CX-5 Jerks back and forth when warmed up and pushed hard

N

nocrush

CX-5 GT 18", Stinger GT2 21", Grand Vitara 08"
Imagine a case when I'm cruising 60 mph and suddenly press gas pedal harder - the trans drops 1-2 gears and car starts to jerking back and forth while slowly getting more and more speed. You can stop it by releasing the gas pedal. This may happen when you are driving uphill on cruise and car adds more power to the engine - the car starts shaking back and forth.

The issue, happens only on hot/warmed vehicle, like after 10 minutes of active driving. On cold vehicle this never happens. It doesn't matter automatic or manual trans mode is used. It doesn't matter what gear you are using. The very violent shaking happens between 2-3k rpm. Before that rpm range or after it may be less noticable.

It's very similar to how an unexpected driver engages clutch on manual transmission and starts moving - too quickly released clutch pedal makes the car to jerk. Same here.

My guess was transmission fluid - "changed" it twice by draining what i could and adding new one, OEM. Didn't help.

I don't have any DTC, any errors, everything behaves normally.

Does anyone experienced this issue ? Any guesses what it could be ?

Thanks
 
My guess is a fuel issue. Did you fuel up recently ? Perhaps a tank of poor quality/contaminated fuel.

Fuel up with some highest octane you can find (Sunoco ultra94) premium 93 etc. and see how that does.

What model year and motor is your car? How many miles?

If fresh gas doesn't help, next I would use a scan tool such as FORscan to figure what's happening.
 
Model year and mileage? As suggested above, I’d want to check for codes. If no codes I’d want to either reset the transmission software to relearn or have it updated.
 
It's 2018 CX-5 2.5L gas, not turbo, AWD, 95k miles, spark plugs changed last time at 90k, the gas/fuel filter in the tank is going to be changed once new arrives in couple days.
Fuel - it's Costco and Kroger, 87. The car has this issue on both brands.
And I'm having this issue for 6 months or so. It's not one-time bad fuel problem.

But I don't think it's a gas filter from the tank because it would kind of restrict the upper limit of amount of gas going to the chambers. Like, the mixture would be lean, and i don't see (i may be wrong, of course) how lean mixture can cause jerks.

The same for fuel injectors: if they restrict some flow then they should do that for whole range of power, not just when i push engine to it's limit and not when it's hot.

And remember, this doesn't not happen when car is cold.

Thanks

Update: not 6 months, less, like 2.
 
Last edited:
HyFlyer said:
My guess is a fuel issue. Did you fuel up recently ? Perhaps a tank of poor quality/contaminated fuel.

Fuel up with some highest octane you can find (Sunoco ultra94) premium 93 etc. and see how that does.

What model year and motor is your car? How many miles?

If fresh gas doesn't help, next I would use a scan tool such as FORscan to figure what's happening.
Click to expand...
I scanned it with autel 508 - didn't find anything. The car is clean out of any codes.
 
A lean mixture can cause jerking because there may not be enough fuel in the cylinders to fire. And it may be inconsistent as well.
Even worse, lean fuel mixture could cause more damage (detonation, blown head gasket...etc)
If it was a plugged fuel filter, it would more likely happen under high load/rpm because that's when you need the most fuel.

Same goes for injectors. If they are partially plugged, they might work fine under light engine loads, but cause issues at high loads/rpm.

But, the fact that it doesn't happen cold is the curveball.
 
I don’t think I’ve read any instances of a user here replacing their fuel filter either. It’s one of the few parts on the CX-5 that I’d consider a lifetime part.

Only cheap or free thing to try would be based off of Hylux’s observation. The transmission could be doing something funky once the ATF is warmed up. “Violent” sounds like something rapidly engaging and disengaging, not an ebb and flow like fuel flow to me. Also sounds like the behavior is consistent.

How does once manually reset the transmission learning procedure anyway? I know with other vehicles it can be achieved by removing the battery for like 30 minutes but I honestly can’t remember how to do it on a CX-5.
 
ruthrj said:
I don’t think I’ve read any instances of a user here replacing their fuel filter either. It’s one of the few parts on the CX-5 that I’d consider a lifetime part.

Only cheap or free thing to try would be based off of Hylux’s observation. The transmission could be doing something funky once the ATF is warmed up. “Violent” sounds like something rapidly engaging and disengaging, not an ebb and flow like fuel flow to me. Also sounds like the behavior is consistent.

How does once manually reset the transmission learning procedure anyway? I know with other vehicles it can be achieved by removing the battery for like 30 minutes but I honestly can’t remember how to do it on a CX-5.
Click to expand...
I don't know neither, but I will find out how to do that, and will let you guys know about the outcome. On my kia stinger it helped to make shifting better, I hope mazda has some user-friendly procedure which I can do as well. Don't wanna look for a dealer-level equipment again ...
 
