Jump to content

Vibration in Floorboard, Not Speed/Tire Related

TxTruckMan

By TxTruckMan
in Troubleshooting & Recalls

Recommended Posts

DRS 95 Silverado Enthusiast

DRS 95 Silverado

Posted
Posted

I have managed to get rid of about 90% of the exhaust resonance vibration in the floorboard and accelerator pedal.

This is what I have done so far;

Installed the Range V8 which helped some by keeping the engine out of V4 mode.

I Clamped weights to the pipe after the muffler but before the resonator which made a big difference (see pics below). This was done mainly to determine which area of the exhaust was generating the resonance.

I think the bent portion of the pipe going over the rear axle in the spare tire area is causing most of the resonance. The resonator right before the exhaust outlet may have something to do with it as well, but it's definitely being generated after the muffler.

 

Next step will be to install a helmholtz resonator like the one in the pic below. I will make it adjustable until I determine the correct length needed to cancel out the resonance, then it will become permanent.

 

I DID NOT WEIGH the WEIGHTS before mounting.

Thats where my sound seems to be coming from. Mines not too bad but you can hear and feel it come and go a little. I also wonder about the flapper valve. Do you think it has anything to to with it? You ought to take to dealer and let them drive it, then take all the weights of and drive it again. If it's the exhaust in some of these trucks causing problems it should be easy for GM to come up with a solution. I don't think everyone is having the same type of noise/vibration.

  • Replies 95
  • Created
  • Last Reply
14SLTZ71 Enthusiast

14SLTZ71

Posted
Posted

Thats where my sound seems to be coming from. Mines not too bad but you can hear and feel it come and go a little. I also wonder about the flapper valve. Do you think it has anything to to with it? You ought to take to dealer and let them drive it, then take all the weights of and drive it again. If it's the exhaust in some of these trucks causing problems it should be easy for GM to come up with a solution. I don't think everyone is having the same type of noise/vibration.

I drove several of them both 2014 Sierra and Silverado and every one of them had a bit of it however some definitely had it more than others. I am baffled that GM couldn't come up with or didn't care enough to implement a solution during development, surely they knew about it, especially when you look at all the stuff they put on the exhaust to eliminate drone and resonance. 2 resonators, a flex coupling, and a flapper valve for V4 drone.

14SLTZ71 Enthusiast

14SLTZ71

Posted
Posted

I have managed to get rid of about 90% of the exhaust resonance vibration in the floorboard and accelerator pedal.

This is what I have done so far;

Installed the Range V8 which helped some by keeping the engine out of V4 mode.

I Clamped weights to the pipe after the muffler but before the resonator which made a big difference (see pics below). This was done mainly to determine which area of the exhaust was generating the resonance.

I think the bent portion of the pipe going over the rear axle in the spare tire area is causing most of the resonance. The resonator right before the exhaust outlet may have something to do with it as well, but it's definitely being generated after the muffler.

Next step will be to install a helmholtz resonator like the one in the pic below. I will make it adjustable until I determine the correct length needed to cancel out the resonance, then it will become permanent.

I DID NOT WEIGH the WEIGHTS before mounting.

Ok so now I clamped the flapper valve open and it helped a little more, almost completely gone, but I may have lost a slight bit of low end torque?.. So I will probably take it off.
  • 2 weeks later...
14SLTZ71 Enthusiast

14SLTZ71

Posted
Posted

I cut the rear resonator off and tried the 32 dump mod. I removed my V8 Range Device and drove the truck. Removing the resonator helped with the vibration/buzzing sensation in the floor and gas pedal, especially after the engine warms up. Its still there but the frequency rate has slowed down so its not as aggravating.

I do hear a slight exhale and inhale if I'm standing next to the tailpipe area when I start it up or shut it down. I think the adaptive valve causes this and the resonator was put there so you wouldn't hear it.

The adaptive valve (aka; flapper valve) is not clamped open.

 

If I clamp the valve open I get a random V4 Drone and a helicopter sound.

post-127588-0-34062900-1398619811_thumb.jpg

post-127588-0-48642200-1398789295_thumb.jpg

post-127588-0-34062900-1398619811_thumb.jpg

post-127588-0-48642200-1398789295_thumb.jpg

post-127588-0-34062900-1398619811_thumb.jpg

post-127588-0-48642200-1398789295_thumb.jpg

post-127588-0-34062900-1398619811_thumb.jpg

post-127588-0-48642200-1398789295_thumb.jpg

  • 1 month later...
BR-TEXAS Enthusiast

BR-TEXAS

Posted
Posted

I cut the rear resonator off and tried the 32 dump mod. I removed my V8 Range Device and drove the truck. Removing the resonator helped with the vibration/buzzing sensation in the floor and gas pedal, especially after the engine warms up. Its still there but the frequency rate has slowed down so its not as aggravating.

