2021 CX-9 - knocking noise when turning from a dead stop

[JC707]

Good afternoon folks. Have my first issue with our CX-9 and wanted to document it for any future owners that may have same issue.

Our CX-9 is brand new 2021 GT and has 300 miles now. My wife has been driving it mostly but I took it out today for some errands. We've been babying it going pretty easy and today heard a weird clunking/knocking noise from the engine area/front of vehicle for the first time which I spent the next 30 minutes replicating the issue to be sure. And it's easily replicated so dealer shouldn't give me crap lol.

It happens after coming to a complete stop, then turning right or left and hitting gas tho you don't have to mash gas just give it a bit to put a bit of strain on system. I also noticed it when stopped on a hill and having to press the gas a bit to get going up the hill.

My first thought was either engine mounts, bushings, or axle/suspension parts. I searched here and found some possibly fixes of dealer tightening chassis bolts, cowl bolts, and even replacing strut towers.

I am heading home to fully inspect everything and will report back. I am guessing it's a loose bolt somewhere in suspension. My first oil change is free at 5k miles so may wait until then to bring it to dealer.

Thanks!

 

[JC707]

Edited my post about cowl bolts question, found the TSB someone posted. I am 99% sure it's coming from suspension as I can sort of feel the clunking noise if that makes sense. But I will definitely check the cowl bolts to be sure.

 

[JC707]

Update: checked strut tower bolts, cowl bolts, etc and didn't find anything. I took it for another drive and this time hit gas a bit harder (not brake launching type hard tho) and it seems the harder you press pedal to drive off the louder it is, really loud to be honest. Happens only when accelerating from a dead stop either turning left/right or going forward.

Has to be an engine mount or something with suspension. Really bummed our vehicle has 300 miles on it and having this issue but sh*t happens. Debating on waiting until 1st oil change or bringing it in, I have a mazda dealer 5 minutes from me but was thinking it's better to bring it to the purchasing dealer (40 minute drive) but not sure it matters...

 

[Silly Wabbit]

Sometimes it's very hard to narrow the source of sound from inside the cabin. Have you try to stand outside and have your wife replicate it? At least you might be able to tell if it's driver or passenger side.

 

[JC707]

Sometimes it's very hard to narrow the source of sound from inside the cabin. Have you try to stand outside and have your wife replicate it? At least you might be able to tell if it's driver or passenger side.

Thats a great idea. She is at work but tomorrow will try for sure and report back.

 

[dougal]

Any news on what it is?

 

[JC707]

Update:

Haven't been able to go to dealership but have been doing more testing while around town doing errands.

The day I first noticed it, it was a warmer outside air temp, pretty warm actually.

Last weekend it was cool and cloudy and the knock noise was harder to replicate. The noise happened only on an incline as well. I went up a longer incline and started at the bottom, it made a slight knocking noise for the first attempt, then every attempt to replicate the issue after the first attempt I wasn't able to do so until I got to the top and could no longer try.

To replicate I would have to turn around and drive around then make my way back to the incline hill and do the process over again. Everytime, noise only on first attempt then going up the hill trying to make noise, got nothing.

Besides this, driving around there is no hard shifting or weird noises, it drives beautifully. I will most likely wait until my 1st oil change and go from there.

 

[JC707]

After my 600 mile break in, I will try some rolling attempts by stepping on gas and releasing quick to really put some strain on engine/transmission/suspension parts and see if it makes the noise as I am curious about that.

 

[JC707]

I found this post by a member which I found interesting and informative. I am wondering if it's just the behavior of the CX9? Other than a small occasional knock noise, our CX9 drives perfect and no hard shifts etc.

 

[dougal]

I found this post by a member which I found interesting and informative. I am wondering if it's just the behavior of the CX9? Other than a small occasional knock noise, our CX9 drives perfect and no hard shifts etc.

Really kind of hard to read but I will say that small noises tend to amplify in the cabin. I had a weird noise that came from my rear end (that sounds wrong!) whenever I stopped hard or accelerated hard. Turned out to be lug nut key lock in the trunk "hatch" area that was moving around at times. I swore it came from somewhere else but that was it. I can even hear my eyeglasses moving around in the holder when I wear my sunglasses!

