Intermittent Drivetrain Vibration Help

[domoarigato]

Hey all,

I've noticed a very slight intermittent vibration that feels like its coming from the floorpan somewhere while driving. Steering wheel feels fine. Since I'm new to this platform, I'm hoping there are some common areas you guys can recommend that I check. It doesn't happen all the time, and I can't replicate it.

The tires are brand new Goodyear RS-A's and I plan on getting them high speed balanced and roadforced. But from my experience a tire vibration feels slightly different than what I'm experiencing but I will not rule it out.

Symptoms:
- At 65-70 mph I will feel this vibration, if I give it some gas it will go away.
- At low speeds I will feel this vibration, again goes away if I give it gas.

Possibilities:
- Tires need balancing?
- Worn driveshaft? Is this common on these vehicles?
- Worn engine / trans mounts? I believe I saw that the trans mount was replaced earlier in the maintenance records I got when I purchased the vehicle.
- I've also read that it could be AFM kicking on / off, but I didnt think AFM was on at low RPM / not in 6th gear.

Anything else I might be missing / unwaware of?

Thanks!

 

[Plimbob]

Jake,

This may be a long shot but do a quick check of your front wheel bearings.

 

[2011SSVHOE]

Mine does the same I thought it is the AFM also

 

[American Dream]

Possibly the engine changing from V8 to a V4 ?? Mine vibrates in V4 mode and it's annoying. Bullydog has an item that will defeat the V4 mode and make it stay in V8. The dash info center has an option to watch which mode the engine is in.

 

[domoarigato]

Jake,

This may be a long shot but do a quick check of your front wheel bearings.

Thanks, I will check those too when I can get it on a lift.

Mine does the same I thought it is the AFM also

Possibly the engine changing from V8 to a V4 ?? Mine vibrates in V4 mode and it's annoying. Bullydog has an item that will defeat the V4 mode and make it stay in V8. The dash info center has an option to watch which mode the engine is in.

I only reason I dont think its AFM, is it happens sometimes at low speeds. Not ruling this one out though.

Thank you all for the input.

I am also going to check the rear driveshaft / driveshaft u-joints for play.

 

[American Dream]

Change your dash info setting to see your real time fuel mileage. It shows right above that if you are running V8 or V4. That's the only way I made the connection on the vibration. The AFM software activates at light load and little throttle variation. The reason the vibration disappears when you give it throttle is because the engine returns to V8 mode.
Change your dash info and watch it vary from 8 to 4. I garauntee the vibration is from AFM. Don't waste your money until you verify that is NOT causing it.

 

[2011SSVHOE]

yep that what mine does. I didn't notice it before I bought the car, but about a week later I noticed it going around traffic circles and at light or no load conditions. just wondering if it will get any worse.?