Jump to content

Recommended Posts

Well boys and girls.. I got my new michelin tires put on yesterday and drove it at my normal speeds today and i have to say it feels like the vibration is all about gone.. Dont wanna say for sure yet but i only got a minoot vibration in the counsel and wheel. And the car seems to ride better with these tires. Ill give it a week before i say they fixed 99% of the vibration but the ride into work and home was the best ride ive had at highway speeds yet..

  • Like 1
Link to comment
Share on other sites

OK, GM gurus.

 

I did the dirty and bought new tires. BF Goodrich. It took away a lot of vibes from the truck but still there.

 

On my highway commute today, I noticed something that had been masked by the vibration from the goodyears. Set cruise at 75. The vibration is more noticeable when going uphill and downhill. The thing that was different was when it kicked down to a lower gear on the uphill, the vibration frequency sped up (increased).

 

Ideas? I am no expert and would like the dealer to check it out but want to give them some hints at what we think would make that happen. Any simple tests I can do that would confirm your idea?

 

I have been learning about driveline working angles and hearing some issues with those on stock ride heights. Could that be it?

Shameless Bump for answers????
Link to comment
Share on other sites

Unfortunately I think I'm part of the club experiencing the vibration problem. Picked up my new LTZ last Thursday evening and noticed vibration issues at 35 and 65+ the next day. Thought it might be due to flat spots on my tires as the vehicle had been in their inventory for 9 months and hadn't even been test driven (4mi on odometer). Decided to drive it around over the weekend but problem persists and may be slightly more noticeable. Took truck to dealer for another issue Monday morning and relayed my concern to salesman. He indicated they ask customers to drive 500 miles to give tires with flat spots a chance to resolve the flat spots. Im already at 400, but not confident it's going to miraculously clear up in 100 more miles...Sent him an email expressing concern to see if I can get them to move ahead with diagnosing/resolving while it's already in shop. Waiting to hear back.

Does the dealer have any sort of 30 day return policy? I would give the truck back or else you will be in the same boat as the rest of us.

 

I have been fighting with GM for 3 months now. They came back last week and said it was working "as normal" and there was nothing else they could do. They will lower their standards so that they can say its "normal" but we all know its far from normal. I filed a BBB complaint even without the 3 attempts because the dealer refused to look at it a 3rd time. Once I filed the complaint it got their attention as I received a call from GM yesterday and they reopened the case. Who knows if it will get me anywhere but if nothing it resolved by the end of the year I am trading it in.

 

I just cant beleive they cannot figure out the issue....or they don't even care and no one is really working on it.

Link to comment
Share on other sites

OK, GM gurus.

 

I did the dirty and bought new tires. BF Goodrich. It took away a lot of vibes from the truck but still there.

 

On my highway commute today, I noticed something that had been masked by the vibration from the goodyears. Set cruise at 75. The vibration is more noticeable when going uphill and downhill. The thing that was different was when it kicked down to a lower gear on the uphill, the vibration frequency sped up (increased).

 

Ideas? I am no expert and would like the dealer to check it out but want to give them some hints at what we think would make that happen. Any simple tests I can do that would confirm your idea?

 

I have been learning about driveline working angles and hearing some issues with those on stock ride heights. Could that be it?

I feel that it is an engine/exhaust frequency that makes the fire wall have a vibration which then carries through anything attatched. Mine has the vib in the gas peddle only when driving around town and it goes with the engine RPM, it seems to do it more often when the torque converter is looked up which is 3rd gear and up and lugging the engine at a steady speed. Mine also has an oil pump whine which I have had replaced with no change in noise and I can feel the vib go with the sound of the oil pump noise. I then found out by a cut a way pump they have a vane style pump.The oil pumps in the new ecotec3/LT1 engines have an extra vane style rotor on the front of the pump compared to the old engine pumps. Vane pumps naturally make a hi frequency noise, for example like an air die grinder. I think the pump can be transmitting with the engine and exhaust to cause the hi frequency vib in the fire wall we are feeling. I also can feel the same vib in the peddle if im next to a loud truck or Harley at a stop light or sitting a RR crossing when the train engine come by. This is just my observation on it

  • Like 1
Link to comment
Share on other sites

according to http://oemdtc.com/6392/information-on-vibration-analysis-and-diagnostic-2014-2015-chevrolet-silverado-gmc-sierra there is an issue with the Cat i believe it was, where the cross member causes excessive resonance a la vibration.... I don't remember if it was on any specific engine. I know I have it on my 4.3 V6... I've been doing a lot of highway driving the last few days have found that specifically at 42-46 MPH the vibration is at its worst, but still always there. next worse is either 53-55 or 63-65.... not sure why its these speeds in particular are the worst, but it is definitely getting worse on top of it. My truck did the thing where the vibration actually shakes the truck right and left again, this is only the third time its done this... no clue what sets it off.

