Buick Rainier, Chevy TrailBlazer, GMC Envoy

scottc454

But... these things do have complex computer system controls that will in time readjust to the programmed parameters.

Says who? A few people on the internet? I'm not saying it's not possible. I'm just saying it takes way more than some anecdotal evidence from some random Joes on the internet to convince me that they can't make a chip that overrides some parameters.

Also, no where in that paragraph does it say anything about this being a "learning" computer. It says it monitors a bunch of sensors. It never says it saves these parameters. It talks of speed density algorithm. That sounds like it monitors airflow speed and density and decides how much fuel to add. I'd think the chip would just increase the amount of fuel to add, since the best power is made with a slightly rich mixture.

If someone wants to put up quarter mile times about this stuff, then I'll gladly listen, but to say that "it feels faster" isn't enough for me. I'm all too familiar with the folks who put loud exhausts on their Honda civics and think they've got a racecar.

gator36

What tblazed has talked about is also known as
BLOCK LEARN. The transmission shift adaptation has been around on GM models fro a few years. I saw it first had on my 97 sierra truck. The way to easily clear the block learn is to disconnect both battery cables and touch them together. This drains the capaitors that retain the settings.

lurker01

"Yes X3. Problems with water getting in the motor cover that also covers the internal pc board that controls the wiper functions. Go get a new wiper motor [non-permissible content removed]'y at the dealer. NHTSA was supposedly studying these and possibly a recall coming. "

Any idea where I could find a TSB or other info on this? I am out of warrenty and would like to present a convincing story to the dealer to get GM to pay for this.

Thanks!

tblazed

That's what WE are here, too! A few people on the internet, relating our experiences. That's why I researched these things and asked some people on other boards that have actually bought and used them. Decided from others experiences to leave the override modules alone and wait for a programmer.

And yes the PCM does monitor variables like the before and after cat converter O2 sensors for the correct fuel/air mix, etc, and stores the trim changes in some of that 1 meg of memory so it doesn't have to re-do those corrections every time you drive it.

tblazed

Here's the Bloomberg news story I have saved from last September. Can't find an actual bulletin on this. Maybe someone with better access can. But this will help document that wiper failure is a known, ongoing problem.

WEDNESDAY September 24, 2003

Windshield-wiper woe may force GM recall

General Motors Corp. faces a U.S. investigation that may result in the recall of 662,000 of its 2002 and 2003 GMC Envoy,Oldsmobile Bravada and Chevrolet TrailBlazer SUVs for a windshield-wiper problem.
 
The National Highway Traffic Safety Administration said Tuesday on its Web site that it has received 18 complaints that the wipers fail while driving, don't turn on when needed or can't be turned off. No crashes or injuries have been reported, the agency said.

scottc454

That's what WE are here, too! A few people on the internet, relating our experiences

Exactly. I don't expect everyone to agree with me or believe everything I say, that's why I prefer dealing with hard, concrete facts.
I still have a problem with people saying "the PCM learned around the chip" and stuff like that, because that sounds like it came from someone who doesn't know a thing about how software works.
I suppose we can agree to disagree for now.

tblazed

"I still have a problem with people saying "the PCM learned around the chip... sounds like it came from someone who doesn't know a thing about how software works."

Yes I agree, it does leave some doubts, but my conclusion after reading the description of operation in the service manual, and the reaction over time some people have reported, that IS probably how the software works. It corrects for sensor readings within a certain allowed range that don't match with the baseline programmed parameters like trans pressures, shift adapts and fuel trim and stores those changes. One thing it notes is when the system looses power long enough, the vehicle may not drive or behave like the customer expects until those adapts and trims are re-learned by driving. I suppose if you could trick the PCM to read the sensor signals are within normal range it would not re-learn around the add-on module.

