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Buick Rainier, Chevy TrailBlazer, GMC Envoy

1310311313315316586

Comments

  • cmack4cmack4 Posts: 302
    Unfortunately GM decided to do away with the proactive system (torque is constantly split even when no slippage is detected) for the Bravada, so it's not a true full-time AWD setup like it used to be. However, although the old system was proactive, the viscous clutch was a lot slower to react to changing conditions then the electrically engaged wet clutch system. In many ways the new Smartrak is similar to A4WD, but the good news is that without the low range gearing, they are able to get extra wet pack clutch plates in the transfer case, which offer a wider variance of torque split conditions over the A4WD in the TB and Envoy and make it adjust better in on-road conditions. In my Bravada, I've noticed very little "jerking" when AWD engages, and it engages fast enough that I'm not able to break the rear end loose under heavy acceleration... even on slippery surfaces! The only time I've ever noticed any jerking is when my rear locker kicks in, but that only happens under 20mph.
  • funitsfunits Posts: 55
    Now that New Hampshire is 0°F, my Envoy has developed a strange "tea-kettle-like whistling" from under the hood. It generally starts whistling after 10-15 minutes of driving 50-60 mph, but stops when I stop the vehicle. Sometimes the whistle will start again when the vehicle moves forward, sometimes not. I am looking forward to reproducing this problem for service. Concerning jumpy brakes -- my Envoy, this past summer, would "surge" while stopped, as if I stepped on the gas while stepping on the brake, to cause the vehicle to "jump". Very annoying, but it went away . . . New problem, my driver's side window Auto-Down feature won't work -- window will go down (slowly) holding the window switch, but not automatically as before. I have enjoyed my Envoy and still like it, but I am waiting for the Volkswagen Touareg to hit the U.S. shores . . .
  • gam2gam2 Posts: 306
    The cold start whining you hear is the power steering pump. There is a TSB out there to change to a different fluid that doesn't scream at low temps. I suspect many dealers are getiing calls. BTW, my Subaru was even worse in cold weather.

    Sorry, but the Touareg is a PIG! Car and Drivers weighed way over 5000 lbs, yet was much smaller than a Triplet. Fuel ecomony sucked also. I'd wait a year also, as VW's are not real reliable in their first years.

    GAM
  • tlaurotlauro Posts: 504
    The newer Bravada may have more clutch plates, but the split is still a simple on/off transfer of a torque.

    The reason I prefer the older system with the viscous system is that it operated under a 35/65 front to rear torque split. A much more effective ratio while encountering wheelspin while rounding a curve. It could also transfer up to 90% of the torque to the front if needed. Overall, it's still one of the best systems out there. Hands down still beats the newer system. Much smoother and continuously variable.

    When driving normally, the difference in RPM of the two axles is minimal. If the speed of one set of wheels were to be more than the other, then the difference in speeds of the corresponding disc's in the Viscous Coupling will also increase. In this case the 51 inner discs begin to spin faster than the rest as these are connected to the opposite wheels. This would cause a "cutting" action within the silicone fluid as it is sliced between the slits of the interior discs and the holes of the exterior discs resulting in the silicone fluid heating up instantly. As the temperature increases so does the viscosity or thickness of the fluid. This causes the clutch plates to become increasingly locked together allowing more of the power to be transferred to the opposite axle via the external discs. My guess is the speed of engagement is less noticable due to the method and system. This system is still used by many other manufacturers on their AWD systems. Volvo, 911 S-4's and even GM's own Typhoon and Cyclone used this system too. This transfer of torque all takes place in milliseconds.