Link to comment
Share on other sites

OK, GM gurus.I did the dirty and bought new tires. BF Goodrich. It took away a lot of vibes from the truck but still there.On my highway commute today, I noticed something that had been masked by the vibration from the goodyears. Set cruise at 75. The vibration is more noticeable when going uphill and downhill. The thing that was different was when it kicked down to a lower gear on the uphill, the vibration frequency sped up (increased).Ideas? I am no expert and would like the dealer to check it out but want to give them some hints at what we think would make that happen. Any simple tests I can do that would confirm your idea?I have been learning about driveline working angles and hearing some issues with those on stock ride heights. Could that be it?

Based on your observations, the working angles of the u-joints would have nothing to do with the observed vibration. When the transmission shifts to a lower gear, and the engine sped up, you said the frequency of e vibration your were feeling went higher. This suggests that the vibration is a function of engine rpm, not driveline speed (at least, from the output of the transmission all the way to the tires). Unless the vehicle speed magically jumped up a whole lot at the same instant in time as the engine rpm's (which makes no sense, of course), your vehicle is exhibiting a vibration that is a function of engine speed, not driveline speed. Of course, the dealer could confirm this with the all-to-famous "Pico" meter!

 

I gotta wonder if this isn't something in the engine balance, or the torque converter, or the input section of the transmission. Maybe the pump in the transmission. Maybe not. Seems that most people don't report a vibration with the vehicle in neutral and revving up the engine. So that would rule out the engine mechanical, the flex plate, the torque converter (unlocked!), and the input shaft of the transmission.

 

However, an engine can behave extremely differently unloaded and loaded. Including the exhaust. Don't recall what the info posted regarding the muffler or the Cat or whatever it was, but very interesting.

Link to comment
Share on other sites

Based on your observations, the working angles of the u-joints would have nothing to do with the observed vibration. When the transmission shifts to a lower gear, and the engine sped up, you said the frequency of e vibration your were feeling went higher. This suggests that the vibration is a function of engine rpm, not driveline speed (at least, from the output of the transmission all the way to the tires). Unless the vehicle speed magically jumped up a whole lot at the same instant in time as the engine rpm's (which makes no sense, of course), your vehicle is exhibiting a vibration that is a function of engine speed, not driveline speed. Of course, the dealer could confirm this with the all-to-famous "Pico" meter!

 

I gotta wonder if this isn't something in the engine balance, or the torque converter, or the input section of the transmission. Maybe the pump in the transmission. Maybe not. Seems that most people don't report a vibration with the vehicle in neutral and revving up the engine. So that would rule out the engine mechanical, the flex plate, the torque converter (unlocked!), and the input shaft of the transmission.

 

However, an engine can behave extremely differently unloaded and loaded. Including the exhaust. Don't recall what the info posted regarding the muffler or the Cat or whatever it was, but very interesting.

sorry I didn't remembered it correctly. and it is V6 Only

 

"Condition 5:

Vibration Felt in 4 Cyl Mode (AFM) – V6 Engine OnlySeveral customers have commented on a vibration felt in the steering wheel or seat during 4 Cylinder Active Fuel Management (AFM) operation. This can be noticed more at 64-72 km/h (40-45 mph) and by lightly accelerating to the point where the enginetransitions to 6 cylinders, or V6 mode.

This type of vibration can be the result of exhaust cross pipe ground out and/or cab mount ground out.

To repair this condition, the three-way catalytic converter settling procedure in PIP5228: Vibration During Active Fuel Management V4 Mode Operation 1200–1400 Engine RPM should be completed."

Edited by Jesse D
Link to comment
Share on other sites

Based on your observations, the working angles of the u-joints would have nothing to do with the observed vibration. When the transmission shifts to a lower gear, and the engine sped up, you said the frequency of e vibration your were feeling went higher. This suggests that the vibration is a function of engine rpm, not driveline speed (at least, from the output of the transmission all the way to the tires). Unless the vehicle speed magically jumped up a whole lot at the same instant in time as the engine rpm's (which makes no sense, of course), your vehicle is exhibiting a vibration that is a function of engine speed, not driveline speed. Of course, the dealer could confirm this with the all-to-famous "Pico" meter!

 

I gotta wonder if this isn't something in the engine balance, or the torque converter, or the input section of the transmission. Maybe the pump in the transmission. Maybe not. Seems that most people don't report a vibration with the vehicle in neutral and revving up the engine. So that would rule out the engine mechanical, the flex plate, the torque converter (unlocked!), and the input shaft of the transmission.

 

However, an engine can behave extremely differently unloaded and loaded. Including the exhaust. Don't recall what the info posted regarding the muffler or the Cat or whatever it was, but very interesting.

I agree, possibly one of the planetary sets has a bad sun, ring or planet gear, bent shaft or out of round drum.

Link to comment
Share on other sites

Does anyone know if there is a way to upload a file on here for other members to download? I have created an excel spread sheet that will tell you the rpm and frequency of the drive train based upon vehicle speed, if anyone is interested I can walk you through using a vibration app on your phone that will tell you the frequencies that the vibrations you are feeling are occurring compare them to the spread sheet and you could have an idea of the component(s) and vibration type, ie 1st order, 2nd order, 3rd order. The two combined are the poor mans PICO scope. You need a smart phone, I use android but I'm sure Iphones have similar apps that will do the same. It takes a phone with decent processor power to obtain a high enough sample rate for the data. If anyone is interested let me know, I'd really like to see how other people's data compares to mine.

