Vibrations - New Vehicle

[kb9koy]

Hello All, new to the group.. Been looking thru the site and looking at a lot of the feedbacks on the vibrations issues.. This is my third Envoy (02SLE, 04SLT) and I decided to go big and get the 2008 Envoy Denali..

My other two didnt have the vibration issues at all.. My 02 had 45,000 on it with original tires, my 04 had 65,000 and just bought new tires before I traded it in..

I guess here's my issue, I have a slight vibration that seems to be mostly at the higher speeds.. The dealer basically thinks Im nuts.. They went and rebalanced the wheels(Goodyear Fortera's), and re-torqued the suspension and motor mounts.. Im supposed to stop back later today and let them know if it helped.. (It did not..) Not sure what to really tell them.. Ive explained this the best I can but they give you the "We'll take a look at it" and 2hrs later come back and tell you nothing is wrong..

Any and all suggestions would be apprieciated??

[dtown]

Can you have one of the ride with you to point out the occurance?

[kb9koy]

Can you have one of the ride with you to point out the occurance?

The tech did drive it and said nothing was wrong.. The service writer got me and the tech and I drove it in there back lot which has a side street.. You can get it up to 45-50mph.. Got up to that speed and he said he noticed alittle vibration.. He then took it back in said he retorqued the motor mounts and suspension, and rebalanced the wheels.. Said 3 of 4 wheels were 1/4ounce off.. The service writer told me that it probably wasnt that but to take the vehicle home and see if it helped..

[ylab]

Sometimes there can be an imbalance, even though the tires show as balanced on the machine. This can happen when the low or high spots of both the rim and tire are close to each other. In order to fix it, they need to un-bead the tire and rotate it 90 degrees on the rim and then rebalance. The problem will usually go away, unless there's a problem with one of the tires. (We are talking Goodyear here and its possible there's a bad ply or cord causing the vibration). They can also try swapping the tires from front to back or side to side (if not a directional tread) and see if the vibration changes or goes away.....on occasion, a tire may cause a problem turning one way, but not the opposite.

Other causes could be a bad or missing spring insulator and even stones wedged in the tire. I would have a vibration half way home from my wife's house when we were still dating and was sure there was a balance problem, but couldn't understand why it tended to go away about 5-10 minutes after getting on the highway. She had a stone driveway and the tires would pickup a stone or two and cause a vibration until the stone would finally get thrown off at highway speeds.

[PROSPHOTO]

I hope they're giving you a loaner car every time you bring it in :undecided

Anyway...GM trains [some] of their Techs on proper vibration diagnosis and correction. They [should] have the proper, required diagnostic tools to properly diagnose what order vibration it is (1st, 2nd) and then to pinpoint the location of the vibration. You could always ask the service manager if any of their techs have been trained in vibration correction :yes:

There are so many more possibilities beyond engine mounts and tires that can be causing your concern; but only a trained, capable tech is going to be able to isolate it :yes: Wost case scenerio, the dealer will have to get a field engineer involved to isolate the vibration :undecided

Good luck & keep us posted :D

[petevw]

When the tech did the re-balancing, did they check to make sure that the tire(s) were not out of round? There's a maximum allowed run-out for each tire (Goodyear and/or GM specs).

A bad shock can do the same too, although you wouldn't think it would happen w/ a new vehicle.....it's possible though.

[Envoy Fan]

Have the tires and wheels been road forced balanced with a GSP 9700 Hunter machine? This will let the tech (if he knows how to operate the machine) know if a bad tire or wheel. Sometimes the problem can be solved as Ylab mentioned by rotating the tire on the rim.

[kb9koy]

I have about 3500 miles on it now.. I did the first oil change and tire rotation about 2000.. It had the vibration before I had the tires rotated, and since the rotation, it seems to be the same.. Thats why I was kind of ruling the tires out and saying its something else.. It going in later tonight and we'll see what they say.. Im feeling the vibration in everything and not just the steering wheel.. My wife notices it in the floorboards.. I had her grab ahold of the steering wheel at speed and she could feel it as well..

I guess the best way to explain is holding a Dremel went its on low..

[petevw]

Sometimes the problem can be solved as Ylab mentioned by rotating the tire on the rim.

That only makes the area where you put the weights change. To minimize weights, there is usually a yellow or white dot on the sidewall that is supposed to be lined up w/ the valve stem to counter some of that, but rotating the tire on the rim will only move weights around.