    The best part of 1996 was the introduction launch of the new redesigned Bravada in that day. Had more ride and drive comparisons that year on all types of set ups in the Detroit Proving grounds just because it was so fun to run in. Actually flipped a 4x4 Explorer that year in a run :)
  • dse1dse1 Posts: 22
    Sounds like a few of you have the front axle seal problem. Symptoms: in cool weather, before car is warmed, squeel/whistle (sounds like air escaping from a thermos of coffee) for the first 15 min or so of driving. If you want to 'demonstrate' for a dealer, you'll probably have to let the car sit overnight at the dealership, and you'll need cold weather. Solution: replace the front axle seals - I think there's a TSB, and there are DEFINITELY posts earlier on about this. If anyone has had this occur again AFTER the fix, let me know, only driven to the mountains twice this winter and no whine yet...
  • mookie14mookie14 Posts: 252
    i took my 03 tblazer into bp for a series of car washes over a period of time this winter. it was to cold to wash it by hand. well i found out today i have scratches on both sides of hood. i know the car wash did it no doubt. now the real deal how to get them out? without going to the body shop. there like this light not big some surface some i can see the paint but light so any help with this??????????
  • aldan93aldan93 Posts: 202
    Well I have 1125 miles on her and she has been back to the shop 2X's, Both for vibration starting around 40 mph thru-65 and a very annoying vibration/ humming at 60mph, Today they replaced the springs, I think it actually got worse!!!! I was wondering if anyone has had a similar experience? You only feel the vibration/ or it only resinates when you have your foot on the gas!!! I'm extremely saddened by the initial quality, other wise its an awesome ride! TB LS 4x4 275 hp pewter!
  • mookie14mookie14 Posts: 252
    i have a 03 ls tblaz and i heard it in the a little when they put the springs on. since i have not heard it since. really i think its something just gm needs to look at other than that. thats it
  • mookie14mookie14 Posts: 252
    can anyone respond to 9802 appreciate alot. thanks.
  • redline65redline65 Posts: 693
    Well I have 1125 miles on her and she has been back to the shop 2X's, Both for vibration starting around 40 mph thru-65 and a very annoying vibration/ humming at 60mph, Today they replaced the springs, I think it actually got worse!!!! I was wondering if anyone has had a similar experience? You only feel the vibration/ or it only resinates when you have your foot on the gas!!! I'm extremely saddened by the initial quality, other wise its an awesome ride! TB LS 4x4 275 hp pewter!

    I hate to ask, but did the dealer try the obvious like rebalancing the tires and checking the alignment? Whenever I've had vibrations at certain speeds on my other cars those are usually what I have done first.
  • redline65redline65 Posts: 693
    can anyone respond to 9802 appreciate alot. thanks.

    How deep are the scratches? If they are just in the clearcoat you might be able to use some car polish and buff them out. If they are down through the paint or primer you might need a professional touch-up.
  • I read this in the somewhere else on this board and wasn't sure what to make of it... My trailblazer has this engine knock when cold. Will GM actually replace my pistons to correct this? Has GM done this to anyone's triplet?

    "Look at this info:

    "2002 Trailblazer, Envoy, Bravada (GMT 360/370) S, T 2002 Equipped with the 4.2 L LL8 Engine Knock Noise During Intial Start-Up in Cold Ambients [10°C (50°F)] That Typically Quiets Down as the Engine Warms Up

    Some customers may comment about an engine knock noise that begins to occur within the first several thousand miles of use. This noise is most often noticed during initial start-up in cold ambients [10°C (50°F)] and typically quiets down as the engine warms up. This noise is more noticeable at 800-1100 RPM and/or 1700-2100 RPM. GM Powertrain engineering has determined that this cold engine knock noise is the result of an interaction between the engine piston and the cylinder wall. GM Powertrain engineering has also determined that this condition is not detrimental to the performance, reliability or durability of the engine. Realizing that this noise could be a customer satisfication concern, GM Powertrain has implemented a graphal coated piston for this application to address this noise. These new pistons have been in production since January 10, 2002 and will be available in service by June 1st, 2002. The part numbers for this piston is 88958991 for standard and 88958992 for 0.25 mm (0.0098 in) oversize.

    Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. This diagnostic approach was developed for the vehicle with the VIN you entered and should not be automatically be used for other vehicles with similar symptoms." "
  • steverstever Viva Las CrucesPosts: 41,948
    I'd also look around the Store Bought Waxes Part II (No Zaino Posts) discussion -- try an Advanced Search in there on "swirl." This thread looks good: pghtiburon - What do you think of this plan?.

