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2004 chevy trailblazer_lt
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25 Posts
Discussion Starter · #1 ·
Junior Member

2004 Chevy TrailBlazer LT
Indigo Blue Metallic 4.2L I6 4X4
Join Date: Jul 2009
Location: Cordova, MD
Posts: 6

stalling issue

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I did have a mechanic friend of ours do some work to my truck, and he said there was some gunk around the throttle body. He cleaned it and it hasn't stalled since then. (keeping my fingers crossed that was it) Another problem has surfaced though. I now have a whistle when I start the truck in the morning. Sounds like I have a turbo. Only does it when the truck is cold, and after about 25 seconds the whine goes away. Everyone is stumped! He replaced my fuel filter, spark plugs and coil packs (hope that is correct), replaced both 02 sensors and then the noise appeared!! It is running great, just have this turbo sound now when it is first started in the morning or after it sits for a long period of time....... I am at a loss and so are the few people that have heard the noise! (including the mechanic)
 

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2005 chevy trailblazer_ls
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1,113 Posts
Junior Member

2004 Chevy TrailBlazer LT
Indigo Blue Metallic 4.2L I6 4X4
Join Date: Jul 2009
Location: Cordova, MD
Posts: 6

stalling issue

--------------------------------------------------------------------------------

I did have a mechanic friend of ours do some work to my truck, and he said there was some gunk around the throttle body. He cleaned it and it hasn't stalled since then. (keeping my fingers crossed that was it) Another problem has surfaced though. I now have a whistle when I start the truck in the morning. Sounds like I have a turbo. Only does it when the truck is cold, and after about 25 seconds the whine goes away. Everyone is stumped! He replaced my fuel filter, spark plugs and coil packs (hope that is correct), replaced both 02 sensors and then the noise appeared!! It is running great, just have this turbo sound now when it is first started in the morning or after it sits for a long period of time....... I am at a loss and so are the few people that have heard the noise! (including the mechanic)
its more of a supercharger whine than a turbo wine :coffee

this is wats called the idler pulley...simple $21 fix you can do yourself for fun...check out the article under resources and itl explain the whole thing for you...hope this helps :tiphat
 

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2004 chevy trailblazer_lt
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25 Posts
Discussion Starter · #3 ·
more info on whine noise

Thanks for the reply, but it's not that. It's near the transmission transfer case, my mechanic Jeff said maybe the actuator getting worn in?? Man, it does it every time it's just started, cold, the noise starts at the same exact time and lasts for the same amount of seconds each time!! Weird, but puzzling.
 

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Western Canada Chapter
2003
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6,411 Posts
Might have something to do with your secondary air pump


Check the connections. It will be a little tougher to see with the factory stuff in place.:undecided
 

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2004 chevy trailblazer_lt
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25 Posts
Discussion Starter · #7 ·
sound

I can surely try. How should I try to get the sound, with my phone? Not too sure how to get it without other background noise and I have to get it when the truck is cold so I can try in the morning. Thanks for the help with this everyone.
 

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2003 chevy trailblazer_lt
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6,568 Posts
the only way i could think would be if u have a camera that takes video... hit record and put it under the truck, then get in and start it and let it sit there for a while to record... mite not record the sound great... but if mite give us more info then we can get from just text... :m2:

rite now i'm trying to think of everything outside of the engine compartment that could make a turbo whine... and i cant come up with anything...
 

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Banned
2004 gmc
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26,181 Posts
I'm 100% certain that's the Secondary Air Injection turbine pump, mounted to a frame rail under the driver. Only runs on cold starts, and only for 25 seconds. Unless you drive off before it's finished its diagnostic, then it tries again after you're driving, in the next 5-20 minutes typically.

It's loud because it draws 25-30 Amps.

It might be extra loud if it's got junk or especially water in the hoses. Have your mechanic drain them. It could also be going bad. If it dies altogether, it throws code P0410 and sets the SES light.

Blazernut is close, but that's the solenoid valve (item #2) where the OUTPUT air from the turbine pump goes into the exhaust manifold.

The turbine pump is item #6:

 

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2004 chevy trailblazer_lt
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Discussion Starter · #10 ·
thanks

:hail: If this is it, I will send you a great big Thank YOU!! I'll show Jeff the forum post, and see when he can examine my truck. It will be great to finally find the cause of this noise.
 

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2004 chevy trailblazer_lt
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25 Posts
Discussion Starter · #11 ·
noise

Trying to upload a file from my camera with the noise my truck is making. It gave me an error that a security token is missing? Can anyone help? Thank you!
 

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Banned
2004 gmc
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26,181 Posts
Oh, yeah. That's the turbine air pump. Sounds like it had been full of water in the past and the bearing is unhappy. Pull the hoses and see if anything falls out.

The pump can fail altogether and it will have ZERO effect on drivability or emissions other than at a cold start. Then the SES light will come on and you'll get a P0410 code, but it won't affect anything except you'll fail an emissions test if you're in a place that requires them. You can save up for a new pump if cost is an issue, or keep looking on Ebay.

It's GM #12574379 or ACDelco #215-454, $172 at rockauto.com
 

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2003 gmc envoy_slt_xl
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270 Posts
Oh, yeah. That's the turbine air pump. Sounds like it had been full of water in the past and the bearing is unhappy. Pull the hoses and see if anything falls out.

The pump can fail altogether and it will have ZERO effect on drivability or emissions other than at a cold start. Then the SES light will come on and you'll get a P0410 code, but it won't affect anything except you'll fail an emissions test if you're in a place that requires them. You can save up for a new pump if cost is an issue, or keep looking on Ebay.

It's GM #12574379 or ACDelco #215-454, $172 at rockauto.com
I agree with The roadie.:iagree::iagree::iagree:
Excellent recording Cindy.
 

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2003 gmc envoy_slt
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361 Posts
I'm 100% certain that's the Secondary Air Injection turbine pump, mounted to a frame rail under the driver. Only runs on cold starts, and only for 25 seconds. Unless you drive off before it's finished its diagnostic, then it tries again after you're driving, in the next 5-20 minutes typically.

It's loud because it draws 25-30 Amps.

It might be extra loud if it's got junk or especially water in the hoses. Have your mechanic drain them. It could also be going bad. If it dies altogether, it throws code P0410 and sets the SES light.

Blazernut is close, but that's the solenoid valve (item #2) where the OUTPUT air from the turbine pump goes into the exhaust manifold.

The turbine pump is item #6:

Is the Secondary Air Injection system an '04 and up system? My '03 has a plate over the port where Blazernut shows the solenoid mounted. He has an 03 but I guess the picture could be from a different year. My '03 Helms doesn't show anything about Secondary Air Injection or a P0410 code.
 

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Banned
2004 gmc
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26,181 Posts
You're right. The system was added in 2004 to pass some new EPA requirement. It's not as if most people are letting the vehicle warm up for even 30 seconds on most cold starts, so the system usually doesn't even get a chance to complete its sequence. A total waste.
 
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