I do hear a slight exhale and inhale if I'm standing next to the tailpipe area when I start it up or shut it down. I think the adaptive valve causes this and the resonator was put there so you wouldn't hear it.

The adaptive valve (aka; flapper valve) is not clamped open.

 

If I clamp the valve open I get a random V4 Drone and a helicopter sound.

Any updates?

14SLTZ71 Enthusiast

14SLTZ71

Posted
Posted

I installed the Borla CatBack Exhaust # 140544 and it had drone in V4 mode, sounded like a flutter or helicopter. So I sent it back to Borla and now I am back to the 32 dump mod. I should have installed the Borla GM version because it comes with the valve in the front pipe but it also cost $300 more.

I still have some vibration/buzzing sensation in the floorboard and accelerated pedal but now I am just trying to ignore it, which is difficult to do.

 

I'm not using my range V8 device because I need to send it back to the manufacture so they can update it, but. I have version 4 and the current version is 6+.

20L8TSierra24 Senior Enthusiast

20L8TSierra24

Posted
Posted

I installed the Borla CatBack Exhaust # 140544 and it had drone in V4 mode, sounded like a flutter or helicopter. So I sent it back to Borla and now I am back to the 32 dump mod. I should have installed the Borla GM version because it comes with the valve in the front pipe but it also cost $300 more.

I still have some vibration/buzzing sensation in the floorboard and accelerated pedal but now I am just trying to ignore it, which is difficult to do.

 

I'm not using my range V8 device because I need to send it back to the manufacture so they can update it, but. I have version 4 and the current version is 6+.

Just run it in M5 around town and you won't have the drone until your Range device comes back.
14SLTZ71 Enthusiast

14SLTZ71

Posted
Posted

Just run it in M5 around town and you won't have the drone until your Range device comes back.

Yea, I am aware of M5.

 

I've had no luck getting resolution to my floorboard vibration either.

I am pretty sure the buzzing/vibration sensation in my floorboard is from the exhaust that sits directly under my feet. GM didn't even install an exhaust shield on the underside of the drivers floorboard on these trucks. If I lift up my carpet the floor is hot under my feet, so I am pretty sure the resonance in the exhaust is vibrating the floorboard.

14SLTZ71 Enthusiast

14SLTZ71

Posted
Posted

That's what it feels like.

 

 

Do you feel it more when the truck is in 6th gear and even worse in 6th gear & V4 mode.

 

Lately I just drive around in M5 w/traction control off, sometimes I reach 70mph and the rpms are still only 2000 - 2100, but I try to stay below 65, otherwise I will put it in M6. The truck feels so much better versus driving around in D.

Spurshot Senior Enthusiast

Spurshot

Posted
Posted

I recall my brother having a flex plate balancing weight come off and he had a vibration that took a while to locate the cause of.

  • 2 weeks later...
Newm Enthusiast

Newm

Posted
Posted

Well add me to the list. I have what I would describe as a humming or vibration in my gas pedal. Not speed related but rpm and engine load related to me. It's just started and feel it between 1500 and 1850 rpms with V4 or V8 mode making no difference. More pronounced under slight load. My first thought, like some on here, is that it's exhaust related somehow. Anyone find a resolution?

14SLTZ71 Enthusiast

14SLTZ71

Posted
Posted

Well add me to the list. I have what I would describe as a humming or vibration in my gas pedal. Not speed related but rpm and engine load related to me. It's just started and feel it between 1500 and 1850 rpms with V4 or V8 mode making no difference. More pronounced under slight load. My first thought, like some on here, is that it's exhaust related somehow. Anyone find a resolution?

Dealership tells me it's the torque converter and operating within the normal characteristic of the design of the vehicle. I believe it's exhaust resonance causing the floorboard to vibrate between 1600 and 1800 rpm because the floorboard seems to be very vulnerable to vibration. I can even feel it vibrate when I make adjustments to the adjustable pedals. Probably due to the floor pan not being thick enough. I tried numerous things with very little success. A secondary or thicker floor pan would probably do the trick? For some unknown reason GM didn't even install exhaust shields on the driver's and front passenger floorboards.