@sinistriel@ has posted the procedure in a thread before. Maybe in the last couple of months.

EDIT: Found it. There's a video as well.

Brand New 2022 CX-5 Transmission Problems? Updated!

I suppose I need to add a bit here. 2023 Cx-5 NA. Ever since it was new and when pulling out first thing in the morning with everything cold, the 2-3 shift would flare, then hit 3rd hard. It would do this for the first 2-3 stop signs getting out of the neighborhood, then shift perfectly until...
mazdas247.com mazdas247.com
 
thanks for much for the link ! Saved my time :) appreciate ti.

Btw, i know it sounds silly, but can it be an issue with torque converter ? Maybe I don't know something about it...
 
Video could help, maybe of the tachometer during the abnormal behavior. I’d be interested to see if the rpm’s are fluctuating during the shaking, or if it’s staying constant while bucking.
 
ruthrj said:
Video could help, maybe of the tachometer during the abnormal behavior. I’d be interested to see if the rpm’s are fluctuating during the shaking, or if it’s staying constant while bucking.
Click to expand...
indeed, rpm on dash panel are fluctuating, but barely noticeable.
 
nocrush said:
It's 2018 CX-5 2.5L gas, not turbo
Click to expand...
The plot thickens ... Adds 1st year CD into the equation of possibilities

nocrush said:
95k miles, spark plugs changed last time at 90k,
Click to expand...
So, tell us more about the relationship of new spark plugs and this bucking problem developing. Did the problem occur before or after changing spark plugs?

nocrush said:
And I'm having this issue for 6 months or so. It's not one-time bad fuel problem.
Click to expand...
Lol, okay the way I read your original post felt like this was something new that just happened not something going on for 6 months.

nocrush said:
And remember, this doesn't not happen when car is cold.
Click to expand...
Thoughts of differences when the engine is cold vs normal temp ...

the PCM enriches the mixture with more fuel until it's warmed up.

CD may not operate until up to temperature? (Idunno? Just asking those who know more about that system)

Crack in a sparkplug ceramic insulator or coil issue only when hot

Odd that the car feels itself happy enough to not throw a code about something with such behavior. Could the Autel scanner not pickup Mazda specific stuff?
 
Thanks for inputs, here are my responses:
* pardon my English, it's not my first language.
* CD - sorry, but what is CD ?
* spark plugs - i wrote it just for case, because I've talked about this problem to many people and I heard so many opinions. The most common are spark plugs and injectors. And a gas quality, of course. So these are not my reasons of issue.
* did the problem occur before park plugs change ? No, of course no, I don't remember when it started, because apparently, it was too little to notice, but with time it developed.
* I doubt a crack in spark plugs insulator because the issue happens only when I press gas pedal hard. The more warmer the engine/trans/internals, the less hard you need to press the pedal to get this issue.
* car feels itself happy enough - may be indication of mechanical issue, like a clutch pack or something.
* autel not the best - could be, but I've tried other scanners as well, none showed any codes.
 
You'll probably need to see what is going on with current data. On that model of Autel will it read the TCM? There is some live data you can watch to see what is happening. You'll want to graph engine rpm, turbine/input shaft speed and TCC operation when this is happening. Often transmission issues will not set codes. I took a short video of a failed Skyactiv we're working on right now that has no codes in the engine or the transmission. 2017 CX-5 broken transmission
 
CD is cylinder deactivation. 2018 models had an issue with a hydraulic lifter arm falling off due to faulty programming. A software fix was released to prevent the arm from falling off. Symptoms of that were reduced power when applying throttle, like the car not really doing anything when slamming the gas to pass somebody.

Incompatible spark plugs could cause an issue. Folks are pretty careful here to get the Mazda OEM plugs or the NGK part number equivalent.
 
https://www.ebay.com (commissions earned) - these spark plugs were installed when car had 85k miles on May 19 this year.
hydraulic lifter arm falling off due to faulty programming ? ... could be, but it doesn't have a correlation with cold/warm car, right ?

I can graph some live data from sensors, will try to do that soon.
 
Please log in or register to reply here.

Similar threads

M
Thudding, Inconsistent Idle Rev, Musty Wet Air Smell (2016 CX-5)
Replies
3
Views
1K
weitau
W
J
2019 CX-5 2.0L Petrol: Auto Transmission jerky…Help
Replies
11
Views
1K
ceric
ceric
J
CX-5 Turbo warm up time?
3 4 5
Replies
81
Views
6K
jadmt
jadmt

Latest posts

Back