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Chevrolet TrailBlazer Maintenance and Repair



  • burdawgburdawg Posts: 1,524
    Sounds like the viscous fan clutch to me. It's been discussed quite often in the triplett forums, but mostly in the earlier days. Look at the tach when it happens and you will probably see that the rpm's are close to normal. It sounds loud since the fan is spinning faster than normal, and vortex engines have loud fans (take a look at the cooling fan, it's a large diameter with highly pitched blades). Ours does it from time to time but it hasn't been something that I care to address, since it's only occasional and doesn't last very long.
    An improved clutch assembly that is better at low temps is available, but it's $$$$ if your out of warranty.
  • I don't have a TB but have a Silerado that had the exact same problem turned out to be a bad sending unit
  • burdawg, Is this condition hurting the engine? I just parked it. It was screaming all the way home. (15 minute drive) I am curious to know if this is something that was rectified in later production models. What exactly is the cure. We use the vehicle to travel all over the country.
  • burdawgburdawg Posts: 1,524
    If it's what I suspect and it's doing it all the time, then the only cure is to change the viscious fan clutch. You should have it looked at though to determine if that's really the problem. The transmission is shifting normally, right? It's not staying in a lower gear is it? That's a different problem all together.
    If it is the fan clutch, the only detrimental things I can think of by driving it that way is of course the noise, and reduced fuel mileage since the fan is running hard all the time (the purpose of the viscious clutch is to increase fuel mileage, which of course has been mandated by the federal government).
    As I said our 02 does it only occasionally and then it doesn't last long, but we live in a warm climate bouncing back and forth between So. California and Arizona. I do believe it happens more in colder climates.
    You should check with your local dealer and see if can be repaired under some type of hidden warranty, since they came out with an improved fan clutch due to the owners complaints. Also if you haven't done so search in this forum for others that have had the same issue. They may have more knowledge of it than me.
  • Thanks, The transmission seems to be shifting all right. I will check with the dealer. Hopefully it's not something too expensive. My mechanic told me that TB's are equipped with thermal fan clutches. I assume that is what the viscious fan clutch is. Again thanks for the help! :)
  • gdog2gdog2 Posts: 2
    Hello everyone! I'm new to the Trailblazer arena. I just purchased an '06 TB EXT. Love it so far, but I am curious as to why the instrument/dome knob does not light up along with other knobs/buttons when exterior lights come on. I had the dealer look into this and they came up with that there is no bulb behind the knob. I don't know if I buy that or not. Does anyone elses light up?
  • wxman4wxman4 Posts: 53
    '03 and no light either. Hmmm..., one knob you may actually use in the dark and it is not illuminated. Anyway, I think your dealer was correct.

    FWIW, we just purchased an '05 Malibu. On it neither the electric mirror select switch nor the window switches on the rear doors illuminate. Little light bulbs must be expensive.

  • gdog2gdog2 Posts: 2
    Yeah, I can't believe they didn't light this button. The badging must be getting expensive as well. The only place it says "TrailBlazer" is on the rear lift gate. Oh well, thanks for the reply. :)
  • i have a 02 chevy trailblazer with 70k miles and the tranny blew . i was driving to a friends house and i lost my drive gear went out so i went down to 1st gear and i would have to shift through gears and now i only have reverse . gm knows that the 4l60-e transmission has problems and they need to do something about it !
  • gmfangmfan Posts: 188
    The sad thing is that the owner's manual says the tranny fluid does not have to be serviced until 100K miles on the 02-04 models. I was talking to a Chevy mechanic the other and he said starting on 2005 models, GM changed to owners's manual to a more frequent service interval for the tranny fluid. That is ridiculous...Can someone out there with a 2005 confirm the manual has been changed? \\ :confuse:
  • Tonight went to start the 2002 trailblazer. Would not start... all lights came on radio came on... however thought it was a low battery. My husband came to the rescue. Not the battery. He thinks although the shifter is in park, the trailblazer is not. The steering wheel will not lock as it does in park, and it locks the keys in the ignition as it does until you get the car into park. He thought maybe there was a safety switch on the shifter. Shifter will not disengage at all. Anyone else have this problem???
  • gmfangmfan Posts: 188
    I have seen several posts in the past on this issue. There is a way to get into the shifter console and release a lever that will free it up so they vehicle will reset. I recall even seeing someone posts some pictures which will help you.
  • So about a week ago I was left work and noticed that the Air Bag light on my instrument panel was on. Not exactly sure why that happened, I shut it off and restarted. The light was no longer on. Ok, fine. The next morning, after starting it the light was back on, but this time I also noticed that the seat belt light was on when I had already fastened my seat belt. Tried to shut it off and restart it, but this time that didn't do anything.

    I've since noticed that when I turn my ignition to run, there is no chime reminding me to put my seat belt on (like I know it used to do), the seat belt light stays on like it would if I didn't have my seat belt on (its shuts off after about a minute like it would if I wasn't wearing it), and the air bag remains on.