Seems to me, the best effective way to alter the tuning is by changing the software. Personally I am not willing to spend a couple hundred bucks to find out if the people relating their experiences are right or wrong. I'll just wait.

email Hypertech!!

ross1962_99

We used to have them here in California, 30+ years ago - before I could drive. The used to have spot checks where they'd pull cars over and inspect them, sort of like the "sobriety checkpoints" they have now. What a hassle if you were running late!
They were replaced in the 70's by the smog check - back when California was the only state to do this.

tjcishere1

Just wanted to log on with an update i have an 02 Envoy XL SLT with 23,000 miles on it. Truck is running great just put the Exhaust tip on the truck looks great. Was wondering since everyone is talking performance has anyone used that product called the Tornado Air? i was wondering if it does help gas mileage. Just this past weekend did mostly all highway driving from Pa to Conn. on Rt 84 a few hills also i got 18.8 on Dic and when i filled up it was right on the money. i have a 3.73 rear and it was driving an average of 315 miles at 65 to 70 mph. any feed back would be great thanks in Advance

n7don

Tornado Air:
This article suggest it's second best to 'duct tape': http://www.kirotv.com/consumer/2220354/detail.html
Here's another link where the author tested fuel saving products over several months. http://autorepair.about.com/cs/productreviews/fr/aafpr052002.htm

scottc454

Thank you for posting this. I love it when people actually do quantitative tests on these gadgets. I wish I could think of some gimmick to make money on. Hmm, maybe aerodynamic paint.

tmarkb2

Thanks 01 hoe.

Mine is 2-wheel drive w/o the LL suspension. I had a friend/mechanic with lift, spring compressor, alignment guages, etc. help me with the Eibachs on a Saturday a.m. Not an average-joe weekend project. I got them from TireRack and once again, I can't recommend them strongly enough.

Thanks for the heads-up on a programmable rather than a chip. Something to check on further.

3.73 gears.

tblazed

Went through this debate with a friend that has a Tornado on a Toyota pickup. He "thinks" it helped, but not sure. Placebo effect?

My question would be on one of these 4.2s, if a Tornado is installed in the air duct, ahead of the air resonator [non-permissible content removed]'y, then the air enters the resonator on top of the engine, that would effectively straighten out the spinning around air. Then, even if the air was still spinning around as it enters the intake port, what happens when it enters the Vortec head design? Is the Tornado swirl clockwise and the Vortec putting a counter-clockwise spin (or vice-versa) on it, effectively cancelling out the spin? Hmmm...

The 6¢ resistors being sold as "chips" for $10-20 that claim to boost power 17 hp are another gimmick, being sold on that auction web site every one knows.. just a warning.

dwayne2004

Anbody know where the Bose amplifier is on the 2002+ Envoys??

quickdtoo

See message #9361. You'll get your answer sooner if you use the "search this discussion" feature as I did.

cparise1

Edmunds has a maintenance area with all the TSB's listed for your triplet. I've also read some excellent advice from people in the auto industry that your best approach is to win-over your service writer Vs. shoving a bunch of TSB's or newspaper articles about a potential problem with your vehicle down their throat. If the problem does not get fixed or diagnosed then you may have to change your tactics a bit by suggesting "well have you checked to see if this is a known problem" or something like that.
Hopefully, you've got a good dealership to work with. The few I've dealt with in south eastern Wisconsin have been excellent with diagnostic work.

Good luck,
Chris

ficuss

Why not take the car to the dealer, show him/her the problem and ask to have it fixed. They can't say it's normal, because it isn't. If they want your repeat business, they will fix the problem and if it is within the warranty period you won't pay anything.
 Just for the record, my TB wipers did the same thing. I brought the car to the dealer, explained the problem, they checked it and they replaced the wiper motor. End of story. There is no need to confront the dealer with a stack of TSB's. If you can get the TSB's, so can the dealer.

Frank

stever

Y'all have covered it nicely, but here's more:

You, Your Vehicle and the Technical Service Bulletin (TSB)

Steve, Host

cparise1

I was about to post the url.
Chris

trevor57

Good afternoon folks. Just got a dealer quote on SLT with leather, heated seats, side airbags, Bose, 6 CD sound sysytem, sunroof, running boards, really everything but NAV system....$33600 which includes destination. Only other $$ would be tax/tags. What do you folks think about this? Really want to believe in GMC again....also looking at 4Runner, but Envoy is much more comfortable!

01_hoe

I looked at the '03 4Runner before buying my '03 Envoy SLT. Agree the Envoy felt much more comfortable. Very satisfied with my Envoy. Price sounds very competitive, like dealer wants to sell you a vehicle. Good luck.

aldan93

Well my TB in this cold snap 0-10f is making some very interesting noises on start-up, sounds coming from under the hood, very hard to explain the noise, but it is on start-up!!!!and annoying, it goes away after 3 seconds. Wondering if anyone else experienced this lately?

mgriff27

I don't believe it. I had to have my TB LS towed to the dealer today because the truck would not drive faster than idle. Would you believe that rats have chewed through all the wiring in the engine compartment??? What the !!??

