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GMC Sierra: Problems & Solutions



  • 0patience0patience Posts: 1,542
    These are some information on a couple things I read thru the posts and saw that may interst some of you.

    Driveline Vibration/Growl Noise (Reprogram PCM) #99-07-30-024
    Driveline Vibration/Growl Noise (Reprogram PCM)
    2000 Chevrolet and GMC C/K Utility and Pickup Models (Silverado and Sierra)

    with 4.8 L or 5.3 L Engine (VINs V, T -- RPOs LR4, LM7)

    and Hydra-Matic 4L60-E Transmission (RPO M30)

    Some customers may comment about a driveline vibration/growl noise at speeds between 56-80 km/h (35-50 mph) with low engine speeds.

    Engine torsional vibration when the torque converter clutch is engaged at low engine speeds, 1100-1400 RPM, can excite various driveline components. These driveline disturbances can cause noises and vibrations that the driver may feel and/or hear.

    Reprogram the Powertrain Control Module (PCM) with the calibrations listed in this bulletin.
    Front Suspension Coil Spring Noise (Install New Coil Spring Insulators) #99-03-08-002A
    Front Suspension Coil Spring Noise (Install New Coil Spring Insulator)
    1999-2000 Chevrolet and GMC C/K Models (Silverado and Sierra 2WD 1500 Series)

    Some owners may comment about front suspension noise. The noise may be described as a "bong" or "clunk" noise. The noise may be more noticeable when driving slowly over bumps or backing the vehicle out of a driveway.

    The front coil spring contacting the frame may cause this condition.
    A new front coil spring insulator has been developed to correct this condition. Install a new insulator (1) to the top of both front coil springs.
    Steering or Front End Road Induced Vibration (Install and Reinforce Revised Steering and Suspension Components)
    1999-2000 Chevrolet and GMC C1500 Pickup Trucks (Silverado and Sierra)

    Built Prior to the Following VINs
    Body Series

    Fort Wayne, IN



    Pontiac, MI


    Oshawa, ON

    Canadian dealers require PRIOR District Service Manager approval to apply this bulletin.
    Some customers may comment on a steering wheel or front end vibration.
    Several components in the front end steering and suspension work in unison to isolate the driver from road irregularities and from road/tire induced vibration. If any of these components are not working effectively, it will affect the other components of the suspension and steering system. Tire and road vibrations may be transmitted to the passenger compartment and steering through the rack and pinion unit. Additionally, the mounting points of the steering rack on the front frame crossmember may be amplifying any road vibrations.
    In order to dampen unwanted vibration from the steering wheel, the following revisions must be performed:

    The tires must be in accordance with Corporate Bulletin Number 99-03-09-002 published August, 1999.
    The steering rack must be replaced with a revised rack.
    The left front steering rack mounting point must be reinforced.
    The lower control arms must be replaced with units incorporating a revised bushing.
    The power steering (PS) pump metering valve must be replaced with a revised fitting.
  • obyoneobyone Posts: 8,065
    replace the rack and pinion TSB. Can you imagine having to change your rack and pinion on a new truck. You would think it's grounds for buyback wouldn't ya. BTW, it's works 50% of the time or less as ths owners who have done it have pursued buyback as it didn't really solve the front end/steering vibration.

    The first TSB to reprogram the PCM can be called the solution for the driveline growl. You can find the updated software solution by going to this site and entering your VIN.

    BTW, the recalibration doesn't work either. All it does is force the truck to downshift faster when depressing the gas pedal. The truck will still lug and cause the driveline growl at 38-42 mph.

    How do I know all of this......been there done that. And yes, you do need the GM district reps approval to change out the rack and pinion which BTW, is harder than pulling your own teeth.

