Brand new Mazda - Has Rough Idle - feels like it needs a tune up

Watch out nXt. Mike the big bad wolf is gonna lambaste you with the owners manual quotes. lol!
 
+2 unless the engine is suffering preignition (pinging) using higher octane serves no benefit. As for rough idle at start up I would not necessarily call it rough like it's missing but the catalytic warm up is normal. After the blue light goes out should be smooth as silk. Knock on wood but ours is so smooth it's hard to tell if it is running.
 
+3 on the octane opinion and smoothness. If I reeaaalllllly concentrate, I can feel the closed loop cycling which varies the idle rpm a tad.
 
Apparently the transitional fuel up here (winter to summer) has been rumored to be less than perfect, so I added some 91 octane (it took about 10L to top up the tank) to see how will this affect the idle. Not sure if it had a chance to mix up properly yet, but the typical rhythmic idle appears to be somewhat smoother. The random "knocks" are still there though. Will give it some more time to mix up; maybe even do a full tank with high grade fuel next time. If the engine mounts were loose or somehow defective would that result in just harsher vibrations or choppy/random ones?
 
+2 unless the engine is suffering preignition (pinging) using higher octane serves no benefit. As for rough idle at start up I would not necessarily call it rough like it's missing but the catalytic warm up is normal. After the blue light goes out should be smooth as silk. Knock on wood but ours is so smooth it's hard to tell if it is running.
Using a higher octane, theoretically, could result in higher performance, if the engine (tuning) was designed to take advantage of it. Could. If. I haven't heard of one that does. I don't believe a modern car will ping to any detriment with any commercially available gas (at least in the US). All cars will be run right at the edge of pinging, as that is the most efficient point of operation. The warmup phase of the SKyActive engines is much rougher and louder than normal operation, but not really bad, and if I shift into gear while not moving, the idle slows down and is smooth. Once it warms up some, before the blue light goes off, as you say, it is hard to tell it is running.
 
CX-5 fuel recommended by Mazda is 87, works as expected.
 
Scratch that. What I thought was improvement due to the added 91 octane was only temporarily. It appears that the intensity of the vibrations changes from time to time (even from one stop light to the next). Sometimes is barely noticeable, other times is quite annoying actually. Now trying to figure out if my driving behavior has an effect in any way.
 
Is your AC cycling on and off (which happens in defrost mode as well) when the idle gets rough? Could be a faulty compressor, just something to take a look at.
 
Apparently the transitional fuel up here (winter to summer) has been rumored to be less than perfect, so I added some 91 octane (it took about 10L to top up the tank) to see how will this affect the idle. Not sure if it had a chance to mix up properly yet, but the typical rhythmic idle appears to be somewhat smoother. The random "knocks" are still there though. Will give it some more time to mix up; maybe even do a full tank with high grade fuel next time. If the engine mounts were loose or somehow defective would that result in just harsher vibrations or choppy/random ones?

With random knocks and rough idle it sounds like a bad/clogged injector to me.
Try some injector cleaner in a tank of gas. If that doesn't work, take it to the dealer for new injector.
 
With random knocks and rough idle it sounds like a bad/clogged injector to me.
Try some injector cleaner in a tank of gas. If that doesn't work, take it to the dealer for new injector.

Fuel additive treatments specifically not advised by Mazda. Tie it to dealer if something is wrong during warranty period.
 
Hi All,

Just looking for some answers - and feedback. Hope you can help.

I purchased a new 2014 CX-5 Touring FWD June 21st 2013

Everything was great for the first 13 days. After that, I noticed the car started to shake in idle. So I call the salesman who sold me the car and he told me to bring it in to have it looked at by the service team and brought the car in July 3rd. After the service team went back and forth with Mazda corporate, they tell me its the gas. So I do as they instruct and burn up what was in the tank. Then they tell me to fill up and burn 2 more tanks. (all the while the car continues to shake with a rough idle and feels significantly worse and now happens in all gears) finally in late August - I am told (and I quote) "this is a normal characteristic of the vehicle." To say the least, I was not happy with this response So - I bring it to another dealer - and yesterday (after finding my record in the computer) this guy tells me the same thing.
He says that its they skyactiv technology that causes the engine to 're-circle' and that is what I am feeling in idle. (NO ACCESSORIES are on when this happens.)

