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Pontiac Bonneville General Maintenance and Repair



  • evandroevandro Posts: 1,108
    I'm not sure it's the hubs. It seems to resonate only at 70MPH, give or take 2MPH. If it were the hubs, it would shake at pretty much any speed. Besides, it seems to shake only when coasting or when keeping the speed, for the vibration goes away uphill.

    It's indeed a very weird issue. Maybe it's a chassis thing, maybe a half-shaft thing, or engine mounts... I don't know, but I don't think that off-center hubs fit the bill.
  • bonnybluesbonnyblues Posts: 4
    I’ve been fighting highway speed vibration on a new 2002 SSEi with 17 inch chrome aluminum wheels since last summer. The vibration is noticeable above 100 kph (60 mph) and cycles from more to less over about a ½ km (1/4 mile). In some cycles the vibration is more severe and in others it is less severe. At times it almost goes away completely. There does not appear to be any variable that initiates the vibration or makes it any worse or better. The dealer replaced all the original RS-A’s, which were outside the road force allowance. The second set was also outside allowance and was replaced with ‘upgraded’ Michelin MXV4’s. Next, the lower A-arms with ‘better’ bushings were replaced. None of the above helped. The car was in the shop last week at GM’s direction to recheck everything. An on-car balance was attempted and failed to remove the vibration. The dealer suspected the left front hub was out of concentric and swapped in a new Grand Prix hub. He claimed this hub, with the Grand Prix 16 inch wheels eliminated the vibration (I never had the opportunity to confirm the ‘improvement’). However, the vibration returned when the 17 inch wheels were reinstalled on the Gran Prix hub (suspicion is that the low profile 17 inch tires are less pliable than the 16’s and exaggerate any vibration). The left front hub was replaced with a new OEM hub anyway. A recheck of the 17 inch combination showed maximum road force was only 4lbs (17 is considered acceptable). We await further advice from GM. It appears that the only thing that makes the vibration go away (according to the dealer) is to lose the 17inch tire/aluminum wheel combination. I ran across an SLE owner with 17 inch steel wheels with RS-A’s shortly after leaving the shop who reported no high speed vibration. Go figure!
  • evandroevandro Posts: 1,108
    But I'm still puzzled by the fact that it only happens when the engine isn't pulling. Or does it happen only in my SLE with 17" alloy wheels?
  • mlm4mlm4 Posts: 401
    On my 2000 SSEi the vibration is most noticable at highway speeds but the range is greater -- more like 55 to 75 mph. Also, sometimes I can feel a wobbling at low speeds between 10 and 25 mph. That makes me think tires, but I still have the factory originals because I'm not convinced spending the money to replace them will fix this problem. I can't rule out that the hubs are also part of the problem, because it's likely being caused by an interaction of several components. The tires might be amplifying the problem, if anything.

    The curious thing is that late last year I rented a low-mileage Bonneville SE with the standard 16" tires and it had the same vibration as my SSEi, so I believe it is not just a tire/wheel problem.
  • shaky1shaky1 Posts: 1
    I have a 2000 SE with 16 inch wheels. Had the Firestones replaced with Michelins. Had the forced balanced done. 1 new rim. Tires rebalanced and it shakes just like the day it was bought! Has 14000 miles and 4 months warranty left.I will be there everyday till the end!
  • p100p100 Posts: 1,116
    Inner CV joints on your axles, when defective, will cause unpleasant vibration that is primarily felt in the floorboards of the car and possibly shaking of the hood. This is what was happening to my Mazda before the axles were replaced. My Mazda is a V6 with a 5 speed manual. When accelerating hard and shifting at high RPM like 6K (the redline is 7K RPM), there would be serious vibration in the floorboards and the steering wheel and would go away when I let up on the gas. The car would also vibrate in the front floor boards at cruising speed of about 85-90 MPH. When this first happened, the car only had about 300 miles on it. I took it back to the dealer, and they checked the balance on the tires. All zeroed out on their balancer so they were balanced correctly at the factory. They told me some nonsense about this vibration being a common thing on front wheel drive cars and that was that. Well I did not give up, went to another dealer and this one confirmed that they have seen several of these cars with defective front axles and CV joints causing very unpleasant vibration. I had all axles and CV joints replaced, which eliminated most of the problem. Then I had the defective front left hub replaced. With the defective hub on I noticed some wobble and shudder upon braking at high speeds, but this was not consistent. New hub totally eliminated that. I believe that some manufacturers nowadays are using cheap axles and CV joints. I talked to several mechanics who confirmed that even on some Toyotas this is a problem.