Link to comment
Share on other sites

This is the only thing bugging me right now. If all goes well my current daily that is driving me insane with issues (not a gm truck not that it matters) is going to be traded on a 2015 double cab 4x4 6.2 truck. I test drove a 2015 crew 6.5' 6.2 NHT and at anything over 60 mph the truck started to vibrate. If I get one the p rated tires they have aren't even leaving the lot as they won't last on pit run so hopefully it doesn't vibrate. Seems luck if the draw though....

 

Sent from my SM-G900W8 using Tapatalk

Link to comment
Share on other sites

I did a little more testing. Set cruise at 80, and went into manual mode. Flat surface in M6 in V6 mode (AFM not on). Vibration was annoying. Dropped to M5. The vibration was still there and a little less annoying. Dropped to M4, the vibration must reach a resonance or frequency that sort of tunes itself out. It felt better.

 

My AFM vibration is absolutely horrible and I am guessing it is that way because of something wrong described in the reasons above.

 

The vibration is steering wheel and seat.

 

I deleted the muffler a while back and am running the flapper open.

 

It did not matter whether the muffler and flapper were on the truck because it still did the same vibrations.

  • Like 1
Link to comment
Share on other sites

Well, I am also a victim of the famous shake. Mine is at 70+ and also vibrates the center console and seats. I talked to my service writer at my dealership who immediately contacted the Service Manger. He is handling it personally. They have already sated that they would be more then willing to assist me with this. The Sales Manager immediately jumped on this forum to read peoples complaints, as they have no heard of this issue yet. He started with road force balancing the tires, and then hooked the entire truck up to several vibration sensors, and drove it on the highway. When he returned he stated that he immediately felt the vibration and the truck "failed" the tests. As i sit here in the dealership now, they have seven techs looking at the front end of my truck and he's using it as a "teaching" tool to the other techs. He said he thinks he has the issue addressed however has not come back to me with exact details. I will be sure to post when i have a resolution, hopefully we can get to the bottom of it.

 

I will post with any updates as it gets addressed or not. However HUGE shoutout to my dealer who has been more than accommodating with the issue, and seemingly have done everything they can to address my concerns.

  • Like 1
Link to comment
Share on other sites

Well, I am also a victim of the famous shake. Mine is at 70+ and also vibrates the center console and seats. I talked to my service writer at my dealership who immediately contacted the Service Manger. He is handling it personally. They have already sated that they would be more then willing to assist me with this. The Sales Manager immediately jumped on this forum to read peoples complaints, as they have no heard of this issue yet. He started with road force balancing the tires, and then hooked the entire truck up to several vibration sensors, and drove it on the highway. When he returned he stated that he immediately felt the vibration and the truck "failed" the tests. As i sit here in the dealership now, they have seven techs looking at the front end of my truck and he's using it as a "teaching" tool to the other techs. He said he thinks he has the issue addressed however has not come back to me with exact details. I will be sure to post when i have a resolution, hopefully we can get to the bottom of it.

 

I will post with any updates as it gets addressed or not. However HUGE shoutout to my dealer who has been more than accommodating with the issue, and seemingly have done everything they can to address my concerns.

 

Well, I am also a victim of the famous shake. Mine is at 70+ and also vibrates the center console and seats. I talked to my service writer at my dealership who immediately contacted the Service Manger. He is handling it personally. They have already sated that they would be more then willing to assist me with this. The Sales Manager immediately jumped on this forum to read peoples complaints, as they have no heard of this issue yet. He started with road force balancing the tires, and then hooked the entire truck up to several vibration sensors, and drove it on the highway. When he returned he stated that he immediately felt the vibration and the truck "failed" the tests. As i sit here in the dealership now, they have seven techs looking at the front end of my truck and he's using it as a "teaching" tool to the other techs. He said he thinks he has the issue addressed however has not come back to me with exact details. I will be sure to post when i have a resolution, hopefully we can get to the bottom of it.

 

I will post with any updates as it gets addressed or not. However HUGE shoutout to my dealer who has been more than accommodating with the issue, and seemingly have done everything they can to address my concerns.

where is your dealer? sounds like we all should go there hahaha

  • Like 2
Link to comment
Share on other sites

Well guys can't say my experience has been near as pleasant as everyone else's. So my truck has been at the dealership since last Friday, which collectively is near 40 days in total. They are saying my truck does not vibrate and the pico tests say the truck is well below spec. Unfortunately the truck still vibrates! If the truck no longer vibrated they would have released the truck to me already. They took off my 20" wheels and replaced them with 18" wheels and tires. The vibrations were less with the bigger sidewall tire but the truck picked up a dull resonating noise in the cab.

 

With all that being said they are having a GM Field Service Engineer come out and look at the truck. Still find it odd that the truck is supposedly vibration free but they are having the FSE to come look at it. Oh forgot to mention, the Operations Manager accused me of mentally imagining the vibration. Beware all, they know of the issue but are doing their best to push you out the door.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.




×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.