Unbelieveable! Like I have an extra $200 laying around to replace wires! Freaking rodents!!!

tblazed

"Havoc" or "Just One Bite" works quite well on rats. You are lucky if all they did was $200 in damage.

ken148

I bought my 2003 Envoy Dec 2002 & keep it outside. On first startup on a day when it is below zero the steering pump makes a god-awful squawk noise lasting from a few seconds when near zero to 10 minutes or more when 5 or 10 below! There is a TSB for the 2002 Envoy recommending a drain & flush of steering fluid but my Dealer says that according to the GM Techline this does not help the 2003. Has anyone else had this problem?

scottc454

That same squawk has happened to every vehicle I've ever owned when it's that cold, but only for a few seconds.

As for the rats, it's probably time to stop parking the truck in the dungeon!

bobbies

I noticed some comments on stone chips at the front of rear door. I have a black 02 and the chips start immediately. I found the best fix is to have it repainted and get 3M clear vinyl protector. 6" wide roll is about $40 dollars at a good parts store. Got to paint chips first cause the tape is clear and chips will show. Every spring (I'm in Ohio) I will remove, if it shows sign of wear and put on a new piece. The spot is pretty small so not much tape is needed. Can hardly tell it is on and paint stays fine. Works great!

tblazed

This is the Ground Force 1085 rear spring kit. Exactly what I was looking for! A set of rear springs that would level the stance of the truck, plus it handles a little better and even rides better likely from the variable rate to the springs (4 top turns close, 4 bottom turns farther apart) Excellent! And, maintains decent ground clearance. 2 hours install time in the driveway.

 

01_hoe

Looks great! All TB's should look level like that.

BTW, did you color match your "D" pillars? And is that a Borla system?

Very nice ride!

ylab

Hey Tblazed,

Do those springs come with any front end parts to compensate for the change in castor (and probably camber) which is going to result from lower only the rear? By lowering only the rear, you've just shifted the castor axis on the front end by at least a couple of degrees, which will most likely also rotate the camber slightly out of alignment. - I'm thinking tire wear may be affected, but only time will tell.

Ray

tblazed

No haven't done anything else except remove the "LS" badges on the side door pillars and the two rear liftgate emblems. Didn't notice it before but looks like the sun was reflecting just right to make the rear (D?) pillar look like it got painted. (I think that's what you meant.) Might have to be the next mod! I like that reflection. Also added a brushed stainless steel Chevy "bowtie" trailer hitch cover so it won't loose it's identity completely from the rear.

Affirmative on the Borla.

cparise1

Love the understated treatment you gave your TB. You rock.
Chris.

tblazed

Yes I thought about that. Caster angle mostly would change a little. Don't think it will have that much effect on tire wear. Like you said time will tell, and I do watch the tires. At 7500 mi the fronts were showing a little outer edge feathering with everything stock. So I reduced the toe-in a little and rotated front-to-back. Now, driving it with the new springs, no noticeable difference in the steering force, or any change in back-to-center force when I let go of the wheel that the caster angle has an effect on.

There's some tolerance in the alignment specs anyway- Camber -1 to 0°, -.5° preferred, caster 3 to 4°, 3.75° preferred, and toe-in spec is -.1 to +.3°, .1° preferred.

previousamigo

Can anyone tell me if the radios (without the band button) from the '02 TB's have the same pin connection and wiring in back as an '04 radio with the "band" button? I'm just looking to get another factory radio with the band button to hook up XM satellite radio. The dealer said they would reprogram the radio but the parts department couldn't tell me if the connection was the same in the back. I know I still need the XM Direct reciever (if it ever comes out) and wiring attachment.

Has anyone put 255/65R17 tires on the TB LTZ wheels? According to my calculations this would bring the tire to 30 inches vs. the 29 1/2 inches for the original 245/65R17's. Is the extra half inch in diameter going to cause any speedo problems and will there be any rubbing? I did notice the Rainier 17's have 255/60R17 tires which puts them at 29 inches.

tblazed

a little cut-and-paste... reload the pic...

pepper50

Y'all have covered it nicely, but here's more:
You, Your Vehicle and the Technical Service Bulletin (TSB
Steve, Host

Steve, why does that page appear in the "TIRES" section? Is it misfiled? I would think it would appear in an article section on its own; I would have never looked under Tires.