    Steve, Host

    Moderator
    Minivan fan. Feel free to message or email me - stever@edmunds.com.

  • This issue with the piston slap, it appears, going to haunt triplet owners as well. Gm is struggling with this on many engines, the 3.1 being the most common. I have a 97 Lumina, noisey since new, now 180k and nothing has changed. My TB has a slight rattle cold for about 5 minutes in 10 degree weather, based on my experience with my car, I would hesitate to have the TB engine taken apart for this. Pistonslap.com has some very interesting info on this.
  • I had one of my low/driving bulbs burn out a while back. Meant to take it to the dealer but haven't gotten there. After washing it this afternoon (sunny and 67 where I am!), I decided it might be easier if I took the bulb out myself. There had been some discussion - I guess just for the TB - about how to gain access to the bulbs. On the Bravada it's a 30 second operation. There are two retaining clips with "handles" on them that pull up releasing the whole lamp assembly. Just pull it out from the front and the back is completely accessible.
  • While washing, it struck me that the Bravada has virtually zero brake dust on the wheels; much less than any other vehicle I have owned. My daughter's Focus wheels are dirty after the first trip. Are these pads a particular "low-dust" type or is it the design of the brakes/wheels? Anyone had theirs replaced yet?
  • I have had the vibration in my gas pedal since day one. I bought the car in September 2001. I now have 20000 miles and nothing has changed. I have taken it to the dealer multiple times and have gotten the "can't reproduce the problem" just about every time. I even got one tech to go for a ride with me and he heard it. Told me to bring it back the following week and he would explain the problem to the mechanic. Well, I did, and same old problem, couldn't reproduce problem - uughh.

    I got to the point where I just gave up. It also seems to be worse in the winter time.

    I just took my car to a new dealer to have some other things fixed, and he said that the rear coil springs were the problem. They had to order them. Should know in a week or two if that was it. I seriously doubt it. Anybody else have the vibration and get the problem solved?

    I also had the floor heat problem. When I took it in they fixed it using the new redesigned ducts. It definitely worked. I now feel heat on my feet! The only thing, I think the cabin area of the car now feels cooler - uugh!

    Additionally, I had the passenger mirror go and start to wander. The driver side I had fixed last year, now this one.
  • The clock in my 2002 TB LTZ needs to be frequently reset. Also the autoset feature using the "info" radio stations no longer works. Any ideas?

    I've also noticed that after 12 months of ownership, it seems the wandering mirror problem has hit my car.

    Can these be related?
  • aldan93aldan93 Posts: 202
    I have the same problem as 9813, guess what buddy I got the springs replaced, and I think it got worse! I had them replace the springs Friday 1/24/03. And for the balancing tire thing ha! ha!

    This vibration is in the Drive-Train! When you press the gas or have your foot on the pedal it vibrates 40-65mph, it almost gives you a pulsing sensation that kind of gives you head ache!!!
    But if you let go of the gas it stops. So drive, shaft? Yoke? Transmission? Torque Converter?, bad gear set? already replaced the springs! And there was a service bulletin on that?
  • ross1962ross1962 Posts: 229
    I have noticed a loud, thundering noise at about 300 mph. This quiets down abit about 310-320.
  • phkckphkck Posts: 185
    I think there is a TSB that will fix that. Although, that is a pretty slow idle!!
  • redline65redline65 Posts: 693
    I have noticed a loud, thundering noise at about 300 mph. This quiets down abit about 310-320.

    What kind of plane do you fly?
  • We received our first real snow in Des Moines, Ia last Saturday. I also noticed last Friday that the 4wd selector switch light stopped working on my 2002 Chevy Trailblazer LTZ. I didn’t think too much about it until I turned it to 4hi and found out all I had was 2wd. You can image the thoughts going through my head as I fishtailed all the way home in the new snow. I have seen a few posts indicating some other trailblazer owners have experienced a faulty 4wd switch, which caused the 4wd from engaging. Chevy, what the #$@! is wrong with you? Why can’t you make something dependable enough to drive in adverse conditions? Do you think that installing a sub-par switch and saving twenty five cents is going to make people feel confident driving a GM product? I am glad I wasn’t in an emergency situation or out the middle of an off-road trail that required 4wd to get home. Based on my experience and the other experiences I have read on the web, I can’t see owning this vehicle beyond the 3 year warranty. If I could sell this vehicle without taking such a hit in my pocket book, I would.

