2004 LeSabre Vibration Problem

[Stevansky]

I bought a used 2004 LeSabre with less than 20k on it. They made me a good deal on it, factory warranty left, etc. Not long after I got home with it I noticed that over 60mph I got a vibration that got worse the faster I went. Thinking the tires were out of balance I had them balance, no help. Went back to the dealer, he advised I had a tire out of round, replaced it, no help. Took it back to the dealer test drove it with a mech. and they checked all the tires, "no problem found". The head mechanic recommended I replace the factory tires with Michelin HydoEdge. Bought the tires NO HELP!

I'm going back to the dealer tomorrow and they're going to roadtest it again. Anyone else have this problem in a LeSabre?? I can only think of four other things that might cause this: rotors, struts, velocity joints, or the transmission.

[yogi_123rd]

You left out "front wheel bearing" from your list.

[Stevansky]

Oops! Figured the wheel bearing was included in the CVJ assembly. They drove it again today, the "Blue Team" service mngr. explained again that everything was in spec. and that if a "serious" problem occurred I still had warranty. I "explained" to the dealership managers that to me this is a serious problem. Then talked to the main shop manager who agreed to keep the car a few days and do an "EVA" test to determine where the vibration is coming from and if it is fixable. He said that if the measured vibrations were below a certain level that it would be considered in tolerance. Gave me another car to drive and I came home. IT DOES THE SAME THING! I think Buick (and GM in general) need to invest more in R&D in solving these problems instead of expecting everyone to just accept them as normal.

[Lasota]

This is what happens when the big three push their suppliers for cheaper parts, something has to give. I work for a OEM parts supplier and they are constantly wanting cost reductions from us. The end result is what you are experiencing, lousy cars. I own a 94 and a 00 LeSabre, I have had more problems with the 00 than the 94. I just got the recall notice for the coolant leak issue in the manifold, the great GM fix is for the dealer to change the fastners and add stop leak to the rad. I have had enough, I always owned NA vehicles up until now, I bought myself a Volvo and I don't think I will be back.

[timrice]

How about play in a tie rod? Wouldn't think that could be it with such a new car, but I recently had bad vibration on my '91 Park Ave., and found I had tie rod issues. Got that taken care of, and no more problem.

[fischmama]

I have the same problem with my 97 Park Avenue. Even at lower speeds it started to vibrate, i could see the steering wheel moving at 15mph.
I took it to a local shop that also did a bunch of other stuff on it (engine swap at 125000miles) and they found that the front left tire was damaged (deformed). Well of course they replaced it, but i didn't fix the issue completly.

After the new tire and proper balancing it still shakes at higher speeds (like 50+).
I know that my front left wheel bearing makes noises when i turn right, but i don't think it causes the vibration if it would i'm certain would feel it in the steering wheel.

fischmama

[pcmos]

I am an engineering major at ASU right now. Personally I own a 2000 LeSabre with the same problem. Based on what I have observed in GM's reaction to this complaint, I believe the source of the vibration propogation is the design of the control arm itself. I say the source of propogation because any rotating mass assembly will have some minor balance issue, GM claims the control arm is "sensative to an out of balance" rotating mass assembly. Essentially the control arm is allowing this vibration to be transfered from the hub assembly to the engine frame and up through the body and rack and pinion. The question is whether I can do something to stop this transfer from occuring. GM's response was to simply change the bushing design on the control arm, where it mounts to the engine frame. They did this only for the Park Avenue and Bonneville models I believe and they claim customers who are "tuned into" the vibration may still feel it. Why? Because making the bushings softer is a very cheap fix. The vibration should never reach the bushing in the first place. Personally I believe that the control arm isn't heavy enough to counter minor vibrations with its own momentum. If the control arm were made from stamped heavy gauge steel like they used to be, instead of lighter cast aluminum, it wouldn't react to minor vibrations originating in the hub assembly. I may experiment with some simple modifications to see if I get any better results. In the mean time, please note that you can try a dealer who has a "road force" dynamic balancer which will put a simulated weight load on the tire during the balance procedure. This results in a much more precise balance and with a set of Michelin Symetry tires I was able to almost eliminate the problem for a long time. Those tires are now worn out on my car and the vibration is much more noticable.

[imidazol97]

Originally Posted by pcmos

I believe the source of the vibration propogation is the design of the control arm itself.

You are somewhat on the right track. The problem is the rotating mass of the tire and wheel doesn't roll round. A. The wheel and tire assembly may be out of balance-one side heavier than the other. B. The wheel and tire may not be round causing the center of the wheel/tire to move up and down as it rotates OR the tire may not crush the same amount on each part as it rolls which means the center of wheel/tire moves up and down.

