2014 50i Msport vibration and shudder on accel and decel

[smashe]

61k Miles, Out of nowhere my car is getting a vibration on acceleration only and somewhat of a shudder when I let the throttle off. The vibration only happens around 1500-2000 rpms around 35-40mph then goes away. Just got tires mounted and balanced, it's not a rotational issue, its only under load when I'm on the throttle. WOT pulls are fine. Any ideas? This is definitely driveline related, the vibration is definitely coming from the rear end unless maybe its resonating from the driveshaft.

[201]

Have you checked for fault codes? Highly unlikely but check your wheel lugs to see if they are tighten within spec as you never know with these tire shops. From my experience the most common cause of your symptoms is cv joint related but at this point all you're going to get are guesses.

[Hellrot]

Took mine in a couple times for something similar and it ended up being a bad coil. Dealership didn't do anything until the car eventually went into limp mode.

[Sophisticated Redneck]

Originally Posted by smashe

61k Miles, Out of nowhere my car is getting a vibration on acceleration only and somewhat of a shudder when I let the throttle off. The vibration only happens around 1500-2000 rpms around 35-40mph then goes away. Just got tires mounted and balanced, it's not a rotational issue, its only under load when I'm on the throttle. WOT pulls are fine. Any ideas? This is definitely driveline related, the vibration is definitely coming from the rear end unless maybe its resonating from the driveshaft.

Try this: when it starts to vibrate, downshift it while keeping your speed the same. This will help determine if the vibration is independent of engine rpm. If it is then definitely rearend/drive shaft, etc. If it is dependent on engine rpm, then could be failing I injector/coil

[smashe]

Originally Posted by Sophisticated Redneck

Try this: when it starts to vibrate, downshift it while keeping your speed the same. This will help determine if the vibration is independent of engine rpm. If it is then definitely rearend/drive shaft, etc. If it is dependent on engine rpm, then could be failing I injector/coil

That's not a bad idea. I'll give it a try and report back, I'll scan the car tonight for codes as well. Just for kicks I looked up a new CV shaft......over $1000 lol...ridiculous.

[smashe]

Scanned the car with my snap on scanner, no codes came up. And tried doing the downshift thing at same speed, no vibration only on accel. Now when cruising around 5mph in traffic if I blip the throttle real quick the transmission will briefly shudder upon lifting off the throttle. The shudder is more annoying than the vibration. I need to get underneath and start inspecting components. @62k miles I'm probably due for diff and trans flushes, I dont have maintenance records from the previous owner so no clue as to when it was done last.