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2006 chevy trailblazer_ls_ext
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Discussion Starter · #22 · (Edited)
Update...

Today I finally fixed the whine!! OMG silence sounds so good!! I replaced the same idler pulley as everyone elses. The bearing inside it was bad. I said "my" noise was on the drivers side. Yes the idler pulley is on the drivers side. It is located between the alternator and A/C. Easy to replace. 3/8" drive breaker bar to remove the belt, 15MM socket with 18" ratchet and 10 minutes. Simple fix. I know someone suggested this, I thought the tensioner pulley was the same as idler pulley. Wrong. I read an enormous amount of threads and found they were two different pulleys and where this was located. Spent my $16.00 on pulley from autozone. Perfection!!!

Now about the other... I finally threw a code. 0506... from what I was told from AutoZone it is DIRTY THROTTLE BODY. I was actually going there to buy TB cleaner and the light came on... While I was there I bought AC Delco Iridium Spark plugs and I'm going to replace them too while I have access.

I cannot do this until thursday due to time, so I'll post the results then...

Thanks so much for all the tips
 

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2006 chevy trailblazer_ls_ext
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Discussion Starter · #23 ·
Idle issue update...

Today I cleaned the Throttle Body and installed the new AC Delco Spark plugs. I followed the directions on a previous post about the throttle cleaning. It fit exactly (thanks ). The Throttle Body didn't look that bad until I removed it and the back was absolutely filthy. It took about 30 minutes of spraying, scrubbing and soaking. I put it back on and so far so good. Thanks Roadie!! You rock.

About the Spark Plugs... I checked the gap on the new ones, they were all gapped correctly and ready for install and I used the anti seize on them. I wish who ever installed the previous ones had done the same.... they were EXTREMELY tight but with alot of patience... I was able to remove them with any issues.

Thanks everyone for the advice and "How to Posts"
 

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The idle should ALWAYS be rock solid at 600-625 RPM. Any time it dips below that when a load gets added, whether it's from the alternator or the AC compressor, the throttle body should instantly compensate. If the RPM dips to 500 or 550, and this is a lot easier to see on a scangauge or scan tool than the tach, then the alternator isn't going to keep up and stay in voltage regulation around 14V. Then the voltage will dip to whatever the battery can put out, like 12.1 to 12.5.

But my money is on a dirty throttle body when the idle dips, unless you have a true misfire. But misfires are usually bad all the time and then you get a flashing SES light, or bad for a short enough time that you get a P030X code for an identified misfire.
06 trailblazer. Lights dimming, engine Kept cutting off when I came to a stop or let the engine idle. Was basically having to operate the gas and brake with 2 feet. Cleaned the throttle body, lights quit dimming and no more low idle or engine stalls.

Clean your throttle bodies yall. Super easy, took about 25 minutes.
 

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'05 Chevy TB EXT
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I am not trying to lead anyone to say it was the alternator... but I'm open to suggestions.

BTW My TB has the same whine as the rest. Mine sounds like it is on the right side... I'm again thinking alternator...Yes the whine is RPM controlled.
If the whine is not mechanically induced, it might be the High Freq "excitement" of the alternator as it is fed 400Hz to artificially induce the alternator to produce higher voltage to compensate for a low --- or going low --- battery voltage.

There is an induction device mounted on the negative battery cable that "reads" the amperage and checks to see if the battery is dropping precipitously or the alternator can keep up with current demands.

IF you have a low amperage alternator - and mine in a 250Amp unit for just that reason (high amps-capacity) to make up for all your devices that draw the battery down ... and it cannot keep up ... then I can see the problem you are seeing.

I have heard that there is a 'shedding load" program to delete certain, non-important devices when the alternator cannot keep up and maybe you are pushing that script into trying to save the engine running at all costs --- I'd like to be there to test this for you - but alas!

BTW ---> has the induction device on the negative battery cable been removed/damaged/unwired/otherwise modified?
Is there a new cable without the device on it?
Just asking!
It needs to be there and working for all to stay 'well' in your charging system.
Assumedly --- I am talking of something I am not sure even exists on your vintage vehicle - but it is on mine so I made that extension of logic.
 

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'05 Chevy TB EXT
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OK --- I see this went to the old admonition to clean your throttle bodies.

That's good - but with only clean air going through them, for some reason OUR TB's seem to have particularly dirty throttle bodies all the time.

Ever wonder why our vehicles should always be the BEFORE part of a poster child?



(wait for it)



(here it comes)




Is your PCV system dumping brown sludge into the sound chamber (the black box over the valve cover) thusly getting into your throttle butterfly?
 