 

[JC707]

Sorry I just checked and it is tiny on the screen shot. I am copying and pasting below:


"The Mazda CX series of vehicles that are "SkyActive-Drive" and AWD have the most rotational play in the front and rear drive shaft than I have seen to date. I have personally experienced a slight "knock" coming from these drive train components during the break-in period of my new 2018 CX-9 Signature. I specify "during the break-in period" because over time the knock has become less noticeable. However, it is still present and I notice it becomes more pronounced with higher ambient OAT. I've come to the conclusion that at or below 1,200 rpm, either the clutch and/or torque converter are not as well sync'd as they could be. Or, maybe this is as good as Mazda can make it given the new torque converter design they implemented into the CX-9 (not sure of the Mazda 6 shares the same converter).

The CX-9's transmission is supposed to be a hybrid design offering the best qualities found in a conventional automatic and manual or dual clutch transmission to provide on-demand torque with faster on-set and reduced lag. I applaud the effort by Mazda (I really do). However, it is my belief that one of the drawbacks of their attempt comes with a missing level of refinement in the smoothness of the transmission at or below 1,200 rpm in a heavier vehicle - where sometimes the engine output is not sync'd adequately throughout the rest of the drive-train to prevent this "clumsy" kind of transference of power down to the wheels at near idle RPM. I doubt this is an issue with the Mazda 6, because of its lower curb weight.

I think this has to do with the weight of the vehicle combined with the new torque converter design. On a full tank of fuel, this "lugging" (what you call knock) is dampened to the point of almost being imperceptible. When the vehicle is lighter, the low RPM lugging comes back on throttle-up while rolling and from a low RPM condition. I don't think there is anything "broken" here. I just think this is a "design characteristic" of the CX-9's drive-train in particular depending on how your CX-9 made it through its break-in period (you may have more or less lugging/knocking) and was ultimately set-into its mechanical tolerances (every new vehicle will vary slightly/fractionally after set-in).

In short, the vehicle is trying to give you on-demand access to greater torque at a faster rate pf on-set and from a lower RPM. That's the important part to remember - from a lower RPM. That's the primary job of a transmission - to efficiently manage and direct engine output to the wheels (ultimately). At 4,300 pounds howerver, that whole process needs to be as smooth as possible throughout the entire RPM band.

I think the problem is in the Lock-Up of the Torque Converter, quite honestly. Mazda, designed the new torque converter to have an extended lock-up time which extends the time the engine rotation is directly linked to transmission rotation - specifically from lower speeds - which means from lower RPM. They claim lock-up ratio increase of 30% over the previous torque converter design used in their vehicles. When they did this, they also were forced to re-design their Clutch to include multiple discs and a larger vibration damper spring.

I like it. It's just not as "refined" as it could be and that's why we are hearing the "lug"/"knock" at our door - or under the vehicle to be more precise. I'm going to be talking with Mazda soon about my paint. When I do, I'm also going to engage them about the reason behind so much rotational play in the front and rear drive shafts - while all four drive axles have precious little rotational variance. There has to be a engineering reason behind so much play in the drives"

 

[ionlythink]

Good afternoon folks. Have my first issue with our CX-9 and wanted to document it for any future owners that may have same issue.

Our CX-9 is brand new 2021 GT and has 300 miles now. My wife has been driving it mostly but I took it out today for some errands. We've been babying it going pretty easy and today heard a weird clunking/knocking noise from the engine area/front of vehicle for the first time which I spent the next 30 minutes replicating the issue to be sure. And it's easily replicated so dealer shouldn't give me crap lol.

It happens after coming to a complete stop, then turning right or left and hitting gas tho you don't have to mash gas just give it a bit to put a bit of strain on system. I also noticed it when stopped on a hill and having to press the gas a bit to get going up the hill.

My first thought was either engine mounts, bushings, or axle/suspension parts. I searched here and found some possibly fixes of dealer tightening chassis bolts, cowl bolts, and even replacing strut towers.

I am heading home to fully inspect everything and will report back. I am guessing it's a loose bolt somewhere in suspension. My first oil change is free at 5k miles so may wait until then to bring it to dealer.

Thanks!

Hi, I'm having the same issue. I'm driving a 2019 CX-9 with 50k miles. The issue just started a couple months ago and is very intermittent. The sound is a bang almost as if the drive shaft is smacking into place a second late... I brought the car to the dealer, they drove it for 11 miles and weren't able to replicate the problem. They offered that I can take a tech for a test drive and try to replicate it myself. In the meantime, we're you able to figure out what it was? Any help would be greatly appreciated. I want to purchase the car (post lease) but im afraid to spend 20k if the issue is serious.