If the tires have been balanced by a competent tech, then i still would be looking for bad tire (out of round, bad cord, etc)

[kb9koy]

Have the tires and wheels been road forced balanced with a GSP 9700 Hunter machine? This will let the tech (if he knows how to operate the machine) know if a bad tire or wheel. Sometimes the problem can be solved as Ylab mentioned by rotating the tire on the rim.

They have a Snap-On tire balancer.. Not sure how old the machine is.. The dealership use to do tires along time ago and got out of it.. They were sending everyone with a tire issue to the Goodyear dealer up the road.. Now, a few years later, the dealership is doing everything in house.. (I guess Goodyear wasnt giving them a good rate on the services..)

[PROSPHOTO]

That only makes the area where you put the weights change. To minimize weights, there is usually a yellow or white dot on the sidewall that is supposed to be lined up w/ the valve stem to counter some of that, but rotating the tire on the rim will only move weights around.

Not exactly true...the 9700 will measure the run-out and balance on both the tire and the wheel...then have you rotate the tire on the wheel based on the measurements that it took...I've seen wheels go from 1.5oz to 0.25oz using this machine :yes:

[petevw]

I'm not familiar w/ that machine...sounds pretty high end. I've used the more common, lower end units, and that's what I was explaining (in case they don't have that machine).

Sounds like a neat machine...love to see one in action.

[ylab]

Shot in the dark, but this was a known problem for noise and/or slight vibrations in prior years, have they checked the oil cooler lines and dipstick/fill tube on the tranny? There's been instances where they tap against the exhaust heat shield or tunnel causing a slight vibration.

The other thought would be to loosen and then re-tighten the exhaust bolts around the converter with everything cold. I've seen instances on other vehicles where this could setup a harmonic vibration if the system wasn't aligned quite right. (When I first installed my exhaust, my wife insisted she could feel the rumble or exhaust when I accelerated.....loosened and re-tightened before driving it one morning and the vibration was gone).

[kb9koy]

I guess depending on what the dealer says later tonight, would it be advisable just to take it to the GoodYear dealer up the street from the dealership?? I would say its a safe assumption they could Force Balance the tires..

[Envoy Fan]

I guess depending on what the dealer says later tonight, would it be advisable just to take it to the GoodYear dealer up the street from the dealership?? I would say its a safe assumption they could Force Balance the tires..

Most dealers have been urged by GM to get into the tire business. Ask your dealer if they have a Hunter GSP 9700 machine. (Google Hunter GSP 9700 and see what all this machine can do) If they say no, find a tire store or perhaps the Chevrolet dealer has one. As the wheels on the GMC and Chevrolet cars and trucks have gotten larger (20"+) and heavier, it is almost a necessity for each dealer to have one.

[kb9koy]

Most dealers have been urged by GM to get into the tire business. Ask your dealer if they have a Hunter GSP 9700 machine. (Google Hunter GSP 9700 and see what all this machine can do) If they say no, find a tire store or perhaps the Chevrolet dealer has one. As the wheels on the GMC and Chevrolet cars and trucks have gotten larger (20"+) and heavier, it is almost a necessity for each dealer to have one.

Did a quick search and the Chevy dealer up the street does have one.. When I take it in tonight Ill let my dealer know.. Maybe they/I can take it there and have them do it..

[LPlum]

I have 2006 trailblazer that I recently purchased with 24K miles. It has a vibration that starts at 55-58 mph. I rotated the tires, which had no affect. The one thing that seems to change this vibration is to down shift, so I think it is drivetrain related. I need to have the dealer take a look, but I know it will be a run around.
Thanks, Lowell

[n0kfb]

Are you sure this is a tire problem? Maybe you have an issue with the DoD/Active Fuel Management system.

-- Dan Meyer :coffee

[ranger482]

I am having the exact same vibration, but mine is definately coming from the rear end. I have done u-joints twice now, rotated the tires, and even pulled the rear pumpkin cover off to look at the gears. I cannot find it... mine only vibrates when i step on the gas. It starts at around 35 and is noticeable most around 40 ... tonight i took off the left rear rotor and cleaned everything up, and i think it made some difference. My e-brake shoes were cracking around the edges, so i chipped off the loose parts and sanded the edges, and broke the rust rings off my rotor. I think it is a bit smoother, but i will find out in the next couple days. If it is, i am prolly gonna pull the other side apart and do the same. Otherwise, i am thinking it has to be outer axle bearings, which i have heard are not easy? Oh well, i am about ready to get rid of this thing....

