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G8 Problems

pfwizpfwiz Posts: 6
I have had my G8 (V6) loaded, for just over 1 month and about 1000 miles. It is currently in the shop for the second time for vibrations and brake pulsations. The first time they put a set of new front tires on to fix the vibration. That didn't work. I just got off the phone with the dealership. The said they cut my brake rotors down to fix the brake pulsations.
QUESTION - is cutting the rotors on a 1 month old, 1000 mile car the right way to fix this issue. Is it me or should I expect them to replace the rotors? The dealership told me GM will not cover replacing the rotors... Is this the truth??

If anyone can shine any light on this I would greatly appreciate it.


  • Three black hard-plastic interior trim covers on my new G8 just FELL OFF today. Two were held on by little white pushpins and one has molded tabs. WTF!
  • bvdj84bvdj84 Posts: 1,721
    Well, GM has to save money some how.... they have to sacrifice
  • pfwizpfwiz Posts: 6
    My G8 has a vibration problem.
    It has constatant light to medium vibration most noticible at around 68 mph. Sometimes you can see the the steering wheel buzzing and you can feel the vibration strongly thru the shift nob.
    I took the car to my dealer at about 1400 miles, they road force balanced the tires and then put 2 new front tires on the car. This did not help much in my opinion.
    I took the car back to the dealer at about 1800 miles. They road force balanced the tires again and indexed the drive shaft. This did not help significantly.
    I then made arrangements to test drive my car with the service manager. After driving with me, the service manager agreed my car has a noticible vibration. We then drove a different new G8 off the lot that had the same equipment as mine. Guess what? THIS G8 VIBRATED AT LEAST AS BADLY AS MINE! The service manager then promised to call Detroit to find out what else he could do.
    Two days later the service manager called back. He had talked to "Detroit" The answer was there was nothing else he could do. G8's JUST VIBRATE!

    Next I plan to call GM directly... Lets see if this works any better.
  • xrulingxruling Posts: 4
    19" wheels/tires? They need to be road force balanced.
  • pafromflpafromfl Posts: 47
    My G8 has a vibration problem. It has constatant light to medium vibration most noticible at around 68 mph.

    Try putting the car in manual mode. This will disable AFM (DOD). You may be sensing the vibration of the effective 3.0 L 4-cylinder engine. After I installed a Magnaflow cat-back system and before I disabled AFM, my rearview mirror would vibrate enough to blur the view.
  • NHTSA recalls all Pontiac G8s

    Pontiac and the National Highway Traffic Safety Administration have announced the recall of 35,038 G8 sedans for two separate issues. General Motors announced earlier this year that the Pontiac brand would be killed by 2010, with the G8 set to ride off into the sunset by the end of the year.
    According to the NHTSA’s Web site, the Pontiac G8 is being recalled for a brake light issue and a potential problem with the vehicle’s tire pressure monitoring system. The recalls cover all G8s from the 2008 and 2009 model years.
    Some G8 vehicles may have been equipped with an incorrectly programmed brake pedal position switch from the factory. The defect can lead to the continual illumination of the car’s brake lights, giving other drivers on the road little warning when the vehicle is coming to a stop. Due to the increased risk of crash, Pontiac dealers will begin fixing the problem June 5th.
    The G8’s second recall involves the vehicle’s tire pressure monitoring system. Some vehicles were equipped with the wrong programming, which could give false tire pressure readings. As a result, the system may not warn the driver when tire pressures fall below safe levels, potentially leading to deteriorated handling or even a crash.
  • wigtwigt Posts: 6
    09 G8GT
    I have had the vibration problem too. They replaced one of my tires. It helped. Sometimes the steering wheel has a vibration to it and sometimes not. IIt is different then the slight vibration you feel in the car when it goes into 43 cylinder mode. I have 2800 miles on ours.
  • geeeightgeeeight Posts: 2
    2009 G8 GT: Well after 2800 miles the turn signal seems to get stuck on and the repeater will not turn off automatically. I am waiting for the dealer to "contact the engineers" for a solution. My guess is either the cam or switch is starting to fail. Started to be an issue with wide turns to the left. It is now sporradic on the right turns as well and tight turns. Seems to be worse when the car is hot from sitting in the sun. Only started to happen about a weeks ago (around 2600 miles).

