Thanks for your reply! Well I have OEM plugs changed at 70K miles and that didn't change anything. I understand your doubts, but if it's an engine problem, wouldn't it be irrelevant to which gear you are in? I could be wrong though.It is possibly "bucking"? Usually it is the car "missing". Proper ignition of the mixture is not occurring. Usually happens when cold when you need a richer mixture. Weak spark? Tired spark plugs? Lousy spray pattern for direct-injectors?
Doubt it's transaxle-related...
Thanks for the input. Sounds like I need more testing on this issue: I could try accelerating harder in 3rd gear and I should feel the buck if there is one? I'll come back with more info.Good points... Couple of additional points... In first gear the load on the engine is less, mebe, with less of a propensity to buck. 3rd gear and above .. is it possible that it is bucking, but in the higher gears you just can't feel it nearly as much? I have a manual Camry that bucks in second when cold, but not in first or third and above...
This has not much to do with temperature unless if very hot like 90F or 32C+, there's a chance that this won't happen. (I lived in Georgia and moved to California, this issue has been happening about half a year now). I know the car revs higher at cold starts. But that shouldn't be the problem because the higher rev only happens in park. Once you shifts to drive, the idle revs get back to normal (at least for AT).Do you live in a state that is normally pretty warm and it happens to be unusually cold right now?
These cars have a software routine to assist with warmup. The computer tweaks the engine rpms a little higher. This can result in a bit of bucking. It's usually only noticable with the manual transmission, but it wouldn't surprise me if it can happen in the auto.
Easy way to tell, when you start your car what is the engine speed at idle?
OK but after TCC locks up, there shouldn't be jerk or bucks right? It makes sense if the locking process creates a jerk, but I can feel exactly two jerks, consecutively, about half second apart during an acceleration. They are also quite strong, to the point that one can easily tell this is abnormal.Well, especially because the A/T, in effect, behaves as an M/T once the torque converter locks up... which is very quickly after startup... and once into second, TCC is locked up pretty well soon as the first to second shift is made...
Great, now what is the engine rpms at idle?This has not much to do with temperature unless if very hot like 90F or 32C+, there's a chance that this won't happen. (I lived in Georgia and moved to California, this issue has been happening about half a year now). I know the car revs higher at cold starts. But that shouldn't be the problem because the higher rev only happens in park. Once you shifts to drive, the idle revs get back to normal (at least for AT).
Glad to hear that! Did you do a transmission oil flush and did you change the filter back then? I did a drain and fill (used about 4.5 quarts) and it didn't help.I had this issue with mine (same year and model) at around 90,000 miles and it seemed to remedy after replacing my transmission fluid. Although it claims to be a “lifetime fluid,” it was really in need of replacement at the time.
I also had the same issue with my previous vehicle, albeit not a Mazda, and it was corrected after preforming a transmission software update through the ODB port.
That's what I did too. I didn't feel comfortable removing the fluid pan to replace the filter, or otherwise, I would have done that too. I probably will next time though. I'm sorry that didn't work for you! I do belive that a software update could resolve the problem though. You could take it to a mechanic rather than a dealer for this as well.Glad to hear that! Did you do a transmission oil flush and did you change the filter back then? I did a drain and fill (used about 4.5 quarts) and it didn't help.
I thought I replied to you but apparently not. The idle rev in drive is ~700rpm. In neutral it will be higher depending on how warmed up the car is.Great, now what is the engine rpms at idle?
What you're not understanding here is the relationship between engine rpm and the transmission. When you put it into gear, yes the engine speed will fall as the transmission now dictates the engine speed. However under the conditions I described, the ECU is still putting more fuel in the engine and bumping up the engine power to assist with warmup.
So I'll ask again. What is the engine speed at idle when this happens?
I am in literally the exact same situation as you, same problem, same car. Did you ever fix the issue or did it get worse or anything?Hey, have you resolved the issue yet? I have the exact same thing happening to my 2016 Mazda 3 2.0 6AT. When cold, I get a jolt in 2nd gear that happens once or twice. It stops once the car is warmed up. It started happening at around 60k miles and hasn't gotten any worse or better since then (at 80k miles now). I have done two drain and fills with OEM ATF. I even dropped the pan and cleaned up everything and replaced the filter. No change, does the same thing. Throttle body is cleaned up, new filter dropped in. Also replaced the spark plugs and replaced the purge solenoid since there was a small leak in the evap. No change after that fix either.
