Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum banner
1 - 20 of 42 Posts

·
Registered
Joined
·
19 Posts
Discussion Starter · #1 ·
Hi guys! New here, and my first post/thread, hope someone can give me some light. Just bought an '06 Trailblazer as a beater, boy oh boy, is it a roller coaster! Brand new shocks in the rear, brand new rotors and brakes in the front (pulsating), brand new rotors in the rear (brakes still good). Left/Driver side CV axle bearing, new different fluid front and rear. Brand new thermostat (boy was I dumb, I thought the old o-ring was still good, so I tossed the new one along with the bad thermostat, now is leaking a tiny bit, so gonna buy one to put in).

Been fixing so many stuff and yet Check Engine Light after Check Engine Light...now, the last one, I hope, Code P0171, System Running Lean on Bank 1. Tried cleaning throttle, MAF, ordered an Air Solenoid Check Valve and it just arrived today (but waiting for the gasket), but here's where I'm really stuck. There is a hissing noise, can't really tell exactly where it's coming from, sounds more like the back of the engine left/driver side, but I think it may be in the intake also...upon shutting off, the engine rolls to a stop, then there's a click when this hissing noise stops. So, it doesn't seem to be a leak as it seems there's a switch that turns it on upon start and shuts it off after shut-off or something. But I could be completely wrong. It might be a bad leaking somewhere. FYI: I've tightened all the bolts (they were all loosed). Chasing the P0171 code by watching Youtube videos, a guy seems to have diagnosed his situation to be the Air Solenoid Check Valve, so that's the reason I ordered it as I'm running out of ideas.

I've spent close to $1K chasing after these codes the past two and a half weeks. First started with code for Canister Evap Valve Solenoid (fixed), then code for the thermostat not reach a certain temperature in a certain time (fixed), then this P0171, which makes my head spinning! I hope when I get the gasket and install the Air Solenoid Check Valve tomorrow, it fixed this last code. Then remember, the small leak because of my stupidity...that shouldn't be a problem, though. My main concern is the stupid chase-after the wind code P0171.

Any pointers for this hissing noise? I already checked the hose to the Power Booster Brake, it's not it. HELP!!!!
 

·
Premium Member
2004 chevy trailblazer_lt
Joined
·
3,001 Posts
Welcome to The Forum!

Check your exhaust manifold for cracks - a sort of common problem with TrailBlazers equipped with the 4.2 L engine.

Good Luck!
 

·
Premium Member
'05 Chevy TB EXT
Joined
·
5,138 Posts
Lean Bank 1 (the only bank you have) and a hissing sound is a vacuum leak ... or a very angry snake.

Your job is to find the source of the hissing by sticking some small diameter rubber hose in your ear and going on a treasure hint with the other end.

How much money did you spend already to get this free advice?

You guys (newbies) have gotta stop feeding the witch doctors trying to fix something by tossing virgins into the volcano.
Soon you'll be out of virgins and the volcano god will want YOU!​
 

·
Registered
Joined
·
19 Posts
Discussion Starter · #4 ·
Guys, thanks for the response! I was finally able to find where the hissing noise was coming from. And it makes me feel like a dumbass! It was my own wrongdoing! When I took off the hose that connects between the upper and lower manifold, I somehow managed to damage it bad enough that when I put it back in, a small section broke off, and it just so happened that it's behind the hose and I did not see it during reinstallation, this created a small hole and that was where the hissing was coming from. Now, once I saw that I reseated it using a clamp, the code P0171 stop coming back. Boy oh boy, this POS keeps giving me code after code! Right after fixing Code P0171, Code P0135 follows. It seems codes are lined up, waiting for their turn. However, this latest code P0135 doesn't cause the CEL to turn on. My ODBII just picks it up, I think they refer to it as "Pending" code. Now, my Power Steering line has a tiny crack in the rubber section and leaks. Ordered a line and hope to fix it once for all. This "beater" really beats me up really good. The adventure continues...stay tuned for updates.
 

·
Premium Member
2004 chevy trailblazer_lt
Joined
·
3,001 Posts
Great!

The P0135 means that there is a problem with the heater circuit of the upstream Oxygen Sensor. If you have voltage going to the Oxygen Sensor heater circuit at the plug to the O2 sensor, then it's likely the O2 sensor is defective.

