Probably not related, but to me the auto stop/start crap makes the car seem to hesitate from a stop. I try to remember to turn that "feature" off but sometimes I forget. It could seem like a shudder but it would be during acceleration from a stop.

 

Wanted to reply with an update. Although transmission was initially ruled out, today we learned that the transmission is trashed. We were hoping a flush would fix, but it's too far gone.

 

I bought a new 2019 Camry that had this exact problem which led me to trade for the XT4. After letting Toyota play games with me over 3 repair attempts, a senior mechanic pulled me aside and told me off the record that all 2019 Camrys and Highlanders had the shuddering problem and it is NOT repairable. Toyota refuses to acknowledge it as a faulty design and they're doing fuel pumps, transmission resets etc to pacify owners. The problem according to the technician is the marriage of the 8 speed transmission and hi output smaller engine. The car does not recognize which gear to select when rolling around a turn and the driver then pressing the accelerator. You have to punch the pedal to get the transmission and engine in sync and THEN the car finally takes off-but no soft departures! If you don't punch it, it can get pretty sluggish to the point of jarring your head back and forth.
I'm finding the same issue seems to exist in my XT4. It really lunges at times and jerks at initial acceleration. I've been practicing a smoother depression of the pedal by pushing my foot against the engine housing for better stability and it helps but isn't always effective. When going over large speed bumps, the car downshifts too far and you cannot glide back into a sufficient throttle to keep the vehicle's momentum. The downshift that the speedbumps cause make the engine roar and in that low of a gear, the car won't get out of its own way. The more I focus on micro-controlling the accelerator, I find things smooth out a little. I've had it 3 yrs and it still gets pretty independent at times. It is what it is. The performance and enjoyment I get from this vehicle far outweighs the occasional Ford Pinto impressions.

 

I've also found these turbo rockets to be extremely picky about fuel. Say goodbye to 93 Octane at 7/11 and Racetrack. Shell Premium DOES make a difference and you'll feel it.

 

1000%, and a lot of manufacturers (GM, Toyota, BMW, etc) have a significant amount of bulletins that they've released over the years recommending Top Tier Gasolines to maintain longevity and performance in their engines; further, these engines require 93 octane (brand and octane are two distinctly different things), and both brand & octane will affect how these engines perform.

 

I have a 2024 xt4 that I purchased in December 2023. Almost immediately the shudder started. It slowly became worse and worse. After 3 trips to the dealership ( and they were very nice) it was determined I needed a new transmission. I had less than 5K miles on it.
Recently I went to start my car and the starter just kept trying to start with no turn over. After a tow to the dealership it was determined I needed a new fuel pump. I have 17K miles on it. Not only could they not locate one to replace it after two months, they put a used one in and I will have to go back when/if they get a new one in to replace it.
I asked for a buy back. GM determined that was not an option. I am one UNHAPPY Cadillac owner. I moved from being a life long Honda owner with no issues to wondering what's going to happen next. I am so disappointed.

 

I have a 2024 xt4 that I purchased in December 2023. Almost immediately the shudder started. It slowly became worse and worse. After 3 trips to the dealership ( and they were very nice) it was determined I needed a new transmission. I had less than 5K miles on it.
Recently I went to start my car and the starter just kept trying to start with no turn over. After a tow to the dealership it was determined I needed a new fuel pump. I have 17K miles on it. Not only could they not locate one to replace it after two months, they put a used one in and I will have to go back when/if they get a new one in to replace it.
I asked for a buy back. GM determined that was not an option. I am one UNHAPPY Cadillac owner. I moved from being a life long Honda owner with no issues to wondering what's going to happen next. I am so disappointed.

If you bought this car new, you should call an attorney that specializes in lemon law cases. Of course GM determined it was not an option-they will never allow an owner to exercise that solution without force. I'm shocked they put a used part on your car. I'm not certain, but I would think their factory warranty would require new oem parts replacement. Some manufacturers warranties go as far as to say replacing parts with anything other than new oem parts may void the warranty. This should be covered in the warranty insert in your manual pack. Fight back! Don't let them steamroll you. I went through this at Toyota with a fuel pump. Fuel pump ended up not even being the problem. It was the inappropriate pairing of the engine and transmission. They are not compatible.

 

Challenges with this shuddering concern you are experiencing within your 2019 Cadillac XT4 is a matter we would like to learn more about. Please know, safety is our utmost priority and we strive to bring the best resolutions forward for our Cadillac customers. As we understand you have found ways to smooth our this shudder and acceleration, it is our goal to restore your confidence in the vehicle. From here, do send us an email to socialmedia@gm.com with the addition of your Username and Forum name listed in the subject line. This information will allow us to properly proceed.

Challenges with this shuddering concern you are experiencing within your 2019 Cadillac XT4 is a matter we would like to learn more about. Please know, safety is our utmost priority and we strive to bring the best resolutions forward for our Cadillac customers. As we understand you have found ways to smooth our this shudder and acceleration, it is our goal to restore your confidence in the vehicle. From here, do send us an email to socialmedia@gm.com with the addition of your Username and Forum name listed in the subject line. This information will allow us to properly proceed.

JFMCO first they replaced the catalytic converter. This did nothing. Then they replaced the transmission. It is no longer shuddering and making noises however the smooth transmission is not always smooth. I did have the dealership drive it and they said what it is doing is just trying to find the gear when accelerating.