The latter is what is compensated for by using a Hunter 9700 wheel balancer. My dealer bought one early on in the game. When I bought my 03 LeSabre the problem with the stiffer chassis was well understood. My Michelins were somewhat out of round but mostly within the 17 or 19 pounds considered not suitable. Mine were 6, 9, 12, 13. Most other brands new tires were much higher.

The problem is tire quality coming from manufacturers affecting the car. GM had started replacing ParkAve and Cadillac problem tires with Michelin SYmmetrys. When I bought my LeSabre, I got it because the Celebrations all had Symmetrys--I have chosen Michelins since 1967. I just replaced 98 LeSabre tires with Harmonys and they are good--tire store balanced and they don't need Hunter 9700 Road Force. Neither did the X-Ones they replaced. Different car chassis. Not the Aurora chassis evolved like 2000+ cars.

The vibration analyzer showed tire interactions. My service manager was good at persisting--I am sensitive to out of balance. I clued him that the vibration came on smooth asphalt interstate on slight uphill grades on a trip to Nashville--didn't happen on downgrade. He pulled car back in after feeling tire wear and found alignment on rears was toed in not at middle of range. They were within tolerance but not at mid setting. He changed the toe on fronts to what he considered the optimum setting. Vibration gone. Note: he was an alignment mechanic early in his career. So he knows the shop methods.

The aluminum alloy parts in the A-arm and other suspension and chassis components is to save weight for mileage purposes. The frame is stiffer for a better quality car. The light parts react more to slight forces shaking the rotating wheel. This is not a design mistake. The lack of quality tires is one factor. At 30K miles my wheels still were in good balance but tires had worn some because I kept one set on rear longer than 8000 Mi intentionally. I had them rebalanced. Good tires stay round and stay balanced better. I can't afford to buy cheap tires.

Good luck.

[pcmos]

Frankly I disagree, this is certainly a design mistake. Any self respecting engineer who designed an entire vehicle platform should certainly have taken into account normal vibrations resulting from tire anomolies and slight alignment error. Every time I drive my LeSabre on the highway I am reminded of why I have to pound 800 pages of vibration analysis into my head this semester. There is no question that any mechanic who examines the complaint will determine that it originates in the tire. Assuming the engine and transmission don't contribute much in the way of speed related vehicle vibration, all of the vibration you feel in a car originates in the tire/wheel assembly. There is also no question that cheap tires are not well balanced and that if we could assemble a tire and wheel with ideal balance, vibration would be eliminated. The tire and wheel vibrate at any speed, you only feel it when it strikes a resonance with some component between you and the hub. fortunately most parts are so irregular in shape and have so many nodes that resonance occurs in an infinately small range of frequencies, or at frequencies that would exceed the frequencies of vibrations resulting from the motion of the wheel assembly at normal road speeds. The job of an engineer is to do one of two things, either eliminate the possibility of resonance occuring with any given part under normal operation, or isolate the vibration using proper attachemts. There are only 8 significant points where wheel motion can transfer to the body in a LeSabre, 6 frame mount positions and the upper mount of both front strut assemblies. I can gauruntee you that the frame mounts are NOT stiff by performance car standards, in fact the design scheme used to attach the front frame of this vehicle to the body is one of just a few reasons why it doesn't handle like a BMW 7 series. By the way, the H body platform has been scrapped by GM, it was used in limited models throughout the late 90's and early 00's and is now dead, probably because of how poorly it was designed. The line that separates a serious luxury performance car from a boat like the LeSabre is very thin and very grey. Essentially if GM took the time that it takes to consider every aspect of the design with the same level of care and detail, you would be paying 80k for the car and it wouldn't be branded a Buick, but it also wouldn't vibrate at 70 mph. I have not had a chance to go outside and experiment with some different modifications to try and tune out the vibration. By clamping the frame along the rail that the control arm attaches to, I should be able to alter the natural resonance of the frame itself and raise it significantly. Obviously this will result in a little extra road feel but the resonance vibrations should disappear. Adding mass to the control arm is another option, but upon further examination, I am so confident that the extended stretch of un-restrained frame is responsible, I'm going to attempt to attack that first. Obviously modifications I make to the primary structural element of the front of the car require careful consideration and analysis. I have some prototype ideas in mind, concepts that will at least let me test my theory before making any permanent modifications. I just got done modifying and installing a new magnasteer rack, I altered the calibration using a tech 2 to reduce the assist overall and I re-built the inner ties using some bushings that I machined on my own. Before I can mess with the vibration I need to finish up the steering mods, the car already handles about 40x better, but thats for another post.

