Thanks to whoever added my supercharger!

[jaredking733]

Ok, but seriously..

Over the past few weeks, I've been hearing a noise that sounds just like one. A few weeks ago, it was only about once a week, but is now every morning. It only happens when the truck is started after sitting for several hours (with the exception of one time I can recall) and goes away after completely after few miles of driving.

We had a couple of warm says recently and it still did it so I feel like that rules out the cold weather being the cause.

The sound changes with RPM. Low pitch/no sound at all at idle. High pitched right before the transmission shifts into the next gear, and gradual pitch increase everywhere in between.

Turning the wheel doesn't seem to affect the sound.

My first thought was power steering pump about to go bad, but the steering is totally normal. That may not matter and they may function perfectly until they don't. I just don't know. Also, turning the wheel doesn't affect the loudness or frequency of the sound.

I've searched all over and have found everything from power steering pump to a pulley to the transmission pump going bad.

Anyone have any ideas with it may be in this case?

 

[Mynameistommy510]

Ok, but seriously..

Over the past few weeks, I've been hearing a noise that sounds just like one. A few weeks ago, it was only about once a week, but is now every morning. It only happens when the truck is started after sitting for several hours (with the exception of one time I can recall) and goes away after completely after few miles of driving.

We had a couple of warm says recently and it still did it so I feel like that rules out the cold weather being the cause.

The sound changes with RPM. Low pitch/no sound at all at idle. High pitched right before the transmission shifts into the next gear, and gradual pitch increase everywhere in between.

Turning the wheel doesn't seem to affect the sound.

My first thought was power steering pump about to go bad, but the steering is totally normal. That may not matter and they may function perfectly until they don't. I just don't know. Also, turning the wheel doesn't affect the loudness or frequency of the sound.

I've searched all over and have found everything from power steering pump to a pulley to the transmission pump going bad.

Anyone have any ideas with it may be in this case?

Your alternator may be on its way out. Or maybe a vaccum leak? So it's a whinning sound? Or a vaccum sucking sound?

 

[jaredking733]

Your alternator may be on its way out. Or maybe a vaccum leak? So it's a whinning sound? Or a vaccum sucking sound?

Sounds just like a turbo winding up on on a small turbo diesel engine.

It only happens the first few miles of the drive so I don't suspect a vacuum leak (though I could be wrong).

 

[jaredking733]

There is a small bit of a flutter or rattle sound with it as well.

 

[Riceye]

A/C idler pulley, down under. Not the pulley on the compressor.

 

[02SE]

Without being able to hear it, all we can do is guess.

I would suggest taking it to a skilled Mechanic, that has experience with NVH (noise, vibration, harshness) issues.

 

[AZ4Running]

Sounds like it could be a belt pulley bearing going bad. Remove the belts and spin all the pulleys listening for a noisy one, also check the alternator using the same method.

 

[jaredking733]

Just popped the hood for another listen and I can hear a very high pitched whistle on the passenger side of the engine bay towards the front.

 

[JayRolla]

Leak at the air intake or vacuum line?

 

[nevada]

Just popped the hood for another listen and I can hear a very high pitched whistle on the passenger side of the engine bay towards the front.

as said above, pull the belts, and spin the pulleys by hand.

 

[jaredking733]

as said above, pull the belts, and spin the pulleys by hand.

Will do in the morning when the sound is most prevalent. I'll report back with results.

 

[Mynameistommy510]

Hit the idler pulley (lonely pulley with tension adjustment) with some WD 40 and see if the noise goes away. Then either replace it if it's bad or get some real lubricant on it.