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Whining noise at start-up

18K views 18 replies 10 participants last post by  Trailblazer Justin 
#1 ·
I get a whining noise from my 04 trailblazer for about 30-50 seconds after start up. Sort of sounds like a Airplane engine. I have been looking through the threads and noticed that some issue look like the fan clutch assembly. I also notice people complain about a whine which originates from the power steering pump. Is there any way to confirm which one is the culprit? It only happens during start-up. Also I noticed some people talk about changing to efans. What exactly is that and how much does a kit cost?
 
#3 ·
is the whine always followed by a THUMP or more spelled like it actually sounds a FFFWOOOMP .. if so thats totally normal its your AIR system pre charging your catalytic converter with fresh oxygen rich air.

as far as the E-fans they are in production and are availible through PCM4LESS at this link http://forums.trailvoy.com/forumdisplay.php?f=116
 
#8 · (Edited)
OK, I have to add in a question here. I have the exact issue. A whining noise very like a jet engine for about 30-45 sec on a cold start. If I have been driving for longer than a few minutes recently, stopped (ie. to go shopping) and come back in a short time, this doesn't happen, only on cold start. Clutch fan recently replaced... any other thoughts?

Thank you
- A

--- edit:
Leave it to me to add to a 1.5 year old post. If I should start a new thread, let me know. So far I've found: Idler Pulley and Power Steering pump may also be the culprits....
 
#11 ·
Let me see if I get this, though. The fan clutch in question is attached to the cooling fan at the front of the engine, right? If so, is that where the whining noise would be coming from?

In my case it's not -- I popped the hood and listened outside the truck, but on following the sound it was much louder in the driver side front wheel well, and even louder under the truck. That doesn't sound like a fan clutch, and definitely not an idler pulley since I was watching that spin without a sound....

Am I down to power steering pump now? Or something else? I'll keep searching, but how long should I search before just starting a new thread?

Thank you
- A
 
#12 ·
Is that the air pump priming the catalytic converter? Would the whining mean the air pump needs to be replaced? It hasn't always done that - it started a few months after I bought the Envoy used, but I never got an engine light; when I did I took it in, and they replaced the fan clutch, but said the noise was OK until I got another check engine light. I recently got one, but it's for a thermostat issue I'm going to fix myself (P0128).
 
#13 ·
I was able to figure my problem out. It was a secondary air pump. The part is used for emissions from what I could gather. Its basically helps the engine get up to temp or something like that. The part is located under the drivers side frame. I believe that part # is a 2142222 but don't hold me to it. The part has some sort of turbine fan built into it which fails and causes the whine. You will notice it after a cold start.
 
#15 ·
Thanks! I'm finding many of those threads. Don't have that code yet, I think I got that one a while ago, before I decided I need to start doing this work myself. Thank you, Trailvoy. ;)

Should I not worry about this part/system until it throws a code, or does it fall under "can't hurt to check if you already have the 'voy jacked up on that side" (I'm replacing the thermostat soon)?
 
#16 ·
A failed SAIS will just eventually throw a code. If the solenoid valve sticks OPEN it would be bad, but they always fail shut, in reports here. It will cause no driveability symptoms, just a bit more emissions while the engine warms up and gets into closed loop control mode. You can live with the SES light and the code if you're in a place without emissions testing, but it's risky to get complacent about a SES light because it might mask OTHER codes if you're not scanning regularly to see what's up.
 
#17 ·
whining noise (more like a turbo!)

Cindy here, I own a 2004 Trailblazer with almost 80,000 miles and wrote in a forum about my noise. I even posted the noise in a file so people could hear it. Yes, it is my secondary air pump. It is throwing a SES light. I had a kind gentleman show me a picture of where the pump is located and what part number it is and even what website to purchase the part! (thank you Roadie) I am trying to see if we can find the part off a junked Trailblazer first so my son is checking around for one. If not the part will be ordered because the noise is getting on my nerves.......and I don't want to cause any other problem by not fixing this one!
 
#18 ·
Gentleman? We let a gentleman in here? [Whips around to see who's standing behind me.] :hissy:

Anyway, glad to help. Just be reassured that except for the noise at start-up, you're not going to damage your engine or drivetrain by putting off the repair. It won't drive any better when you fix it, contrary to anybody's claims. Just search and get the best price for the part, which is easier because it's not an urgent time-critical repair like some others.
 
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