Whistling Sound

Hey everyone

I’ve been hearing a whistling/howling sound that seems to be related to the accelerator or intake. Truck’s at about 96,000 mi. It happens when I’m barely on the pedal and at a specific pedal position, but will also briefly make the sound under medium load. I took it into a shop who looked at my axels and driveshaft and couldn’t find what it was. I have a stock intake, no k&n filter. I also had my muffler replaced about 3 months ago but the sound didn’t happen until about a month and a half after, so not sure it’d that’s related. Did a throttle body and maf cleaning which also didn’t change anything. I know it’s not wind noise either. Any ideas or recommendations would be appreciated!

 

Power steering pumps can make noise like that. Usually a little moanier sound but worth a listen. Try and power brake the truck and see if you can hear it then. Ruling out driveline if you can make it happen when not moving.

 

Could it be your alternator? I recently changed mine and put a better battery in it and the whining/whistling noise it was making went away? Good luck!

 

Ok I’ll give that a shot. I’ll try to get a video of the sound to see if that helps. The worst part of it is that it doesn’t happen all the time. Sometimes it’ll go a few days with no sound then out of nowhere it returns.

 

If it’s intermittent then I wouldn’t put too much effort into it until it is doing it all the time. Much easier to diagnose.

 

Check PCV valve grommet. Oil residue on hose immediately above it and you may have found your whistle. If so, change it.

 

I replaced my Pcv about a month ago thinking the same thing. No oil on the hose. I replaced the hose as well just incase it was a small vacuum leak.