    This morning, the problem happened again after sitting for the weekend, the lights came on, I shut it off and restarted it and they all went off. I know there's been electrical problems before, but has anyone had anything like this. I know exactly what will happen when I bring it to the dealer, they'll scratch their heads and start replacing things and probably not know what the problem fully is. '02 Trailblazer LS with about 70,000 miles.
  • imjimj Posts: 2
    I have owned a 2002 Trailblazer for one year now and I have had continuous problems with my headlights on low beam. I have replaced both headlights at least twice. My husband figured out that we weren't burning out headlights but the connection plug was getting too hot. He has now replaced the connection twice on both the passenger and driver side. It seems that both lights work for a couple of days and then I lose one. I don't have a problem after one of the low beam lights goes out and my high beams work fine. Of course this causes the day running lights to not work properly also. Something is causing those connections to get hot but my husband has not been able to figure out what. Has anyone else had problems with keeping the headlights working on their Trailblazer?
  • We had this problem last fall with our 2002 Trailblazer. The first time it happened, I tried replacing the battery. Shortly afterward it happened again, and we took it to the dealer. It took them about 4-5 days to isolate the problem. There are a number of body control computers in the Trailblazer. After you leave the vehicle, it can take up to 1/2 hour for all of them to power down and go to sleep. On ours, the computer located in the tailgate would sometimes not power down properly, and would then drain the battery. The reason it took the dealer so long to find the problem was that you have to turn the electrical system on, then turn it off, wait 1/2 hour for everything to power down, and then look for abnormal power drains. Since it was an intermittant problem, this had to be done over and over until the problem appeared and the component at fault identified. In the end, Chevrolet covered the replacement under warranty, even though the mileage at the time was about 50k.
  • 2002 Trailblazer, occasionally when turning there is a noise that sounds like the left front tire is rubbing on the fender, sort of like a grinding noise that last for 1 second or less. When it happens it is quite loud, and you can feel the vibration either through the body or the steering wheel (not sure which). Has anyone else had this problem? It is definitely mechanical; CV joints? Power steering pump?
  • burdawgburdawg Posts: 1,524
    In 37K miles I have replaced the left lowbeam twice. The last time the connector had been hot and the contacts were discolored as you describe. I cleaned them as best I could, put in a new halogen bulb and so far it's been OK. I suspect it's a reaction between the metals used which causes some corrosion on the contacts, which causes a resistance to build up, which causes heat that compounds the problem - I think you can see where I'm going. I used an aftermarket brand of bulbs, which may be part of the problem. I'm going to check on it now that you have reminded me and see if it's recurring.
  • well i too have a 02 tb, and just within the past months i have replaced the connectors on both sides, and i have the same problem, the connection gets too hot and burns the plastic, i am looking for a solution to the problem but cant find anything, so if you or anybody else has the same problem and found a solution to fix the problem please let me know, im tired of replacing headlights and connectors.
    thanks mark
  • I have recently started to experience a problem with my 2005 TB EXT and the AWD transmission. I was driving at ~60mph in the 2HI setting and all of a sudden the light came on the selector switch that it was switching to A4 AWD, then both lights were lit at the same time. I could feel the transaxle switching between modes and thought it was going to shut the engine down or stall it at least. It always seemed to correspond to letting my foot off of the accelerator to coast whilemaintaining speed. Has anyone heard or experienced the same problem? :confuse: ">
  • I have a '02 TB LS and this happens to me about once every 6 months where the lights on the knob will switch the system to 4X4 without touching it. Dealership has replaced the turn knob at least 3 times and done multiple "reprogrammings". It happens infrequently without any ill effects so I gave up trying to fix it. Do a search on the other TB forum and you will see many posts on this problem. Seems that GM still does not have a fix yet. Just make sure you manually turn the knob a few times to get it back to 2HI.
  • gmfangmfan Posts: 188
    My 02 TB is simila. It no longer chimes nor does the seatbelt light luminate when the vehicle is cranked. Not that I really need the reminder, so it is no big deal. My light with the seat belt and air bag does flash for a few seconds, but again no sound (by the way, what is that icon?) Mine has 80,000 mi and has been doing this for at least six months. Seat belt with air bag icon is weird, since if the air bag is acting up, the "Air Bag" light will illuminate right?

    Nothing is broke, but since I read your post,
  • :lemon: the trim piece housing the 3rd brake light can deatch from its plastic hinge mounts causing the lift gate to become inoperable.

    See my complete posting and ordeal with General Motors at under posting by damiantote.
  • I had that noise too on my '02. It was a while ago but I think there was a recall on it. Something about a computer chip. Check the dealer for recalls on the noise. Also didn't want to shift when that happened.
  • bdeekbdeek Posts: 2
    Would you be able to tell me how to change the lightbulbs on a 2002 Trailblazer?

  • bdeekbdeek Posts: 2
    Can someone tell me how to replace the light bulb for the headlamp on a 2002 Trailblazer?

  • I keep hearing a clunking coming from the front left side of the vehicle. I thought it was just some of the plastics from underneath. I was told during my last oil change they said it was the sawy bar bushings. The TB has about 86,000 miles on it. Should these have gone bad. Would anyone know if they are difficult to replace, or where I could find an online manual to do it? Thanks
  • From what I can remember, without tearing the front end off the car, if you look under the hood to the back side of the lights you will see wires leading to the back of the headlight. These will usually screw out with a strong hand, and small arms!! replace the bulb and you should be good to go.
  • First, my SES light comes on periodically. If I re-adjust my gas cap it goes off. I think it has something to do with the pressure inside the tank. Anyway, that problem solved on to the next. I have a 2003 TB. I have just recently started having a problem that when I come out of the mornings (especially when it is cold) my car is reluctant to start. And, my clock resets to 12:00 everytime (which would indicate a loss of power). This was just happening in the morning but now it seems it is happening almost everytime I get in the car. Also, my reduced power light does come on when I start the car but it goes off once the car is running. I thought it might be a low battery but am not sure. Any thoughts?
  • gmoudygmoudy Posts: 67
    Yep! Sounds like your battery is going. The cold just made it appear quicker.
  • Does sound like the battery, those Delco batterys don't last very long. The one in my 03 TB didn't quite make it to 3 yrs. Which is better than the one in my 99 Blazer which only made it a year and half.
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