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Buick Rainier, Chevy TrailBlazer, GMC Envoy



  • I have exactly the same problem , and they wont fix it. I personally believe it has too small of radiator for the engine size
  • Have your front stabilizer bar link bushings checked. THey are a common cause of the front end rattle over bumps. Mine were replaced and it drove like new again.
  • Because of emissions, modern engines are designed to run a lot hotter than they used to ... and probably hotter than is good for them, long term. Nevertheless, 210 is perfectly normal and isn't going to hurt a thing. 235 is getting up there, but still nothing to be too concerned about ... depending on operating factors (Texas heat, pulling a trailer, etc.). I doubt very much that the radiator is too small for your engine. You didn't say how many miles you had on the truck, but I would try a radiator flush ... and make sure they bleed all the air out of it. Might also try going to a colder thermostat if you are that concerned about the heat.
  • As hardhawk pointed out, it could be the front end. Bushings wear out on these pretty rapidly. But another thing that happens and sounds like it's coming from the front end is really the two adjustable stops under the hood. Raise them a bit, so they just make contact with the hood when closed. Then put a little silicone spray on them and se eif that makes the noise go away. (way cheaper than a bushing replacement)
  • My wife's 02 Bravada has the typical light "clunking" in the front end over rough roads. I've grabbed the front sway bar and checked for any discernible play in its end links and found none. So I'm thinking that it is the common problem associated with the intermediate steering shaft lubrication and wear that I've read about. The clunking can also be felt pretty readily through the steering wheel, which gives me more reason to believe it is in the shaft, and not the front suspension.

    Does anyone have access to the full text of the TSB dealing with the intermediate steering shaft? Alldata requires that you subscribe to their service, and I don't.

    I know there are at least two of these steering-shaft bulletins - one dealing with the full-size trucks and another specifically dealing with Trailblazers/Envoys, etc. That is the one I am interested in.

  • ylabylab Posts: 46
    mrgem, it takes very little play to cause the clunking and the clunking starts well before the sway bar feels loose. On my '02 Envoy the clunking started with only 11,000-12,000 miles on it and increased rapidly. I was sure my front end had something wrong with it, however after having the dealer replace the end-links under warranty it again drove like new!

    My advise would be to replace the end-links (they're not real expensive) and I'd be willing to bet the noise and vibration goes away. Cheapest place to buy those little buggers is, keep in mind that the left & right side are different numbers. (You can find the numbers by searching this forum ... they were given in April or early May of this year).
  • The October issue of Trailer Life has an article on two items to install on the 6.2L I-6 engine to increase performance. Their dynamometer tests indicated that with both items there was an increase of about 20 rear-wheel HP. Road testing showed a slight increase in fuel economy of about 1 mpg. Both items are from Airaid Performance Filter Co. One is an improved air intake filter and connecting tube. This intake helps in two ways. Less resistance to air flow and is arranged to take in cooler air. The second item is a throttle body spacer that further atomizes the fuel/air mixture. The Airaid Web site says it is 50 state legal, will not void new car warranty, and can be used with any grade fuel. Has anyone tried either or both of these? If so, with what results?
  • steverstever Posts: 52,683
    You can increase your mpg by up to 2% just by unloading 100 pounds of junk sitting in your car. (

    Check out Gas Saving Gizmos & Gadgets for more comments about spacers, etc. And you may enjoy the Breathe Easy: Int. & Exh. Headers + Mufflers and Pipes discussion.

    Steve, Host
  • I guess I did not make myself clear. The very slight possible improvement in gas mileage was not my point. I probably wouldn't bother with this modification to get such a small increase in gas mileage, although 1 mpg more is an increase of at least 4 to 5%. That was mentioned only to show that there seemed to be no degradation in mileage with these simple modifications. The point is to get a bit more power for pulling a small trailer without getting into more difficult things like headers and exhaust systems. The modifications and their evaluation seemed to be done by reputable people.
  • steverstever Posts: 52,683
    I'm a bit dubious since the intake has to go out somewhere; usually that means bigger pipes in and out, or so I've read over in that Breathing discussion I linked. Throttle body spacers don't make much sense to me either; if they worked (either for more hp or mpg), why wouldn't the manufacturer design them in to begin with?

    Come to think of it, I've read enough about hyped dyno reading to be a bit suspicious of them too. :-) . But I didn't read any more about this than what you posted either.

    While I doubt that most people could sense an additional 10 hp, twenty may be noticeable.

    If you go this route, it'd be nice to see a reliable baseline so you'd know that the benefit is more than a seat of pants feel.

    Steve, Host
  • I have an 02 TB I6, but used to have a Jeep Grand Cherokee (Chrysler 318 or 5.2L), and used a throttle body expander on the Jeep. Easy 5MPG increase. Cost about $40. Haven't done anything to the Chevy yet though...