  • jsmisekjsmisek Posts: 16
    Hey guys, I finally had my wheels and tires performance balanced on a hunter machine. Two of the four rims and tires balanced out great. One of them balanced out so-so, and one of the rims and tires would not balance out at all. The dealer tried spinning the tire on the rim and other methods, but could not quite get a true balance. The tire store that sold the rims and tires to the dealer put the same defective rim and tire on his machine, and it showed that it was way off. The tire store wants to try a hubcentric adapter on the wheels I have to see if the vibrations go away. If this does not cure the problem, he is willing to let me select a new style of replacement rims. I told him I was tired of "jacking around" with this problem and would like to get different rims because I have a defective rim. Anyway, the adapters are on order and should be here on Thursday. I do not feel this will cure the problem, I still have one rim and tire that will not balance out! I will keep you informed on my progress.
  • sujersujer Posts: 2
    the vibration starts at 62 mph thru about 75 mph, also tires & rims were balanced on a hunter foced balancer
  • obyoneobyone Posts: 8,065
    i would look at getting rid of those tires. The sidewalls are totally flimsy as compared to other brands, not to mention the lightness in weight of the tire.
  • jdgoatjdgoat Posts: 19
    After reading through all the posts it appears I have the infamous tapping problem with my 5.3. Any suggestions on what I should do next with my dealer who claims it's normal for the truck? I have 24,000 miles on the truck. Since there is no fix should I request a certain service or ask for a longer warranty? I'm in the dark on the next step to take, if there is a next step. Thanks for any help.

  • nerdnerd Posts: 203
    My '00 Sierra has the same problem. The dealer said the sound is due to piston slap caused by a piston design flaw. He said that GM plans to provide new pistons beginning early next year and that the dealer will install them in the engine. (Ford provided new or remanufactured engines when they had the problem). I don't plan to accept this option since I don't believe a dealer has the tools and expertise to do the job well.
  • obyoneobyone Posts: 8,065
    from what I understand they won't be coming out with new pistons. Nor will they do anything about it, cause "all the trucks do it". So, jdgoat, do you have it documented as to what GM plans to or not to do about your problem? given them any opportunity to correct the problem? Cause, for one, you need to have it identified by the dealer and give them the opportunity to repair it. If the deny any problem exists, then proceed directly to BBB online and file a complaint against GM. You will get a phone call from a guy in Florida whose name I'll omit for now and he will tell you that under no circumstances would GM buy back the truck (it's what he's paid to do).

    The BBB will contact you and ask if you would settle for anything less than and outright buyback. At that point, you may ask for the extended warranty as a negotiating point. GM will ususally agree at this point cause it really costs them nothing but paper to give it to you.
  • volkejvolkej Posts: 108
    obyone - The service advisor at the dealership where I had the problem diagnosed told me the likely fix was to change the pistons. It was written on the service order that the problem existed and that a change was in works - probably 4 to 6 months.
    It may be a rumor, but some Chevy dealerships are acknowledging the problem in writing.

  • obyoneobyone Posts: 8,065
    I wonder how do you go about determining that it is the piston and what piston are they about to change to? Time will tell on this one. What do you feel about your dealer tearing your motor apart and replacing your pistons when simple things cannot be verified. Is this a can of worms, a nightmare waiting to happen?
  • gator36gator36 Posts: 294
    Just back from the Dealer.

    Talked with the service manager regarding the piston slap.
    Apparently GM has 500 sets of pistons that are .00025 of an inch
    larger than the originals in field tests around the country.
    If there are no issues with these GM is planning to release
    this as a fix in spring of 2002.

    That is what I heard... Don't shoot the messenger.
    Personally, GMPP and a little piston slap for me..
    I don't want some tech learning on my engine..

    This Service Manager was very knowledgeable.
    He does know his sh** and is working on the A/C
    issue I have seen in the 2001 Silverados.
    (More on that later)
  • modvptnlmodvptnl Posts: 1,352
    ......motors in my time. EVERY one of them I've bought the pistons first and had the block bored to fit the pistons. I can't see how GM can supply one size fits all piston on a motor that has been run for any significant amount of time.