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Latest Articles

  • Posts

    • newdude
      Gasser Subforum Has Been Quiet - - So, Regenerative Braking and Using L10

      By newdude · Posted

      No such thing as regenerative braking on a pure ICE vehicle.     Regenerative braking is the re-capture of energy from electric motors and stores it in the battery pack.  So hybrids, PHEV and EVs have regenerative braking.     What you are seeing is the charging system changing modes is all.  Its likely entering charge mode for some sort of reason is all.  All of the charging modes will be listed below.   As for L10 vs D.  L10 turns off automatic grade braking.  L10 puts you in control of grade downshifts where in D it will automatically do it based on brake pedal position and other factors.  Otherwise L10 and D drive exactly the same aside from that one aspect.    Battery Sulfation Mode The BCM will enter this mode when the interpreted Generator output voltage is less than 13.2 V for 45 minutes. When this condition exists the BCM will enter Charge Mode for 2–3 minutes. The BCM will then determine which mode to enter depending on voltage requirements.   Charge Mode The BCM will enter Charge Mode when ever one of the following conditions are met:   Windshield wipers are ON for more than 3 s. Climate Control Voltage Boost Mode Request is true, as sensed by the HVAC control module via serial data. High speed cooling fan, rear defogger, and HVAC high speed blower operation can cause the BCM to enter the Charge Mode. The estimated battery temperature is less than 0°C (32°F). Battery State of Charge is less than 80%. Vehicle speed is greater than 145 km/h (90 mph) A current sensor malfunction exists. System voltage is determined to be below 12.56 V When any one of these conditions is met, the system will set targeted generator output voltage to a charging voltage between 13.9–15.5 V, depending on the battery state of charge and estimated battery temperature.   Fuel Economy Mode The BCM will enter Fuel Economy Mode when the estimated battery temperature is at least 0°C (32°F) but less than or equal to 80°C (176°F), the calculated battery current is less than 15 A and greater than −8 A, and the battery state-of-charge is greater than or equal to 80%. Its targeted generator output voltage is the open circuit voltage of the battery and can be between 12.5–13.1 V. When fuel economy mode is active, the generator is not charging, only maintaining open circuit battery voltage. The BCM will exit this mode and enter Charge Mode when any of the conditions described above are present.   Headlamp Mode The BCM will enter Headlamp Mode when ever the head lamps are ON (high or low beams). Voltage will be regulated between 13.9–14.5 V.   Start Up Mode When the engine is started the BCM sets a targeted generator output voltage of 14.5 V for 30 s.   Tow/Haul Mode (if applicable) Pressing the Tow/Haul Mode button located on the center stack, the vehicle system voltage is raised and the remote (non-vehicle) battery will be charged. Having the headlamps on will raise the system voltage and if the Tow/Haul button is applied it will not serve any purpose. The voltage is regulated between 13.9-14.5 V.      
    • jaszr2
      Active Grille Delete

      By jaszr2 · Posted

      Hello from Australia Just sharing that there is now a way to delete the active shutters entirely with just a plug in module. Opens up tons of room to light bars etc.
    • jake111
      Gasser Subforum Has Been Quiet - - So, Regenerative Braking and Using L10

      By jake111 · Posted

      I have an observation and a question... 1) I watch the voltage closely because I have had to dial in the cut-in/cut-out voltages of the battery separator to my camper.  The "smart" charging drives me nuts.  Anyway, I noticed that when coasting for a while, and especially if lightly using the brakes (though not necessary), the voltage goes up from mid/high-13 volts to mid/high-14 volts.  Then it drops back down after stopping or going again.  Consistently!   The only explanation I can come up with is REGENERATIVE BRAKING!  Well, maybe that's a little bit of an exaggeration, but it's certainly free extra battery charging.   2) Driving on mountain roads I will use L and vary the max gear.  Things straighten out and I end up in L10.  Sometimes I leave it there for a while.  Is there any difference between L10 and D?   
    • devonthegreat
      anyone interested in a 2002 Chevy Silverado 4x4 parts truck NYC

      By devonthegreat · Posted

      **SOLD** Please end or delete post. thank you
    • PBNB
      Tire pressure for 37s

      By PBNB · Posted

      Do you think this width might affect the chalk test with a higher pressure closer to 65psi? I think lowering the pressure makes sense to get the tread to lay flatter

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...