Whistling noise around 1000 rpm

van1196

New member
Jun 22, 2020
4
0
1
I have an 08 GMC Sierra 2500 HD with about 85,000 miles on it. Noticed a weird whistling noise the other day while pulling out of a parking lot. I only hear the noise around 1000 rpms. I thought it might be the water pump, idler pully, or tensioner so I took the serpentine belt off to see if the noise would go away and confirm my suspicion. I started the truck and got the rpms up around 1000 and the noise is still there. Not sure what else it could be. Any help or advice would be greatly appreciated. Thanks
 

dmaxfireman

'Can do' kind of guy
Staff member
Apr 8, 2007
2,326
1
38
CT
How about some details on the truck, do you have a boost gauge? Any recent work done on the truck? Any modifications to the truck?
 

ChrisPerry

...........
Apr 4, 2016
205
1
18
Ventura, CA
Does it happen rev'd in neutral or only when under load? If under load, stand on the brake and boost it up a little while someone locates sound. Just don't run anyone over.
 

JoshH

Daggum farm truck
Staff member
Vendor/Sponsor
Feb 14, 2007
12,927
18
38
Texas!!!
Drive pressure leaks at the up pipes can cause a strange kind of hollow sounding whistling noise. I compare it to holding a blade of grass between your thumbs and making a whistle like that.
 

van1196

New member
Jun 22, 2020
4
0
1
How about some details on the truck, do you have a boost gauge? Any recent work done on the truck? Any modifications to the truck?
Banks Six Gun with PowerPDA. Doesn’t work right now because it needs a new EGT probe. The PDA reads high EGT temps and the tuner defaults back to stock. I just need to order a new EGT probe from Banks one of these days.
 

van1196

New member
Jun 22, 2020
4
0
1
Does it happen rev'd in neutral or only when under load? If under load, stand on the brake and boost it up a little while someone locates sound. Just don't run anyone over.
It happens around 1000 rpms either in park or in drive. It goes away above 1200 or more rpms.
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)