Just as an FYI, avoid the Bosch O2 sensors - the TrailBlazers don't like them. Get either ACDelco or Denso O2 sensors for hopefully many, many happy miles of care free driving.

If you are going to replace one power steering line, save your self some aggravation and replace both the high pressure and low pressure hoses at one time. It's a royal pain in the @$$ job to do, so kill two birds with only one agonizing job rather than doing essentially the same agonizing job twice. Been there.

Good Luck
 

·
Registered
Joined
·
19 Posts
Discussion Starter · #6 · (Edited)
Hi guys! Just an update to my power steering adventure. Unfortunately, I didn't order the other line, so anyway, I put in the new line, which isn't as hard as I watched a few Youtube videos indicate (other than the tight space). There's a small problem, however. Where the line goes into the steering gearbox, there's a small leak, regardless of how tight I screw in the 8MM bolt. On the new line, which is the pressure line, I used the seal that came with it. Now the return line, which is still good, came out with the bad line, and rightfully so because it needs to go in this hole/notch and they are both screwed in together. I don't see a seal on it, but I believe it remains in the gearbox when I took it out with the bad line. Not sure if this is the leaking one, or the new one. The leak isn't bad, just a wet spot, more like just a tiny sip or something. The space is so tight! You can't even see the hole. You just know it's there and try your best to put the two lines in their respective hole. I already took them out once, reseated, and tightened them back on, still that tiny leak. Not sure what else to do now. Maybe just drive it like that and check the power steering fluid level often? Remember, if the old seal was stuck in the hole, I probably wouldn't be able to fish it due to the tight space not to mention I can't even see the hole.

As for the O2 sensor P0135 code, it stops showing up, maybe due to the fact that I'm not scanning it anymore. It actually never triggered the Check Engine Light anyway, just saw it when I scanned it. So, maybe it's not a big deal. However, this other lingering issue is the Stabilitrak, it comes on randomly. I can drive for a few days without it showing up, then randomly, it will show up. However, after turning off the vehicle and the next drive, it disappears. Very unpredictable, I tell ya. Now, I learn to just ignore it.
 

·
Premium Member
2004 chevy trailblazer_lt
Joined
·
3,001 Posts
OK on the work done. When you removed the old PS lines from the steering rack, did the old seals come out along with the tubing? If not, then that is likely the source of your minor PS leak. If the seal was left behind, I have read where people have "screwed in" a bolt that is slightly smaller in diameter than that of the hole, and when they pulled the bolt out, the seal also comes out.

As far as driving around with a Pending P0135, remember that your PCM is not going to be able to accurately measure the amount of fuel being consumed, and you could risk dumping unburned fuel into the catalytic converter resulting in a premature death of the cat converter.

Not sure what to tell you about the Stabilitrak issue other than to check the ABS sensors and make sure they are clean.
 

·
Registered
Joined
·
19 Posts
Discussion Starter · #8 ·
Update: Okay, semi-good news! At least the initial test seems to be "No leak." Here's what I did: I went to Orielly and bought two new seals and put them on. I notice that when you insert/put the lines in, wiggle them back and forth in and gently until they go all the way in. Don't just put the bolt in and start screwing. If they don't happen to seat straight in and you just start screwing them in, a lip may be damaged/torn off and that may create the leak. Look at the seals I pull out. The one on the right is the seal that came with the new pressure line I just bought. Notice the torn lip. The one on the left is the old seal that was on the good, old return hose (which I didn't replace). I can tell one side of the lip is thinner than the other. Not sure if the leak was from which seal, or both. So, I replaced both. After 10 minutes of letting the engine run and making a bunch of turning the steering column all the way to the right and all the way to the left, and after many repeats, it seems to still be dry, so that's the initial test. Tomorrow, after taking it for a real trip, the true test will come. Hopefully, everything is good. The last picture is for anyone who may want to know what product number to look for. They are $7.59 each.