    Vibration can be also caused by axles shafts that are slightly bent or out of balance. An axle support bearing with damaged rubber bushing (if it has one) could also cause vibration. Such bearings are used on RWD car and truck driveshafts and have been known to cause vibration when the rubber bushing deteriorates or gets torn.

    Tire balance:
    This is a problem, and a big one in this country. It is virtually impossible to find a place that will balance your tires correctly: I am on the verge of buying my own balancer because I cannot put up with having my tires balanced wrong over and over again. I have seen two different people use the same machine on the same wheels and come up with completely different results.

    First of all, standard US wheel weights are made in 1/4 ounce increments, or 7 gram increments. If one balances tires correctly using a balancer that rounds off to the nearest 1/4 ounce, it will be only marginal on an average passenger car. I had this done on my 98 Nissan Maxima using a Hunter $ 12,000 state of the art balancer. The balance was OK, but not perfect and I could feel very slight shudder around 85 MPH. Metric weights come in 5 gram increments, or about 1/6 ounce. This resolution is much better, so my advice is if you want better wheel balance go to a place that uses 5 gram increment metric balance weights and has their machine calibrated to the nearest 5 gram roundoff mode. I found this to be far better than balancing with 1/4 ounce weights.

    I checked out the specifications on many electronic balancers and their capabilities. Some machines made by Beissbarth, for example, have capbility to go to 0.1 ounce and 0.05 ounce resolution! This is 2.8 grams and 1.4 grams!!!! The problem is nobody makes standard weights in those increments. When balancing tires for auto racing they recommend accuracy to at least the nearest 0.1 ounce (2.8 grams) and using flange adapters in the wheel lug holes instead of the centering cone on the balancer. How many places that you have seen use flange adapters to mount the wheels on the balancing machine? And who will bother to make custom weights to fine balance your tires? Most modern balancers are capable of far better resolution than +/- 7 grams or +/-5 grams.

    Finally, tires. I never would have believed it if I did not experience this myself. Some tires sold are absolute junk. They take huge weights to balance properly (like 2 oz on each side) and on some belts will break in a short time. Broken or damaged tire belt will cause all kinds of unpleasant vibration, and the longer you drive the worse it gets. I had this happen with Continental Conti Touring tires (these were US made). These tires were junk. I bought two new ones to replace the half worn one with the broken belt, and both new ones turned out to be completely out of round and caused terrible vibration around 70 MPH. I jacked up the front of the car so that the tires were almost touching the floor and these tires were egg shaped when spun. The tire seller refunded my money on these but not the postage - it cost me $ 40 to pay postage for two tires two ways. I replaced all four Continentals with Michelin Pilot tires and peformed the same test. These tires were as round as they could be.

    Mounting four Micheline Pilot tires, balanced to 5 gram roundoff using flange adpaters on a good quality balancer, made all the difference in the world on my Mazda 626. Most vibration disapperared. However, about 25 K miles later and rebalancing of tires, I get some slight vibration at 80+ MPH that comes and goes. Probably lousy inner CV joints acting up again.

    A defective or damaged front strut could possibly cause vibration as well, because it is the strut that determines and maintaines front wheel alignment, and a worn strut will cause wheel hop, which will translate as vibration as well.

    I hope this will help somebody to solve their vibration problem.
  • imidazol97imidazol97 Crossroads of America: I70 & I75Posts: 17,702
    I had an 80 Cutlass with tire and balance problems. Original tires were replaced with something called T/A. Don't remember the company. Factory rep wanted ram-tested tires put on. Didn't happen. 50K I noted the balance seemed only with tires more out of round when on front.(I used a dial indicated to check tread runout supporting A-arm with scissors jack.)

    Bolt patterns were off center; combined with minimal runout in tire/rim caused problem sometimes that came and went, just like talked about here.

