need to have a diagnosis performed by "X" dealer before the claim can proceed, so it would be a waste to take it to "Y" shop, have it diagnosed there, and then try to file a claim and have it rejected just because you didn't go to the "X" dealer for diagnosis.
If it were me, I'd put the original plugs back in (in the same cylinders if possible) before taking it to the dealer for diagnosis. When they run through their troubleshooting, the plug condition would likely help them figure out the underlying cause.
Yes, i'm going to do exactly that, put the original plugs back in the same cylinders ( I kept them in order) and make a dealer appt.
The warranty is Mazda OEM Platinum exclusionary with no deductible. So that's a huge plus if they come through.
I'm wondering if I should suggest to the dealer that they boroscope and run a compression test on all cylinders as well as a leakdown test and offer to pay for those services out of pocket as a gesture of faith they will want to try hard to find the issue and not have to depend on warranty diagnostic and rush. What do you suggest?
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