Eye Wood Circle Font Button

Font Wood Hardwood Electric blue Ingredient
 

·
Registered
Joined
·
19 Posts
Discussion Starter · #10 ·
Another question: Do I need to change out the spark plugs if my engine has been running lean for awhile? As I have just purchased the SUV very recently, I don't know how long has it run lean before it was fixed by me. I feel a very slight rough idle after I have driven it for a bit. It doesn't show this very slight rough idle until it has been driven a bit. I'm afraid the lean condition it has been running may have damaged the spark plugs in some way.
 

·
Premium Member
'05 Chevy TB EXT
Joined
·
5,138 Posts
If the computer senses a misfire --- it's not so proud that it won't tell you - quickly!

If they are real Delphi Iridium plugs for this engine, they can usually survive such mistreatment quite handily.

Is the SES light on?
Does the light even work when you start it and then go out in a few moments once the engine is running?​
All the cluster lights will self-test at startup.​

You may know all this --- but there are others who will search this topic and they might need more help than you.
 

·
Registered
Joined
·
19 Posts
Discussion Starter · #12 ·
No check engine light (SES). Not sure if what's inside is Iridium spark plugs. Read a guy doing "Best Spark Plugs" and he gave the best overall award to E3. Gonna try that if I do decide to change mine. Each is like $8.60.
 

·
Premium Member
2004 chevy trailblazer_lt
Joined
·
3,001 Posts
JJ5....NO to the E3 plugs! They might work in a small lawn mower type engine, but they are not known for their successful operation in modern automotive engines. I've read too many horror stories about E3 plugs in other forums such as the Silverado/Sierra forum. If you want to spend that amount of $$$ on something, send the money to me!!! ;-)

These engines are darn picky about the spark plugs that go into them. They strongly prefer ACDelco 41-103 iridium plugs. The vast majority of people (Ravalli Surfer is an exception and one of the lucky few) have driveability problems if they do not use the ACDelco 41-103 plugs. Don't Bosh, Champion, Autolite, Torch, etc. Use only ACDelco 41-103 plugs and you will not be sorry.
 
  • Like
Reactions: Schurkey

·
Registered
Joined
·
19 Posts
Discussion Starter · #14 ·
JJ5....NO to the E3 plugs! They might work in a small lawn mower type engine, but they are not known for their successful operation in modern automotive engines. I've read too many horror stories about E3 plugs in other forums such as the Silverado/Sierra forum. If you want to spend that amount of $$$ on something, send the money to me!!! ;-)

These engines are darn picky about the spark plugs that go into them. They strongly prefer ACDelco 41-103 iridium plugs. The vast majority of people (Ravalli Surfer is an exception and one of the lucky few) have driveability problems if they do not use the ACDelco 41-103 plugs. Don't Bosh, Champion, Autolite, Torch, etc. Use only ACDelco 41-103 plugs and you will not be sorry.
Oh, ok. Will keep that in mind. Thanks!
 

·
Premium Member
2004 chevy trailblazer_lt
Joined
·
3,001 Posts
I'll keep an eye on my mailbox for those greenbacks! ;)

Good Luck!
 

·
Premium Member
2004 chevy trailblazer_lt
Joined
·
3,001 Posts
(y)
 

·
Registered
Joined
·
19 Posts
Discussion Starter · #18 ·
Now that it gets very cold (snow a little where I live), I now get P0442. Just done fixing everything up to this point and now this. Simply too many problems with this POS! I haven't tried the gas cap yet, but the internet tends to think it may just be it. I hope that's it. If not, it might be the purge valve because I just replaced the Canister Evap Valve Solenoid.
 

·
Registered
Joined
·
19 Posts
Discussion Starter · #19 ·
Detroit sway bar links, any good? My POS is having clinky clunky clonky noise in the rear. Feels like something is loose, like something inside the hatchback door, but it's not it. Big clunk, but I already checked the sway bar links, they can turn by hand, but they don't move when you push on them. It's getting colder each day and I hate working on car in the cold. The bump stop (Jounce Bumper) is broken, maybe that's where the sound is coming from?
 

·
Registered
Joined
·
19 Posts
Discussion Starter · #20 ·
On the gas cap, there is a vent hole. Are we supposed to easily blow thru it? As of now, I can blow right thru it. No resistance of any sort at all. If it isn't supposed to be this way, this may be why I get a P0442 code. Can sum1 confirm?
 
1 - 20 of 42 Posts
Top