whirring noise

PATRICKH · Post by **PATRICKH** » Fri Feb 15, 2008 10:14 am

Ok, when I drive my truck for any period of time, and say, I stop at a light or park it and sit with the engine running, I can hear a loud whirring noise. I know it's not the fuel pump. Whatever this is, it switches on, runs for about 45 seconds, then switches off. A guy I work with has a 2001 Blazer (same year as my CC) and he does not hear it on his truck.

Is this something else involved with the fuel system, or ???

Edited title. There are no stupid questions, only stupid people ...who do not ask questions-HJ

killian96ss · Post by **killian96ss** » Fri Feb 15, 2008 12:47 pm

A/C clutch?

Steve

PATRICKH · Post by **PATRICKH** » Fri Feb 15, 2008 2:30 pm

No, It's coming from under the truck. Sounds stupid, but it does sound like a pump.

Post by **HenryJ** » Fri Feb 15, 2008 3:45 pm

Check to see if your throttle cable is resting upon the PCV vent line. Tie it up or insulate it. The vibrations transfer to the cab making it sound like a little motor clicking through the dash.

green02crew · Post by **green02crew** » Fri Feb 15, 2008 6:08 pm

Just a simple thought but I would think fan.

PATRICKH · Post by **PATRICKH** » Fri Feb 15, 2008 8:32 pm

No it's not a rattle. It sounds like a pump motor running. It's not coming from under the hood. That's ok guys, nothing seems to be wrong, just wanted to see if anyone else encountered something like this.

Post by **HenryJ** » Fri Feb 15, 2008 8:37 pm

Check the throttle cable. I thought I heard a motor running too. Sounded like a tiny bike with cards in the spokes. I was sure it was in the instrument cluster or that area.

Cajun · Post by **Cajun** » Sat Feb 16, 2008 7:05 pm

I have a similar noise coming from behind the dash, instrument/radio/AC controls area ans sounds like the spinning of a CD or DVD player searching for information on a disk. It seems to happen most likely on deceleration. I thought it may be the CD changer so I unloaded all CDs and turned the unit off...I still have the noise...

What do you think?

roadrunner · Post by **roadrunner** » Sat Feb 16, 2008 7:12 pm

Cajun wrote:I have a similar noise coming from behind the dash, instrument/radio/AC controls area ans sounds like the spinning of a CD or DVD player searching for information on a disk. It seems to happen most likely on deceleration. I thought it may be the CD changer so I unloaded all CDs and turned the unit off...I still have the noise...

What do you think?

I have that noise in mine too. I have stock cd-am-fm. Cooling fan on back of the radio. Noise is audible with radio on or off.

Cajun · Post by **Cajun** » Sat Feb 16, 2008 7:18 pm

I have that noise in mine too. I have stock cd-am-fm. Cooling fan on back of the radio. Noise is audible with radio on or off.

I to have the same stock unit. Is there a cooling fan on the back of the unit?

roadrunner · Post by **roadrunner** » Sat Feb 16, 2008 7:26 pm

Yup. As viewed from the front it's on the upper right hand rear corner about 1 1/2 inches in diameter.

Cajun · Post by **Cajun** » Sat Feb 16, 2008 7:29 pm

Thanks! I'll check it out. Maybe the whole unit will die and I'll just have to replace it!

Post by **HenryJ** » Sat Feb 16, 2008 7:50 pm

Did any of you check the throttle cable? I have been through this : Noise from intake?

Cajun · Post by **Cajun** » Sat Feb 16, 2008 7:52 pm

under the dash or under the hood?

Post by **HenryJ** » Sat Feb 16, 2008 7:56 pm

Under the hood.

HenryJ wrote:Check to see if your throttle cable is resting upon the PCV vent line. Tie it up or insulate it. The vibrations transfer to the cab making it sound like a little motor clicking through the dash.

roadrunner · Post by **roadrunner** » Sat Feb 16, 2008 7:57 pm

HenryJ wrote:Did any of you check the throttle cable? I have been through this : Noise from intake?

Yup. In my case it was the radio fan.

Post by **HenryJ** » Sat Feb 16, 2008 8:27 pm

Hmm... Pretty sure my 2001 does not have a "radio fan". That sound went away on mine when I tied the cable up off of the PCV line.

Those Blazers and Bravadas with auto-climate control do have a little fan under that vent in the headliner above the drivers door. This gathers debris and can get noisy pretty quickly. Mine has it since I installed the Bravada upper wiring harness. I unplugged it pretty soon after the install do to the noise.

Cajun · Post by **Cajun** » Sun Feb 17, 2008 7:46 am

Yup. In my case it was the radio fan.

What did you do to fix it?

JaVeRo · Post by **JaVeRo** » Sun Feb 17, 2008 9:57 am

Here is a picture of the fan on my 2001

I just happened to have the radio out trying to get to the HVAC mode actuator.

James

Post by **HenryJ** » Sun Feb 17, 2008 10:06 am

Interesting. Mine must have been pre production.

JaVeRo · Post by **JaVeRo** » Sun Feb 17, 2008 10:51 am

The tag on my radio says "Manufactured 05/15/01"

I bought the truck in Sept 01 so it was late in the model year.

James

roadrunner · Post by **roadrunner** » Sun Feb 17, 2008 10:54 am

Cajun wrote:
Yup. In my case it was the radio fan.
What did you do to fix it?

Nothing except ignore it since it does no damage. I tried oiling it with a verrrry light grade oil but it made no difference. It doesn't run all the time on mine so must have some sort of thermostat control. BTW I lost the left side speakers on my radio and bought a used unit out of an 02 CC from another member on this site and it is identical to mine complete with cooling fan. Date of manufacture on my original radio is 02/06/01.

drperry · Post by **drperry** » Sun Feb 17, 2008 11:17 am

Might depend on the model of radio you have...

My 2005 factory CD Player doesn't have a fan...

border man · Post by **border man** » Sun Feb 17, 2008 1:40 pm

Sorta off-topic, but the title applies in my case. Here recently, I have been getting the whirring noise in my 8 year old truck. I know exactly where it is coming from too. It's the AC/Heater blower fan. Sound like maybe the fan is out of alignement and rubbing on something. Question is, is it serviceable? Do I have to tear my dash apart to get to it? or do I suck it up and live with it?

JaVeRo · Post by **JaVeRo** » Sun Feb 17, 2008 9:53 pm

border man wrote: Here recently, I have been getting the whirring noise in my 8 year old truck. I know exactly where it is coming from too. It's the AC/Heater blower fan.

My wife claims she hears a belt squealing and said it's not coming from the motor, it's coming from the dash (her words, not mine). It's another one of those noises that only happens when I'm not around to hear it. She swears it has something to do with the heater.

If you find your fix, let me know what it was.

It's really quite comical watching her get mad when she can't made the truck repeat a problem so I can witness it.

James

green02crew · Post by **green02crew** » Sun Feb 17, 2008 11:51 pm

Mine makes a small squealing noise when the heat is on and set to partial heat partial cold. Seems the mixture makes it noisy but just heat not a peep.

drperry · Post by **drperry** » Mon Feb 18, 2008 4:03 pm

When the temperature gets really cold outside, it's going to squeal

roadrunner · Post by **roadrunner** » Mon Feb 18, 2008 4:03 pm

It's really quite comical watching her get mad when she can't made the truck repeat a problem so I can witness it.

James

Yeah, I remember all those frustrated customers when I used to work in a dealership in my younger years. Still don't know if many of them believed me when I told them I would investigate and didn't doubt them. Many dubious looks.