tidester

That's odd. You, Your Vehicle and the Technical Service Bulletin (TSB) leads to the same article but it's under Maintenance!

tidester, host

pepper50

In changing the air filter of a 2002 Envoy, do you have to take off that metal crossbar first to remove the air filter housing top? Or is there a way to slide the housing top out from under the bar? If I remember correctly, the photo in the manual doesn't even show that bar being there. Any of you who have changed your filter, did you have to remove the bar? Thanks for info/tips.

ficuss

Tblazed, IMHO, your TB now looks a lot like the Subaru Forester. Lowering the rearend has taken away the one unique feature of the TB. Removing the roof racks also de-identifies the car as a true TB. Don't get me wrong, I don't like unnecessary embellishments and cladding as much as the next guy, but again IMHO your TB now looks like a small SUV. It has lost its aggressive stance.

Frank

tblazed

So much for Ficuss approval. All the more reason to like it IMO. SO far I am running about 99% "for". And I like it. Handles better, ride quality is improved, easier to get in and out. Looks even more aggressive to me.

previousamigo

Tblazed,
Nice clean look. Did you put in a stiffer and bigger sway bar in the back end and new bushings up front for body roll? Do you have any pictures of what you used to plug the holes when you took off the roof rack. I also took off the rack but just put back in the same screws with a lot of silicone to keep water out. I would like to have something with a lower profile instead of those black factory screw heads sticking out on the pewter roof.

scottc454

Sorry, but I have to agree with ficuss.
You've "soccer mom'd" out that there Trailblazer.
You may not care about Ficuss approval, but I expect you'll be losing sleep now that I've disapproved. :^)

tblazed

the new upcoming Trailblazer SS. Lowered, de-emblemed, no roof rack...

quickdtoo

For another old guy's opinion, I like it! If I were able to maintain or improve the ground clearance, I'd do it too, but I'm going for the same look with a little more clearance up front by raising the front with a pair of coil spacers. I like the level look, not the back-end-up-in-the-air look. Nice mod, Ed. Tim

tblazed

I used plastic screw caps that fit the "heads" of the inserts in the roof. Available at Home Depot, Ace hardware stores etc. They were already white so I didn't have to paint them. Sanded them down on the bottoms about 1mm with 180 grit so they wouldn't sick up as far, glued on with RTV. Can be removed and the roof rack reinstalled in about 15 min. Sure makes it a LOT easier to wash and dry off the roof!

As far as other suspension mods, I put on the Hotchkis rear bar with the front and rear urethane bushings a few months ago.

ficuss

are not words I usually ascribe to a feeling about a car. Ed, I didn't say I hate yours or love mine (TB) that is. My COMMENT was only that, a comment, that your USUV (unidentified SUV) now looks like a Subaru Forester from the side. If lowering the car 1/2 " at the drivers door area makes it easier to get in and out of, that's great. It still looks like a Forester. I like the looks of a Vette. If I bought one, I doubt I would raise it several inches to make it easier to get into. As far as handling goes, did the upward slope of the rear of the car provide downward force to keep the car closer to the road at higher speeds?
 I guess I just don't understand why someone would buy a car, defend it against any criticism and then change everything about the car and remove its identity.

Frank

ross1962_99

"Looks great! All TB's should look level like that."

No they shouldn't; they're trucks.

previousamigo

Thanks for all the information and lively entertainment!

ficuss

previousamigo, don't just sit there, jump in

Frank

previousamigo

The only reason I took off the roof rack is because I've never used them since owning 3 SUV's ('84 Ford Bronco, '92 Isuzu Amigo, '02 TB) and the whistling noise from them was driving me nuts. I did keep them just in case I learn to snow board in CO this winter...

I'm the furthest from being a gear head. I think this forum is great but only like to dip my toe in when I have a question or problem. I do have many of the same problems that everyone else posts here. Currently, I'm ready to take the LS back to the dealer (still under warranty) for the 4WD switch that locks into 4HI when in A4WD on dry pavement (mixed with patches of snow) and won't come out of 4HI (yes, I understand not to use 4WD on dry pavement). I understand when it is supposed to go into 4HI (detects slippage) but what is the criteria for coming out of 4HI when in A4WD? This will be my 3rd 4WD switch...

That should be enough fence sitting!

But wait! Has anyone out there successfully hooked up XM or Sirus satellite radio through the AUX in the back of the factory radio?