    Balancing comment: New tires on 16 inch rims on LeSabre. Dealer has new force balancer. Cleaned up the Michelins right now. I had some balance problem at certain higher speeds. Service manager suggested coming in right away for force balance because of problems with Parks and Cadillacs like you're talking on Bonneville. He said they were replacing tires on those with Michelins because of least trouble compared to other original equipment tires. When I told him mine already came with Michelin Symmetrys he was surprised I had any highway vibration (at 1300 miles). My experience with lots of Michelins (10 sets maybe???) is that new tires always need rebalancing after 500 miles or so; then they act like they will the rest of their life, well-balanced or a problem tire.

    Never buy tire store tire when that model/size is used on new cars. I think that best ones go to the manufacturer and the culls go to the stores... Replaced originals on 89 century with same brand and tire that were nonMichelins because of great tread and grip and life. They shook; dealer didn't question me or try to rebalance, he just sold me the Michelins I wanted for the difference. He knew there were problems with those tires I had bought. The Continental story doesn't surprise me -- isn't Continental owned by Michelin now??? like Goodrich, and several otheres. I saw a chart at Tire Discounter store that listed who made all the brands they sold.

    My suggestion would be for the dealer to put on tires from a car (new?) that does not shake. Maybe fronts first, then add rears, to see if the tire/rim is the problem. Then try your wheels on the other car, to see if the shake moves with the tires/rims that you currently have.

    My service manual for 2003 LeSabre has a long check list for vibrations, including the bolt pattern being offcenter. That wasn't in my last 98 LeSabre manual. It's an indicator of where GM is finding problems.

    This message has been approved.

  • mlm4mlm4 Posts: 401
    I'm in total agreement about the balancing. The same dealer (different techs) balanced all four wheels twice, the first time rebalanced all four, and the second time he found one wheel out of balance. A couple of the wheels have huge weights on them too. But even after all that there was no noticable difference in the vibration problem. Because it phases in and out and occurs regardless of engine load or braking (it's purely speed dependent), I still think it might be the stud runout out of spec. Also, since my car is driven less than 4,000 miles per year, maybe the tires are flat spotting too. I can't say for sure that the vibration has gotten worse since the car was new, but it seems like it has, although in the past year since I have really been paying attention to it it seems about the same.
  • stanm1stanm1 Posts: 2
    Help! My 2000 SE looks like a cat in heat!

    The load leveler has gone whacky and pumped the rear shocks up to maximum. Looks pretty silly I must say. My guess would be that the load level sensor must be out to lunch, as the compressor motor sounds as though it is functioning normally. My question is, does anybody know where this sensor may be located? Just wondering if I can troubleshoot it myself as I really don't want to fork out the $$$ right now to have a garage fix it.

    Any ideas or tips?
  • alcanalcan Posts: 2,550
    Automatic Level Control Compressor
    Under the right rear of the vehicle, near the rear suspension carrier
    Automatic Level Control Accessory Inflator Switch
    Inside the rear luggage compartment

    Automatic Level Control Exhaust Solenoid
    Under the rear of vehicle,near the ALC compressor assembly
    Automatic Level Control Height Sensor
    Under the left rear of the vehicle, near the rear suspension carrier
    Rear Fuse Block
    Left rear of the passenger compartment, under the rear seat cushion

    Rear Integration Module (RIM)
    Behind the rear seat cushion (upper,left)

    "The suspension position sensor is a potentiometer which detects height changes at the rear of the vehicle and, in turn, relays these changes to the RIM, which controls the functions of the compressor and exhaust solenoid. To prevent energizing the compressor relay or exhaust solenoid during normal ride motions, the RIM provides a calibrated delay before ground is completed to either circuit.

    The sensor is mounted to the left rear side of the rear suspension support assembly. The actuation arm is attached to the left rear control arm by a short link."