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2003 chevy trailblazer_ls
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I have a 2006 and my issues are similar to several others but still unique. My wife informs me that when she was sitting at a stop light she says the engine acts like its going to die and the lights dim. So I drive it a cpl days and nothing. I took it to Auto Zone to see if any Engine codes were stored and "no codes". Finally it happened for me. I was sitting still and the engine RPM's dropped to 3-400. The lights dimmed. The Voltage gage showed 9.5 -10. The motor was NOT missing. It was running smooth. Weird.

I have a new battery installed. I put a voltage meter on the battery and was messing around turning things on and off... The normal reading with low "draw" was 13.9 - 14.1. I then turned EVERYTHING on I could and the idle dropped low again. The test reading was all over the place. Constantly moving from 13.75, 3, 10, 0.22, 5, etc. It bounced all over. So I thought alternator. So I went back to Auto Zone and had them run Diagnostic. The Alternator passed all tests. Weird

Now I am confused. I have no issues if I am just running "normally". Lights, radio, and heat on low ( 1 or 2) however if I turn on the heat or defrost to 4 or 5 when idle ling at light then it will drop down again and act like it wants to die.

I don't have the money to throw parts at it. I am not trying to lead anyone to say it was the alternator... but I'm open to suggestions.

BTW My TB has the same whine as the rest. Mine sounds like it is on the right side... I'm again thinking alternator...Yes the whine is RPM controlled.

Pep Boys says they will test the alternator for free if I take it off, but want $25 to test it on. It doesn't seem that easy to take off. I have basic to moderate skills.

Does this sound like anything to the Masters on here?

Mileage is at 110K if that matters. Battery is less than 2 wks old. Just replaced original battery due to cold temps.
STAY AWAY FROM PEP BOYS, they will sell you anything but you went in for. especially Garner, NC. go to advance or auto zone. at least they are honest, but still want to sell ya something. better than pep buys!!!!
.at least these guys and gals use vaseline!
 

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I have a 2006 and my issues are similar to several others but still unique. My wife informs me that when she was sitting at a stop light she says the engine acts like its going to die and the lights dim. So I drive it a cpl days and nothing. I took it to Auto Zone to see if any Engine codes were stored and "no codes". Finally it happened for me. I was sitting still and the engine RPM's dropped to 3-400. The lights dimmed. The Voltage gage showed 9.5 -10. The motor was NOT missing. It was running smooth. Weird.

I have a new battery installed. I put a voltage meter on the battery and was messing around turning things on and off... The normal reading with low "draw" was 13.9 - 14.1. I then turned EVERYTHING on I could and the idle dropped low again. The test reading was all over the place. Constantly moving from 13.75, 3, 10, 0.22, 5, etc. It bounced all over. So I thought alternator. So I went back to Auto Zone and had them run Diagnostic. The Alternator passed all tests. Weird

Now I am confused. I have no issues if I am just running "normally". Lights, radio, and heat on low ( 1 or 2) however if I turn on the heat or defrost to 4 or 5 when idle ling at light then it will drop down again and act like it wants to die.

I don't have the money to throw parts at it. I am not trying to lead anyone to say it was the alternator... but I'm open to suggestions.

BTW My TB has the same whine as the rest. Mine sounds like it is on the right side... I'm again thinking alternator...Yes the whine is RPM controlled.

Pep Boys says they will test the alternator for free if I take it off, but want $25 to test it on. It doesn't seem that easy to take off. I have basic to moderate skills.

Does this sound like anything to the Masters on here?

Mileage is at 110K if that matters. Battery is less than 2 wks old. Just replaced original battery due to cold temps.
sounds like the switch for ur heat/ac might be going bad/drawing too much power when switched to higher speeds…or the wiring to the resistor is heating up and drawing too much power….these things have everything regulated through the pcm and it has some sort of charge controlling crap in it so that it won’t turn in the alternator to charge all the time so it helps save horsepower somehow…I’m not sure how it works but it’s just another thorn in the side of the owner…when I first got my 05 trailblazer, it melted the harness to the resistor and fan in the passenger side behind the glove box…so I got another one…same thing happened…so I cut the ends of the melted harness off and put my own clips on and made it work….it worked for a few months then melts those off….what finally seemed to work was adding another foot of wire and putting a new harness end on it and then replacing the resistor…it seems the extra foot of wire prevents the harness end from heating up too badly and melting it…the resistor is a problem in these things…idk why they went all electronic with the heating cuz in the middle of nowhere and -28 degrees out and the heater decides to stop working almost made a bad situation much worse…the people who engineer these junk vehicles today are intentionally making them cheap and impossible to work on…there is no reliability with vehicles anymore and is why I won’t buy anything new …when I sell my trailblazer I’m getting a 98ish Dodge Ram with the 318 cuz they’re the last reliable model ever made…
 

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'05 Chevy TB EXT
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Hey, Chewy --- sorry for your problems.

I suggest with that attitude that you set your car on fire and cook some S'mores on it.

That's all this car is worth to you anyway.
 
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