[Exit32]

I have about 3500 miles on it now.. I did the first oil change and tire rotation about 2000.. It had the vibration before I had the tires rotated, and since the rotation, it seems to be the same.. Thats why I was kind of ruling the tires out and saying its something else.. It going in later tonight and we'll see what they say.. Im feeling the vibration in everything and not just the steering wheel.. My wife notices it in the floorboards.. I had her grab ahold of the steering wheel at speed and she could feel it as well..

I guess the best way to explain is holding a Dremel went its on low..

Dremel, eh? Betcha it's the driveshaft. Ask your dealer to examine the rear driveshaft to see if was damaged during transit. Could be dented; could be bent; could have a missing balance weight; or it could be a defective or improperly installed u-joint. It's also possible that the driveshaft was just never balanced properly at the factory.

If your driveshaft passes visual inspection, ask the technician to disconnect the rear u-joint, rotate the driveshaft 180 degrees, and reinstall it. Then test drive the vehicle to see if the vibration has changed. If so, you need a new driveshaft.

[kb9koy]

I gave the dealer my vehicle for two full days and they cant seem to find it.. A different tech and the service manager took it for a ride and they told me that they can feel a SLIGHT vibration.. Supposedly they used a vibration sensor and moved it all around the vehicle, but they cant find out where its coming from.. The gave my Envoy back and said to basically drive it and see if it gets worse.. If it does, they will probably be able to find it easier then.. So hopefully tonight, the truck goes into Discount Tire.. Supposedly they have the Hunter GSP balancer.. At least then the tires will be ruled out..

On a side note, does anyone have the Goodyear Fortera's on their Trail/Envoys?? Ive looking thru a few other tire sites and alot of people are complaining about vibrations and bad tire wear with them..

[PROSPHOTO]

On a side note, does anyone have the Goodyear Fortera's on their Trail/Envoys?? Ive looking thru a few other tire sites and alot of people are complaining about vibrations and bad tire wear with them..

I have the Conti's and love them...my Brother-in-Law had the Fortera's and needed to replace them after 18K; they were bald :suicide:

I will get the J # for the correct vibration tool to use in diagnosing vibrations...the dealers are required to have the tool, but I doubt it if they have anyone trained to use it :bonk:

EDIT: J 38792-A Electronic Vibration Analyzer ...The tool wil display the frequency of the vibration and then the tech can go further in their diagnosis

Vibration diagnosis involves the following simple outline:

Measure the repetitive motion and assign a value to the measurement in cycles per second or cycles per minute.
Relate the frequency back on terms of the rotational speed of a component that is operating at the same rate or speed.
Inspect and test the components for conditions that cause vibration.


The problem is that a Tech working on flat rate is not going to get paid for all of the diagnostic time required, and therefore does not take the time to properly diagnose the problem.

My suggestion is to call the 800 customer service # in your owners manual. Once GM is involved they will follow the dealers diagnosis and/or send out an engineer to diagnose the concern...that's how you get the job done when all else fails :yes:

[07Trail]

I understand your issues with vibration. My 07 was vibrating at high speeds when applying brake since new. I went round and round with the dealership and the i had to call GMAC. After 2 months of running back and forth and a lot of bull--/* they finally tried looking at the brake system. I guess from what i am told is that there was only 3 cases including mine that the master cylinder was bad. After all of that including tires replaced, road forced, motor mounts, drive train, 3 sets of rotors and hours in the shop that was the issue.

[Miles1106]

My Olds Bravada is vibrating at speeds between 70 and 75 mph. Its smooth as a baby bottom before that and a little bumpy but very drivable after that. I took it to the dealer and after some bull@#$% and two techs, I found out that my driveshaft was out of balance. The old tech told me that he couldn't check the vehicle right because I had a little cup in my tire on the rear. I had to pay and me and my wife Bit#$@^ hard. So they assigned us to another tech who sent the driveshaft to get balanced and it drove a little better.

During the stupid conversation with the first tech I was told that he let the rear suspension hang with the vehicle lifted and there was no vibration. DUH, the load was taken off of the suspension. Well anyhow that gave me an idea. I went and put some Monroes on the rear and the vibration got a little better.

After the driveshaft balance and the new rear shocks on the air springs the SUV is at least drivable at the highway cruise speed. It used to sound like I was riding on the damn rumble strips at highway cruise speed. I still feel the vibration but I think I may need tires or bearings somewhere. I have to drive it until it breaks. I have those faulty Firestone Fuzion tires on it now. I work with a prior GM drivetrain tech and he said that Goodyear and Firestone tires for these vehicles suck. Get Bridgestones or better yet Michellins.