Very loud noise in 95 Silverado...UPDATE #7
 

Probably about a month or so ago I had my mechanic replace the water pump in my truck. I drove it home and it sat until this morning when I drove it out to get some work done on my trailer. On the way there, I thought the truck sounded like it was making a higher pitched noise than usual. On the way back, it got extremely loud. The best I could describe it would be a WHEEEEEE.... somewhat high pitched. It is separate from the engine noise; as I approached a stop sign, the new noise would die out and the normal engine sound would return. It didn't make it when I was hooking up the trailer or driving really slow.

Truck was running fine otherwise; didn't notice any laboring or overheating or anything. Could this be related to the new water pump? Or is there something else that would make such an odd noise? I thought about the tires, but I don't get why they would get worse on the second trip.

Thanks for any help!

Take the belt off and start it. To make sure it is coming from the engine or something else.

Sounds like a drive belt pulley. What Ruffneck4lyfe said, pull the belt and check for where the sound is coming from.

just dont run for too long without belt.

it does run the water pump!!!

As well as the alternator. Running the engine without the belt will make the engine sustain its self off of your battery. Which will end up draining your battery completely flat if you let it run for too long.

Thanks everyone! I am not mechanically gifted enough to know how to remove a belt. :) It would have to go to a mechanic for any work. Right now I am just stuck between "should I get a newer truck" and "should I put more money into this one?" Of course, I couldn't sell it anyway with the racket it was making...

So if it is the drive belt pulley, is that a major repair? Belt was just replaced about 8 months ago, if that has anything to do with anything.

I went out today to try to get a better idea of what is making the noise. I drove it up the driveway and it sounded normal until I hit about 20 MPH. Then it started making a low pitched howling type noise. I noticed a lot more white smoke coming out the tail pipe too. Could this be a catalytic converter issue? I've noticed for a while a loss of power as well...not horrible but just not quite right.

Hmm ... maybe a wheel bearing then. Is there a way you can use your phone, or camera to record a video of the sound the truck is making? Be it from inside the cab, maybe when the truck is making the sound while idling.

Right off hand, I don't think that this would be a major repair, be it drive belt pulley or wheel bearing. I only judge a trucks total life by its frame rusty. Other than the rust, everything on these trucks is fixable.

I can try taping it. It is only making the noise when it hits 20 MPH though. Would a wheel bearing cause the increase in exhaust?