    TWENTY-FIVE ONE-HUNDRED Thousandths of an inch(.00025) is not going to do ANYTHING if the bore is .001 of an inch larger than when new. Most oversized pistons come in .020-.040" over. (big blocks I've seen up to .060 over)
  • jdgoatjdgoat Posts: 19
    I definitely don't want them tearing into my engine to replace pistons. I could obviously live with the knocking on startup, but an extended warranty if future complications arise would be nice. However I may not have to pursue that avenue as driving home the other day my Service 4WD came back on again. Placing it in 4WD I noticed under no load(coasting) my brand new transfer case has started squeeling and growling. This is the 4th time in with my 4WD problem. Seems like the new transfer case they installed last time went bad(or the installation did). Thanks for the info. on going to the BBB. I think this may be my next route at least for my 4WD problem.
  • volkejvolkej Posts: 108
    I paid a lot of money for this truck and I'm not particularly happy that they are talking about rebuilding what is essentially a new motor.
    I haven't decided on a course of action yet, but I don't think new pistons are the answer.
    Off the top of my head I'm thinking new motor if I keep the truck, if not that then maybe it's time to visit a Toyota dealer.
  • gator36gator36 Posts: 294
    Just thought I would put in my .02

    I just traded in my 97 GMC Sierra.
    It had 150,000 miles on the motor, all by me.
    Motor work done during the life:
    Oil Changes Regularly (A couple were overdue)
    Belt tensioner at 90,000 miles
    Plug Wires
    Intake gasket at 126,000 miles.
    This motor had the piston slap from (at least when I paid attention)
    about 20,000. Who knows it could have been longer.

    All I know is, piston slap or not. The motor was
    running like a raped ape at 150,000 miles.
    I traded the truck in on a 2001 model and I love it.
    During the life of that 97 Vortec motor. I never
    saw any metal in the pan on oil changes.
    At 150,000 miles it burned ZERO oil.

    From several people who are in the business to know,
    I have heard that the loose tolerance on the piston
    skirt was designed into the engine. The purpose was to gain engine life and reliability.
    As I understand it, GM is working on a "Quiet" fix
    for the piston slap to pacify the owners who
    cringe everytime they hear the noise.
    Personally after 30 secs or less there is more
    vibration and noise coming from the A/C compressor
    than anything else in the engine bay.

    As my previous truck would attest to. It was bult
    well and will continue to for someone else.

    Not to offend anyone, but, we are not driving a
    Cadillac or Lexus here. It is a truck!
  • ryanbabryanbab Posts: 7,240
    i take your side

    Thats exactly how i feel.
  • jlflemmonsjlflemmons Posts: 2,240
    On startup, an Indy engine is loose as a goose. Noisy, blow by, the works. Same with a stockcar engine. Reason being that if you build it tight you will get even tighter as things heat up. I am happy with my 6.0L, it does rattle a little bit when first started, but uses no oil and runs like a spotted ape. If it gets bad before the warranty is out, I will go talk about an extended warranty. Otherwise, I'll just keep 'er greased, oiled, gassed, and running down the road.

  • obyoneobyone Posts: 8,065
    What is the difference between running like a raped ape vs. running like a spotted ape? I personally don't care for apes as they remind me of some off brand truck drivers...the ones that insist that their trucks are full sized. Or was that baboons that we were talking about?
  • modvptnlmodvptnl Posts: 1,352
    Well if you don't mind your motor running 500 miles between rebuilds, go ahead and build 'em that way. LOL!!

    "From several people who are in the business to know,
    I have heard that the loose tolerance on the piston
    skirt was designed into the engine. The purpose was to gain engine life and reliability"

    See, Ford had it right in the first place!!!! Youz guys bust me up!!!

    C'mon guys, it's a problem. Why do some do it and some don't if it was "designed that way" ??? So the ones that are quiet are defective???
  • tucsonjwttucsonjwt Posts: 283
    engine that came out with the 1997 model Corvette? If so, why aren't the Corvette owner's experiencing the engine knock? Or maybe they are and I don't know about it. Inquiring minds want to know. ;o)
This discussion has been closed.