[polarzak]

Lots of good reading here. I had this problem with my 00. I had my Michelin tires balanced at three different shops within a week, and still the vibration was there. I gave up and decided to live with it. One morning driving to work, I noticed the vibration was gone. The car was so smooth. I have no clue why the vibration went away, seemingly by itself. For two years it was vibration free. Then I had the left front bearing replaced a month ago.Viibration is baaaaaak. Shop replaced the new bearing. Still vibrates. I am giving up and giving the car to my wife. She doesn't notice the problem.

[auto trainy]

I'll put in my 2 cents,I recently aquired a 2001 Le Sabre and had a history warranty repair done and both front tie rod ends were replaced within 11000 miles so maybey there is some truth here,have a good front end shop check it.

[rostam]

The vibration you experience is likely a sharp high frequency one usualy accuring between 70 - 80 km/hr only on stright line (on a turn around the same speed it will disapear totaly) with no sign of shaking in the stearing wheel. what kind of mechanic including your dealer diagnose this to be a tire imbalance issue. Typical north american part changers ripping you off for something totaly irrelevent.

[polarzak]

Originally Posted by rostam

The vibration you experience is likely a sharp high frequency one usualy accuring between 70 - 80 km/hr only on stright line (on a turn around the same speed it will disapear totaly) with no sign of shaking in the stearing wheel. what kind of mechanic including your dealer diagnose this to be a tire imbalance issue. Typical north american part changers ripping you off for something totaly irrelevent.

This is not what I am experiencing. Mine seem to start around 100km/hr (66mph) and there is a slight vibration in the steering wheel. I have had the tires balanced at two separate garages, no change. Although the car tracks perfectly straight, I am going in for an alignment today. Maybe something is loose.

[HotZ28]

I will have to respectively disagree with the assumption that this type of vibration is a design flaw, if it was, they would all vibrate when purchased new. I do agree, that slight imperfections in brake replacement parts and wear to suspension components can contribute to a vibration. When you buy a used car, you have no idea what parts have been replaced, much less, the quality of the replacement parts. I have seen some used cars that had liquid stop leak in the tires and when the customer would complain, the technicians would balance the tire on the machine. When the tire was installed back on the car, it would be out of balance. (How bad out of balance, just depends on where the liquid wants to be in the tire while you are driving)!

Additional food for thought;

First, the brake rotor is an 11” dia., 20 lb piece of rotating mass that needs to be perfectly balanced. Most of the higher end rotors are very well balanced; however the ones on the lower end of the spectrum are not very well balanced, or even balanced at all!

Second, very few highways are perfectly flat and smooth; in fact, most have many high and low ridges built into them for the purpose of traction and water drainage. Very few struts are designed to give instantaneous rebound control. As a strut begins to wear, or loose some of the initial rebound control, the wheel begins to develop an uncontrolled bounce that can feel just like a tire out of balance.

Finally, very few service centers or “tire stores” take the time to install the wheels properly. When is the last time you saw the “technicians” install three lug nuts in a 10-2-6 o’clock sequence and progressively torque each one to 40-60-80-100 ft lbs (using a torque wrench) and then install the other two lug nuts, using the same torque sequence? It just doesn’t happen anymore, unless you do it yourself! All of them use air impact wrenches and hammer each lug nut until it stops moving. (Some of the smarter ones may use a sequential tightening method, using the impact)! Aluminum wheels, with the “mushroom head” lug nuts, are very unforgiving and sensitive to proper wheel installation and torque procedures. Rust on the rotors can even cause a wheel to be “uneven” when installed.

I have often wondered how my 92 PA (with 178K) could be so smooth at all speeds up to 100 mph. Could it be that I have fairly new Sensa Trac struts and Raybestos {super stop severe duty rotors}, or is it that I am so particular, I never let a technician mount my wheels and tires with an impact wrench?

By the way, when I need tires, I take the wheels off of the car and take them to the tire store to be mounted & balanced, then return home and mount them myself, using the installation & torque sequence mentioned above.

[polarzak]

I agree with you HotZ28; it is not a design flaw. My Lesabre ran as smooth as silk when new and up to 160,000 km. The problem only began initally when I had my tires rotated. Anyway, good news for me, my problem is fixed. Went to a different garage, and the mechanic decided to check the balance on the two front wheels. One was off enough to cause the vibration, and for me to see if the rebalance would do the trick before he would do the alignment. After reading your post about proper sequent and using a torque wrench, this fellow did just that. Anywaty, the car now rides like new.