    Make sure the link from the sensor to the control arm isn't disconnected. If ok, a scan tool is required to diagnose the system.
  • bigred00bigred00 Posts: 13
    The Stablity Control System on my 00 SSEi just started acting up too. Twice, out of the blue, it has recommended that it be serviced. The warning does goes away with a re-start. A quick trip to the dealer determimined that it is related to the steering sensor for the magnasteer. Has to go back for further analysis. Car has 46,000 miles on it.
  • zzoom1zzoom1 Posts: 31
    I have a 2001 SE model which needed a new intake manifold at about 23,000 miles which was covered under warranty. Dealer service rep said that there has been no redesign of this part, same plastic junk as before. When I bought the Bonny, I had always heard that the 3.8 series II v-6 was a great engine. Now I'm starting to wonder. It seems like it's not a matter of if, but when the intake manifold goes. Has anyone out there NOT experienced this problem? The reason that I ask is I've found a 98 Bonny SLE with 33,000 mile on it which I'd consider for my work car, it's condition is excellent, and the price is very fair, but if the engine blows????
  • mfahey1mfahey1 Posts: 419
    One way to look at it is to point out to the seller the nearly guaranteed intake problem and then devalue your offer accordingly, much like the late 80s to mid 90s Chrysler vans with their transmission problems. If he doesn't take, oh well.
  • montanafanmontanafan Posts: 945
    GM redesigned the lower intake manifold for the 1999 model year and hasn't had a problem with the upper or lower manifold since. There are gasket leak issues with the 2000 thru 2003 Bonnevilles.
  • Sorry it has been so long since I have written guys (my last post was in the 700's somewhere). I finally put my 95 SSEi in the shop 2.5 months ago after it developed an oil leak as well as the numerous problems it had before. I took it into the mechanic and when he asked me what I wanted him to fix on it I just simply said "whatever's wrong with it." Well that has been 2.5 months ago and the mechanic and I have gotten to be pretty good pals since then. After replacing almost everything electronic on the car (even the main computer) he is starting to rebuild the engine. Just wanted to give everyone an update on how this poor little bonne is doing. I have a feeling after I get her out of the shop it will be time to trade her in. I have my eye on a Buick Regal right now.

  • mlm4mlm4 Posts: 401
    Today the sunroof on my 2000 SSEi ate the black plastic pop-up air deflector while it was closing. It had been starting to bind on the left side recently and I could see where it was rubbing and binding. I had meant to lube it (although the area that was rubbing never had any lube on it) but never got around to it. There's a rib that is flat on top above the track where the sunroof slides over the deflector and pushes it down, and the left one (the one that was binding) went CRUNNNCH! and broke off. After this happened I decided that it would be necessary to hold the deflector down with my fingers while closing the roof. Then it caught the right side and went CRUNNCH! and broke that one too.

    Interestingly, it now seems to work better than it did before I busted it. I'm thinking of just lubing the jagged edges and hoping for the best, but I've got a part number request into GMPartsDirect to see if the deflector can be replaced separately. Does anyone know if this is possible? It looks like it snaps into a hinge on each side. If not, then it looks like the entire track assembly will have to be replaced, because the hinges are rivet mounted to the track.
  • alcanalcan Posts: 2,550
    Removal Procedure:

    Cycle the sunroof glass panel to the rear.
    Push down on the right front side of the wind deflector.
    While holding the right side down, complete the following steps:
    Push the left front side of the wind deflector towards the right side.
    Pull up on the left side until the lower tab clears the roof opening.
    Swing the wind deflector in an upward arc, rearward, in order to disengage the wind deflector from the hooks on both sides of the sunroof module.
    Remove the wind deflector from the vehicle.
    Installation Procedure:

    Engage the rear of the wind deflector into the side hooks on the sunroof module.
    Arc the wind deflector in a forward motion.
    Push the right side of the wind deflector down into the roof opening.
    Push the left front side of the wind deflector inwards and down so the tab clears the roof opening.
    Close the sunroof glass panel.
  • mlm4mlm4 Posts: 401
    Thanks. When I got home I looked up the procedure in my service manual. Looks easy. Got the part number, list price is $68.19.

    The deflector broke into two clean pieces (one on each side), so I superglued them back on. I doubt it will hold, but it's worth a try (at least until I order the replacement part). The plastic has a textured surface, so it's no wonder that the panel doesn't glide smoothly over it. Here's the left side, with the broken piece glued back on:
  • lash92sseilash92ssei Posts: 35
    I have a friend that lives overseas. Does anyone know of a parts store that ships overseas?
  • clipper52clipper52 Posts: 1
    I had a 2002 Bonneville that I had vibration at highway speeds the day I left the dealership. I was back fiur times with no luck to which I went to the lemon law. Gave them one last time to fix it. They re-balanced the hubs but it did not completely fix the problem. At that point I went to arbitration and guess what, the system works, BBB forced GM to buy the auto back and I am now the proud owner of a 04 GTP...

    They offered to put new tires on due to the recent release of TSP..check it out..

    Man am I glad to be out of that car..
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