    Anyone else have this problem or recommended solutions?
  • 23109vc23109vc Posts: 218
    this is why no matter how well the G8 performs - I don't think I'm going to buy one. When you consider the quality issues AND you factor in that Pontiac is dead, and GM is having it's own problems - do you REALLY think you're going to get quality customer care AFTER you buy it?

    they will tell you what you want to hear to get your money - once you have the car - you will be on your own.
  • camydogcamydog Posts: 64

    It may be a software issue. I know that sounds funny but many of the controls on the new cars are not governed by the typical timer or PCB anymore. My hope for you is that there is a TSB that applies, and that it is a programming issue.

    Good luck.
  • geeeightgeeeight Posts: 2
    Issue fixed. There was a small plastic clip that snapped in the collar and allowed the turn signal stalk to shift outward. Item was on back order and was fixed. Dealer has been great about the issue and put a temporary fix in place while waiting for the part.

    The part was probably damaged during factory installation and just worked loose over the short driving time.

    Love the car. Simple to fix took a while to diagnose and get the parts into the dealer.
  • p100p100 Posts: 1,116
    This is my dilemma exactly. I like the G8 but I do not trust GM quality control and I am rather disappointed to read things like vibration issues with these cars.

    BTW, if rotors pulsate on an almost brand new car, they should be replaced. It means that they are cheap rotors and they are getting warped. If you turn cheap rotors like that , you remove more metal and make rotors more susceptible to warpage.
  • pafromflpafromfl Posts: 47
    BTW, if rotors pulsate on an almost brand new car, they should be replaced. It means that they are cheap rotors and they are getting warped.

    I've had a couple new cars that sat on the lot a long time. It took about 1500 miles before the brakes completely stopped pulsating. I suspect an uneven rust pattern on the rotors. These cars spent some time at sea and parked at a port, so salt air might be the culprit.
  • quietproquietpro Posts: 702
    Defective rotors, workmanship, etc. is not a GM exclusive. I've ridden in many cars with bad rotors. It happens...for many various reasons...but GM has always taken care of me and my family.

    I've driven four G8 GTs to date and only one has had a brake issue...the one I took delivery of. Lucky me, huh? :) But, I'm more than confident that my issue will be resolved to my complete satisfaction. As stated in a previous post, I suspect my problem is also due to rust on the rotors (they aren't warped, they're rough).

    Perhaps I'll be proven wrong, but I think I'm going to be a very happy owner. If, after the dealer has had the chance to fix my issues, I'm not satisfied, I'll definitely report back. I'm very "picky" but have been happy with my last two GM cars.
  • quietproquietpro Posts: 702
    Anyone have an issue with the transmission on their G8 GT? I've driven a few and the one I own has a quirk that happens about 50% of the time.

    The problem is that during some stops or slow-downs (bringing the car to 1st gear), the transmission seems to delay for a split second, causing an abrupt start or jerk. When this behavior is displayed in 1st gear, the shift from 2nd to 3rd seems to also be rough (slow shift followed by abrupt surge).

    I've talked to my bro-in-law who owns a transmission shop and he agrees that it probably isn't mechanical. He says it's more likely a firmware glitch that can be easily fixed by flashing (very common, he says).

    This is a minor nuisance, the type of issue many would not really recognize as an issue but I figured I'd ask and see if anyone else has had any experience with the problem.

    Thanks! :) :sick:
  • wigtwigt Posts: 6
    I have had this happen sometimes too. I haven't connected it to the harder shifts that sometimes occur. I have had mine for about 4000 miles and will bring it up when it is oil change time. Usually the tranny shifts very smoothly in either regular or sport mode, it is smoother with a slightly heavier foot. On the abrupt starts it is like the engine revs a bit, if the foot wasn't on the brake it may jump forward a little. It doesn't last but a slit second when it does it.