    - WPK
  • ylabylab Posts: 46
    The bulk of any increase, and i very much doubt it was 20 rwhp, came from the low restriction filter and smooth intake tube. I have a system similar to the Airaid and it does help, especially above 3500 rpm....but the spacer didn't seem to do a whole lot.

    I had one on my Envoy and the whistle under light throttle was more annoying than any benefit. (Bet they didn't mention the blasted whistle!) With my Borla split-cat-back exhaust and intake, there IS a .5 to 1 mpg increase if you take it easy.....when the spacer was on, I think the economy actually went down a bit! Think about it, the injectors are at the intake valves and there isn't any mixture to mix or atomize at the throttle body.....just plain air, and it has to split 6 ways for each cylinder.
  • I think ylab has hit it pretty well on the head. The magazine article does show that the bulk of the improvement comes from the low restriction filter and smooth intake tube. And their results bear out ylab's experience about the help being most noticeable at higher rpms. They did mention the noise as "a slight increase in air-intake noise on the road, but only under heavy throttle". Very subjective. I was puzzled about the talk of a mixture at this point, but thought maybe I was missing something and that what was really meant was that whirling air caused more atomizing when the fuel was injected downstream. Thanks everyone for the comments. I think I'll just keep my money.
  • My 2002 Envoy with the I-6 pulls my 5000# boat/trailer with no problem. I did add the K&N filter when it was new and it does have the high pitched whistle at full throttle. What rear axle ratio do you have? I have the 4.10 and it is great for towing. The Envoy has been a great tow vehicle.
  • Is the '06 engine Hp increase do to engine improvements? or just due to just a re-spec'ing under the new HP rules? They're now calling it a 291hp engine, instead of 275.
  • have an 02 trailblazer with 245-70-16's. how large of a tire can i put on the stock rims. I'm thinking of 265-70-16 or 255-65-16 michelin cross terrain suv's I'm finding sketchy info
  • ylabylab Posts: 46
    For '06 they've increased the compression ratio a bit, made slight changes to the intake and tweaked the PCM. - Heck, they had to do something to tout their standard engine still has as much power as the optional V8 in the Explorer! :)

    So the changes are real and not just in the calculation of their numbers.
  • I have a 02 SLT Envoy. The upper brake light lens (the one above the lift gate) is peeling, it almost looks like a coating of varnish is peeling off of it. I bought the car new, and there has never been anything put on the lens. I wash the car myself and always use clean water. Has anyone else had this problem?
  • I have a 2002 TB, just noticed the same problem. Car has never been garaged, washed at commercial places. I wonder if this peeling is covered as a safety device defect?
  • burdawgburdawg Posts: 1,524
    Mine's the same. I use some plastic polish on it from time to time which helps. The UV plus the air (with the usual grit and grime mixed in) going over it in that exposure location are hard on it.
  • 01_hoe01_hoe Posts: 273
    Read on another forum of others with this problem. Dealers replace light and molding that surrounds the light. Do you have a warranty?
  • Thanks, Ylab. I will pursue that.

    Seems I'd read that the best replacements (non-factory) actually had grease fittings on them. IIRC, NAPA was one source cited. Do the RockAuto units have grease fittings?
  • Get MOOG brand. They are the best and yes, MOOG does sell greasable replacements.
  • mark77mark77 Posts: 4
    I need to change the headlight bulb on my envoy. This would be my first time to change a bulb on this car. Any suggestion is appreciated. Thanks.
  • ylabylab Posts: 46
    On the Envoy its a piece of cake......

    1) Ppull up on the two clips that hold the hadllamp assembly in and it gently pull forward.

    2) On the back are two round rubber covers which pull off like a coffee can lid, one for the low beam and another for the high.

    3) Remove the covers to access the bulbs to twist out and replace the bulb.

    Reverse steps 1 & 2 to re-assemble.

    If you want to ensure you don't scratch the top of the bumper, place a cotton towel between the headlamp and bumper before starting....or just be careful.

  • I am having problems with my turn signal relay- the relay continues to click after the turn signal is off. When pushing on the brake the noise goes away. The repair book doesn't cover this issue and their are no codes stored in the cars computer. Please help.
  • I'm still on original brake pads at 73,000 miles, I think that is pretty good.
    What kind of pad life is anyone else getting? Also brake dust is virtually non existant, and the brakes work great! GM gets an A+ in my book for this, :)
  • gam2gam2 Posts: 316
    Anyone pull rotors from a 4WD triplet to have them turned? Mine are bad at 36,000 mostly HWY miles. Probably turn the fronts first. GM gets a D- in my book. I've never turned rotors on anything with less than 100K miles before! My brake pedal
    still sqeaks and moans after 3 trips to the dealer.

  • burdawgburdawg Posts: 1,524
    At 36K mine are still very good. I expect to go past 70K easily.
  • ross1962ross1962 Posts: 229
    Totally agree on the brake quality. It's a big step up from the old S-10 Blazer. I'm about ready to replac mine at 55K, which is a very long brake pad life for my driving habits.
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