    Now for the good news! As soon as I got home, I jumped in my wife’s 2002 Jeep Liberty, pulled the 4wd lever and went for a ride. The 4wd worked flawlessly as it tracked through the snow with ease. My wife sat quietly next to me with a big smile on her face. I am thinking my next vehicle will be a Jeep Grand Cherokee.

    By the way Chevrolet, I am also going to post this on the jeep forum as well. It is time for you to start taking ownership of these problems and get them fixed. If you knew about a faulty switch, why wasn’t there a recall? This is a safety issue.
  • 2002slt2002slt Posts: 228
    From post 9819:
    "I also noticed last Friday that the 4wd selector switch light stopped working on my 2002 Chevy Trailblazer LTZ. I didn't think too much about it"

    You didn't think too much about it? Why not? That would raise a red flag with me. If the light went out I would assume no power was getting to it, and taken it in immediately. Hmmm...

    BTW - I believe there is a TSB for your problem. It's not actually a "safety" issue. 4WD is a convenience option, unlike brakes, or steering. Good luck with your Jeep. They're not perfect either.
  • aldan93aldan93 Posts: 202
    Please respond if you have this problem, or if you know what the fix is please! Its only when you press the gas! If you let go of the gas its fine, My springs have already been replaced!
  • "You didn't think too much about it? Why not? That would raise a red flag with me. If the light went out I would assume no power was getting to it, and taken it in immediately. Hmmm..."

    I thought it was just a burnt out bulb. I was going to take it in to have it checked out next week.
  • ficussficuss Posts: 541
    The issue of vibrations has been around here for a while. Earlier posts mentioned vibrations described as low level rumbles around 55 mph. Feeling it through the gas pedal is misleading. There is no mechanical connection between the gas pedal and the engine, or drive-train. The pedal is mounted to the vehicle chassis but not connected to the engine. When you let up on the gas, all parts which were moving and spinning are still moving and spinning, but at a slightly slower rate. Then your foot is not touching the gas pedal so you don't feel it. I think that if you pay close attention to the precise speed at which you feel the vibration, you will be able to predict exactly when the vibration will happen. Is this what some of you are experiencing. If so, this may be due to natural resonance of moving parts. Some cars have a speed at which the whole car will seem to resonate, or vibrate. Replacing your springs probably won't stop a vibration. Shock absorbers are supposed to prevent suspension vibration by dampening the movement. My TB LTZ used to resonate at about 55 mph. Since my engine was replaced due to a cylinder failure, my TB no longer resonates at that speed or any speed for that matter. Looking back, could my engine have been just slightly out of balance? Was the front bumper cover or grill cover loose before and tighter now? Anything which is loose will vibrate at some speed. Finding the loose part may require a wind tunnel for a loose body part or a dyno test for a drivetrain part. I doubt that GM will pay for either.

    Frank
  • nuyorkahnuyorkah Posts: 100
    "I also noticed last Friday that the 4wd selector switch light stopped working on my 2002 Chevy Trailblazer LTZ. I didn't think too much about it"

    This may get 4x4 back temporarily if your really stuck.

    Try taking out the fuse marked "ATC" in the
    fuse block in the engine compartment while the engine is off, wait a few minutes then put it back in. See if light comes back on. If this does work you still have to make a service appointment and have some reprogramming done as this is only a temporary fix.
  • 4WD is a convenience option, unlike brakes, or steering.

    For people that live in the snowbelt or the mountains, 4wd is often a whole lot more than a convenience option. Unless of course you think that parking on the side of the road to wait for the plow/sand truck is a valuable use of your time.
  • pluto5pluto5 Posts: 618
    GM usually gets it right but it takes 2-3 yrs with a new model which the TB surely is.
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