    I love the car though.
  • quietproquietpro Posts: 702
    It sounds like you're experiencing the same thing. The rough 2-3 shift is almost always when the car is cold or after it has sat and cooled for a while. I'm trying to isolate both as much as possible because I know these are going to be "can not duplicate" issues unless I get "lucky." If I find the trick to making the G8 misbehave, I'll share with the group and maybe y'all can try it on yours.
    Here's another observation (definitely not a problem). I've noticed that occasionally the car seems to drag as if it were a manual transmission left in gear while other times, it coasts more like what I'm used to with other automatics. Does anyone have any info on this? I haven't played with the manual shifting yet (still in break-in) but I'm thinking this is a computer programming "issue" if anything. However, when the car seems to be coasting more freely, that seems to be when I get the "slip" I'm noticing. Otherwise, it's almost like I'm power-braking as I slow to a stop and even while stopped. I've even noticed (occasionally) when I have that feeling of power-braking at a stop, if I slip the trans into neutral, the car will still lurch forward (slightly) when I release the brake. It's as if the trans has stored energy/pressure that isn't released until it moves.

    Sorry for the rambling. As stated before, I haven't been able to lock down the particular conditions that are causing this inconsistency with my G8. But, I do appreciate your input. It will help me figure this out eventually. :)

    Have a great day,
  • It’s funny how one small event can turn you from loving a car to wondering if you made a big mistake. Yesterday I pulled out of a parking spot and heard a loud grinding noise. A couple of times the low front dam has scraped across a concrete bar, but this was LOUD. I got out and sure enough, the right side of the front facia was dangling. It would not “snap” back into place. I drove (slowly) direct to a nearby Pontiac dealer’s body shop. They said the facia broke away as it’s supposed to, to avoid greater sheet-metal damage. They said all I would need is a new facia and new lower cover panel…painted & installed about $2,000 and 2 days, could I bring it in Monday? S**t. I told them to patch it up as best they can without the new facia. They said OK, about $600-$700, bring it in Monday. I asked them to put it together now as best they can so I can get down the road, which they did at no cost (bless ‘em). Unfortunately body parts will only get more expensive and less available for the G8. Lesson learned: do not to pull a G8 very far into a parking spot with a concrete bar across the end of it. :cry:
  • camydogcamydog Posts: 64

    Check out the transmission section in the owners manual. It references the engine braking you are writing about. My car seems to coast more in auto mode, and engine brakes more in sport mode. The manual says it's to help slow the car and keep the brakes cooler.

    Hope this helps.
  • bvdj84bvdj84 Posts: 1,721
    Well, I have a similar issue, but on my 08 G6, 4cyl!! When shifting in gears, 2-3, it seems like it slips, abruptly moves into the next gear. Also when it is done moving into the gear, it sorta drops in power, you'll have to push down a bit harder.

    Normally, you should push down and it should be a consistent line of power up the band with no falling power gaps in that band. Also, a good engine, coupled with a good transmission, you really should feel the transmission shifting, and is also coupled with the smooth, solid power band. My 06 Accord had a nice line of power, no falling gaps. It was also more predictable. Its as if the adaptive programing is too sensitive.

    I have taken it several time to the dealer. No duplicate issue!

    Now, I think this might be an issue in general with GM, as I have seen other GM forums with similar issues.

    How you are you so sure that its not mechanical? The programmer controls when it shifts, but not really how well it shifts, meaning how it feels physically. ??

    I have just learned to live with it. I know its not normal. I guess, I will wait for it to become more consistent, If it does at all? It does not happen all the time, but enough for me to know its happening.

    For all the above issues, I hate the engine! It makes it feel like it has many more miles on it than it does.

    I have made Pontiac aware of it, my dealer, and yet they are not real motivated. I am just tired of leaving my car there and get no duplicate.
    They'll honor the warranty, which is about $1,500 in bills already.
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