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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: 1,724
    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: 1,724
    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.
  • quietproquietpro Posts: 702
    Most of the time, my transmission is shifting normally. The issue I'm having is sporadic. The hard shift from 2nd to 3rd seems to only happen when the transmission has cooled. On the way to work this morning, it happened during every 2-3 shift but if it continues as it has in the past, it may only do it a couple times when I drive it at lunch and on the way home. I didn't drive the car at all yesterday so it had about 36 hrs of down time. Throughout last week, I was driving it multiple times each day and only noticed it during the first drive each of those days.
    As for the slip, it seems to be subsiding and I may not have even noticed it if it were at this point when I first started driving the car. However, now that I have a heightened awareness of it, I notice even the slightest irregularity.
    Regarding my theory that this isn't mechanical, I'm working from the idea that if it were mechanical, it would be evident all the time e.g., if a gear was damaged, every time that gear was in use, the same noise/vibration/etc. would be evident. In the case of my car, sometimes it's perfectly normal and others, a little off. On that subject, I will be paying attention to the rear end/U-joint. I hear some clunks occasionally back there and won't let that go.
    With your issues, I would ask a technician to drive along with you and point out your problem to them as it occurs. Keep in mind that they are looking for obvious problems when you drop the car off and you are much more attuned to your vehicle so what seems blatantly obvious to you may be almost unperceivable to them. I can tell you that I had trouble getting most of my friends to notice the suspension problems with my last car. A couple more "car-conscious" guys knew exactly what I was talking about but even the "suspension specialist" at the dealership was unable to notice the problem. No doubt it's frustrating but try not to get too much into the thought that they are intentionally ignoring your problem. My advice would be to find ways to recreate the problem so that they are sure to notice it (a particular stretch of road, certain engine RPM or vehicle speeds, etc.). One last thing, are you talking about problems that occur when it runs in 4-cylinder mode? Or, did you mean that your car has the 3.6L 6-cylinder engine? The G8 has never had a 4-cylinder engine.
    One last thing, don't expect your rear-wheel-drive Pontiac to drive like a front-wheel-drive Honda. There are so many differences between the two that would always be evident...even if Honda built your G8. Different isn't always bad...sometimes it's just different. In my case, my Impala's engine seemed to idle smoother than the G8's. The transverse engine configuration of my FWD Impala made even the little misses in its idle much less pronounced. So, the G8 suffers from a rougher idle but it's nothing that warrants getting upset. :)
    Some folks drive themselves crazy over the little things if there car has any problems. It's mostly a perception thing...once you decide your car is of poor quality, ANYTHING becomes just one more thing that was designed/assembled/etc poorly. I've seen folks overlook big problems on a car they love and then ridicule someone else or their car because it was an "unfavorable" brand.
    My G8 isn't perfect but I love it. That may change over time but I don't see any indications of it. :)

    Have a great day and good luck with yours!
  • quietproquietpro Posts: 702
    If you're not happy with the red dash lighting of the DIC in your G8, I just discovered a company that offers to change the color of it and other dash lighting. The price is reasonable but I'm not sure it includes labor (they state that they disassemble the dash, recalibrate all gauges, then reassemble).

    Here's the link: page.tpl&product_id=48&category_id=18&option=com_virtuemart&Itemid=54&vmcchk=1&I- temid=54

    If anyone has any experience with this or something similar, please share.

  • bvdj84bvdj84 Posts: 1,724
    It crosses that line when it comes to the engine. I would say most people wouldn't still like the That is why I hate it, its the engine. If I wanted a used car with miles on it, I would have bought one. I lease, I shouldn't have to worry about it.

    I want to trade it and be done with it!! However I cannot get a straight answer on realistically upside down I am.
  • quietproquietpro Posts: 702 didn't answer the question about the number of cylinders but I'll assume you have the 3.6L V-6. The more I think about it, it sounds like your issues may be with the programming of the engine/transmission. Not necessarily that it's out of factory specs but that it could be improved by re-programming. I think it's what is affecting my car. Read my next post for the latest on mine...
  • quietproquietpro Posts: 702's the latest...hopefully I'm on to something...

    I was stuck in stop in go traffic yesterday and I noticed my car's transmission issue is occurring when I am able to move far/fast enough for the car to shift into 2nd gear or higher. At that point, when I came to a stop, the car was pushing very hard against the brake; when I released the brake, it would take off at approximately double the normal rate/power. If I then shifted to neutral and back into drive, the car would then act more "normal" and only creep forward when I released the brake. I repeated this several times so I don't believe it's a fluke and, hopefully, can repeat it for the service techs...or better yet find that it is a known issue and has already been corrected. It definitely seems like a programming issue or possibly a problem with some component that is sticking once the car has accelerated.

    I'll post an update if I can find anything. Anyone else heard of anything like this? I'm going to tap some of the other G8 forums as well. :sick:
  • quietproquietpro Posts: 702
    Latest...take 2...

    I found a TSB that addresses a rough 2-3 shift:

    TSB PIP-4395


    If you want to read more about it, run a Google search on the TSB and if you think it applies to you, take a copy to your dealer/service and have them check it out. I plan to. :)
  • rayainswrayainsw Posts: 2,955
    I had this condition addressed in my 2009 G8 GT.
    Seems that a keyword to emphasize here when describing
    the issue to dealer service people is:
    Good luck!
    - Ray
    Now at approx. 11,000 [s]miles...
    2016 BMW 340i
  • I recently purchased a beautiful liquid red Pontiac g8 3 months ago this is after
    winning an arbitrary with GM with an 07 Saturn aura XR. One of my main reasons
    for purchasing the g8 was the interior room and it was a completely different platform from the vehicle I was getting out of. Needless to say this gm producthas not been manufactured any better. Since purchasing this vehicle I have had 3 instances when there has been no throttle response when trying to accelerate. On the most recent incident while trying to merge on a major highway the check engine light came on 30 minutes after this episode. I drove it directly to the dealership where it had fault codes 11 and 21. These codes indicate there isexcessive movement in both banks of camshafts. My vehicle is now sitting at the dealership with the engine apart. Shims were installed on the right bank of cams and the left side they had to order a cylinderhead. Keeping mind this vehicle is 3 months old and 10000 km. After this I don't want anything to do with this car or any other gm product for that matter. I'm soooo pissed!
  • rayainswrayainsw Posts: 2,955
    Sorry for your troubles.
    I followed 2 Corvette specific boards for over 3 years,
    before & during my Corvette ownership -
    and now follow a G8 specific board -
    and I have never heard of a problem like yours
    in an LS2.
    Good luck!
    - Ray
    Many trouble-free LS2 miles...
    2016 BMW 340i
  • tayl0rdtayl0rd Posts: 1,926
    He doesn't have an LS2. Deducing from the lack of "GT" after the G8 and the mentioning of left and right bank cams, he has the V6. That said, I haven't heard of those issues from that engine. Then again, I don't follow it at all. I'm a V8 man. :shades:
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