Clunk/tumbling/knocking felt in the pedal when accelerating

[Nagare]

Wondering if anyone might be able to suggest what this is. I've had my X4 hooked up and it doesn't seem to be engine knock based on that.

After a 2 hour each way road trip this weekend, I noticed a weird tumbling or knocking sound that I felt in my gas pedal as well. It was brief and I couldn't figure out what was causing it. Happened again earlier today and seemed like it may have been around 1-2k RPMs in first or second gear. I'm stumped because it was just at low speed starting to accelerate and I can't seem to replicate the issue.

Any ideas? I haven't really noticed any additional noises going over bumps or unsmooth sections of road either.

Sponsored

 

[USMCtoARMY]

Wondering if anyone might be able to suggest what this is. I've had my X4 hooked up and it doesn't seem to be engine knock based on that.

After a 2 hour each way road trip this weekend, I noticed a weird tumbling or knocking sound that I felt in my gas pedal as well. It was brief and I couldn't figure out what was causing it. Happened again earlier today and seemed like it may have been around 1-2k RPMs in first or second gear. I'm stumped because it was just at low speed starting to accelerate and I can't seem to replicate the issue.

Any ideas? I haven't really noticed any additional noises going over bumps or unsmooth sections of road either.

If you can get a recording. Its just a knock and tumble? There isnt any "slip" feeling in the clutch or feeling a loss of "power" right? Did it start just recently after you had your new exhaust welded in?

 

[Nagare]

It felt like something was loose and knocking around to me at first but I couldn't find anything and I haven't noticed any lose of power.

No strange exhaust noises either.

Automatic car btw so can't answer clutch slip.

If I can get it to happen again I'll try and get a video.

 

[Nagare]

https://photos.app.goo.gl/GrEHdKbf2S66GcdK6

Took this on my drive to work today. Sound only happened at the 3:30 mark but can't edit anything until I get home. The other times it happened it was a few times in a row instead of just once like this time. IIRC it was while I was accelerating into the curve of the on ramp. Not sure if this is something engine or suspension related, but figured I'd start in here.

 

[USMCtoARMY]

https://photos.app.goo.gl/GrEHdKbf2S66GcdK6

Took this on my drive to work today. Sound only happened at the 3:30 mark but can't edit anything until I get home. The other times it happened it was a few times in a row instead of just once like this time. IIRC it was while I was accelerating into the curve of the on ramp. Not sure if this is something engine or suspension related, but figured I'd start in here.

It's hard to tell in the video if what I am hearing is what u are...its sounded like a rattle during acceleration. Nothing to do with trans. Is your AC on? Being that it recently showed up after u had work done it's more than likely related to the work.

Is that a premium bezel I see with V6 push start?

 

[Nagare]

3:20 - start accelerating
3:23 - turn signal on
3:27 - bump in road
3:29 - turn signal off
3:30/3:31 - the noise

The background noise you hear on acceleration is exhaust hitting the cat delete pipes, exhaust, and tire noise. When I picked it up around the 4 minute mark was to make sure on where I heard the sound.

AC and radio off.

Yes its a premium bezel, did a Sync 3 swap a few months back now.

 

[cyclonetron]

Do you have a oil catch can? If so I had some rattling going on due to the canister vibrating against a line. I twisted the canister a bit so that it wasn’t touching the line.

 

[Nagare]

No catch can yet.

Got it up in a lift at the exhaust shop with them just to make sure and nothing looks obviously loose it hanging.

Further "testing" around the plaza gets it if I accelerate through left turns. Guy that also drive it said it felt something was pulling to him.

 

[Nagare]

Here's a video with the issue:



5-7 second mark and 53-54 seconds

 

[MidwayJ]

Here's a video with the issue:



5-7 second mark and 53-54 seconds

Weird. It sounds like somebody just dropping something in the interior of your car. It it more likely to happen during hard turns? Could something be shifting from lateral g forces?

 

[Nagare]

Not trying any turns too hard while it's happening that's for sure! Don't want it to really cause a problem that I won't be able to fix as easily.

 

[USMCtoARMY]

Not trying any turns too hard while it's happening that's for sure! Don't want it to really cause a problem that I won't be able to fix as easily.

It's just hard to tell on the video but since your hearing it on turns its got to be in your front suspension, UNLESS its something coming into contact with your frame thats loose and only hits when u turn.

 

[Nagare]

It's just hard to tell on the video but since your hearing it on turns its got to be in your front suspension, UNLESS its something coming into contact with your frame thats loose and only hits when u turn.

I'm happy to report back that it was something a little loose. Exhaust piping was hitting the trans mount. Used a bar to move it a bit further away and tightened up the clamp a little bit (got a half turn) and it seems to be gone for now.

 

[USMCtoARMY]

I'm happy to report back that it was something a little loose. Exhaust piping was hitting the trans mount. Used a bar to move it a bit further away and tightened up the clamp a little bit (got a half turn) and it seems to be gone for now.

Lol, I told ya I thought it was something from you having exhaust work! Glad its squared away and the stress is gone bro.

Sponsored