2016 Limited violent vibration on acceleration

[Aydlan]

Hello,
Im hoping someone can give me some insight as to what the problem is. My wife came in and told me that her car was making a sound like something was stuck in the tire. I took it around the block and its definitely more serious than that. When easing out everything is fine but if I give it a little punch, their is this fast/violent vibration coming from under the car. Its only when you accelerate quickly or put it under load by going up a hill. I switched it over to snow mode and because of the ease of the acceleration curve i couldn't get it to vibrate. It also doesn't have any issues driving, just when accelerating.

I have been looking all over the internet and no one seems to have noted my exact problem or at least not how I would describe it. Some are saying its the engine/transmission dampener while other say its the drive shaft. The PTO was just replaced on this about 2k miles ago.

Thanks in advance for any help.

 

[mguy13sport]

Can you look under the car? See if the driveshaft is wobbling

 

[peterk9]

Welcome to the Forum Aydlan,
As I was reading your post I was thinking PTU but then read that it was replaced recently. Perhaps the driveshaft should be checked first and see what the result is.

Peter

 

[94Eddie]

Check the motor mounts too. Try putting it in drive, applying the brake so the car won't move and at the same time depressing the accelerator some. Have someone watch, or video, the engine to see if it moves excessively or if you can here and locate any noises.

 

[Crates]

Driveshaft would be my first guess.

 

[Aydlan]

Thanks for the responses.

An update to this - put a brand new driveshaft in assuming that had to be the problem. Still has a vibration when accelerating but its not as violent as before. We are thinking that this PTU is bad because when putting it in gear and doing a slight brake torque, you can start to hear it rattling. We also heard a slight hum noise while it was sitting in drive. My dad is gonna jump back under it tonight and look things over. He initially said a PTU but we of course ruled that out seeing that its only a few months old. We also thought maybe a motor mount, but there is no hard shifting or anything. Driving it to my dads house I had no problems and got up to about 60. It was only when accelerated hard in front of his house that the noise came back.

Anyone have any other suggestions we should look at before I take this back to the shop that put the PTU in?

 

[ProjectSHO89]

Why was the PTU replaced?

Was it for this issue or did this issue occur AFTER the PTU replacement?

 

[Odrapnew]

If it’s making noise when you brake torque it, I don’t think that’s the PTU. Since you are stationary, the PTU shouldn’t be moving unless it’s damaged.

I suppose it could be mounts as someone else suggested. If the engine/transmission is moving enough, maybe there’s a metal/metal contact that is transmitting more driveline vibes into the chassis.

To me that sounds like mounts or something in the engine or transmission. Even brake torquing the engine leads me to believe it’s up near the torque converter/flexplate (or in the engine).

 

[Aydlan]

The PTU was replaced because it went bad. This issue is after its replacement, about 2k miles after. Ill focus on the mounts and see if that could be the issue. Just hoping its not an internal issue in the tranny or something.

Thanks again

 

[mguy13sport]

I just want to clarify all drivetrain components including the PTU will be under load during a brake stand (gas + brake) while in gear even while stationary. I would not be ruling out the PTU. Does anything happen in reverse like same noises etc if you give it some gas?

If your old driveshaft was bent its possible that it has potentially damaged the replacement PTU.

Is this a reman/rebuilt or used PTU replacement?

 

[Odrapnew]

I just want to clarify all drivetrain components including the PTU will be under load during a brake stand (gas + brake) while in gear even while stationary. I would not be ruling out the PTU. Does anything happen in reverse like same noises etc if you give it some gas?

If your old driveshaft was bent its possible that it has potentially damaged the replacement PTU.

Is this a reman/rebuilt or used PTU replacement?

That's true.

@Aydlan - Can you clarify what you mean by rattling when doing brake torque? What kind of rattling? Any video?

 

[ExplorerOverland]

The PTU was replaced because it went bad. This issue is after its replacement, about 2k miles after. Ill focus on the mounts and see if that could be the issue. Just hoping its not an internal issue in the tranny or something.

Thanks again

Did you find a resolution? Having what seems to be this exact issue. I removed the driveshaft and it got worse. It feels like it’s front passenger side on my car.

 

[Aydlan]

Did you find a resolution? Having what seems to be this exact issue. I removed the driveshaft and it got worse. It feels like it’s front passenger side on my car.

The lower transmission mount was missing the bolt. When they replaced the PTU I guess they forgot to tighten it and it eventually came out. Replaced that and it was back to normal