So - They expect me to believe that they knowing built a car (that costs $30k on average) to PURPOSELY SHAKE AND GIVE YOU A ROUGH IDLE. Are you kidding me? (pissed)

The service manager suggested that I can have a 'flight recorder' installed so they can monitor the reading from the computer - so they are putting it in today and I should have my car back tomorrow - but this thing shakes every time you get in it and they keep telling me that "ALL TESTS ARE COMING BACK NORMAL"

Has anyone else had the same experiences? OR is your CX-5 running beautifully? Either way, I would love to chat with you regarding your experience.
Please message me.
Thanks so much and I look forward to hearing from you.

Oh and PS - I'm lucky if I get 22-25 MPG (City/Highway mix)


Hello

Did you get the issue sorted? I am also having the same rough idle and low mpg issues with my 2014 CX-5. The local agents do not know what to do so they are contacting the Japanese support line.
 
This doesn't instill dealer confidence when there are TSB out on a condition and dealer states ALL IS WELL AND NORMAL. Ed
 
ch-5lk do you mind describing what do you perceive as rough idle. A lot of people describe the CX-5 idle as "silky smooth" and imperceptible, but then again not everyone is sensitive to those things. I myself consider the idle of my 2014 rough. It not just that though, there are two very distinct and apparently independent "cycles". The first one is very regular vibration that is not always present; still trying to pin it down but have made some definitive observations already. The second is always present and feels as random knocks, like misfiring. Those knocks range from couple per second to one every few seconds. Just ran it dry and filled up with 89 octane to see if fuel makes any difference. There is also a third "phenomenon" that doesn't happen very often but its unnerving never the less. The car occasionally will lurch ever so slightly at stop; it's like someone very slowly and lightly rear-ended you without any noise.
 
ch-5lk do you mind describing what do you perceive as rough idle. A lot of people describe the CX-5 idle as "silky smooth" and imperceptible, but then again not everyone is sensitive to those things. I myself consider the idle of my 2014 rough. It not just that though, there are two very distinct and apparently independent "cycles". The first one is very regular vibration that is not always present; still trying to pin it down but have made some definitive observations already. The second is always present and feels as random knocks, like misfiring. Those knocks range from couple per second to one every few seconds. Just ran it dry and filled up with 89 octane to see if fuel makes any difference. There is also a third "phenomenon" that doesn't happen very often but its unnerving never the less. The car occasionally will lurch ever so slightly at stop; it's like someone very slowly and lightly rear-ended you without any noise.

well the roughness is very hard to describe. I felt is only few time in the cabin when the A/C was turned off. The main issue I had was high fuel consumption and reduced pulling power. The rough idle/engine miss was pointed out by the agents and they do not know what to look for now. The other day they said the spark plugs were leaking compression (yellowish insulator - ceramic portion sits outside of the engine) and got all of them replaced. then they tried changing ignition coils and few sensors with new ones but the erratic vibration of the engine is still there. The long term fuel trim is about +2.34% and injector pulse with is about 1.4ms after the plug replacement, it was about +8 before with injector pulse with of 1.7ms. The engine load is also about 18%-19% and the RPM range from 685 to 705. I attached some PID waveforms if you can make any use of it.
 

Attachments

  • pids.png
    pids.png
    18.4 KB · Views: 1,089
Will bring an old thread back to life.

2018 CX5 GT AWD (2.5). Rough idle - when stopped at red light, I feel cycles of vibration (like every two seconds), RPM is 645.
They are not strong, just irritating, I feel them with my legs and butt )
Welcome to the club? :) Have you guys fixed your issues?

Thank you.
 
Last edited:
Will bring an old thread back to life.

2018 CX5 GT AWD (2.5). Rough idle - when stopped at red light, I feel cycles of vibration (like every two seconds), RPM is 645.
They are not strong, just irritating, I feel them with my legs and butt )
Welcome to the club? :) Have you guys fixed your issues?

Thank you.

If I am not mistaken, that idle RPM is a bit low. Should be similar to 2.0L SkyActiv engine which is around 700-750rpm.
 
I purchased a new 2014 CX-5 Touring FWD June 21st 2013

Everything was great for the first 13 days. After that, I noticed the car started to shake in idle. So I call the salesman who sold me the car and he told me to bring it in to have it looked at by the service team and brought the car in July 3rd.

Wait was the car purchased in 2013 or 2018?
 
Back