Well while we're on the topic (couldn't justify making a new thread for this), mine has a whine too. It seems to come from in the front of the engine, almost behind the radiator. It does it during idle of if I rev it up, D/N/P doesnt matter. Once it warms up a bit though, it seems to go away.

I was thinking t-chain, but I don't know.

 

well i am using 20w-50 penzoil and an stp filter, my oil pressure is almost to the red mark on my gauge(looks like over rev on rpm guage-all the way to red, is that a sign of something going bad?

 

Try using a lighter viscosity oil. I still run 10w30 Mobil 1 in mine and it hovers nicely around 40-45 lbs. Using a heavier oil, I would assume, is causing the oil pump to overwork itself. If you are using heavier oil to stop a leak somewhere, trust me, It is cheaper to fix the leak and use the right oil. However if you are using it to keep it from burning oil, I would just use some lucas oil additive, or just a gas can and some matches (one on a still day)

 

dude 20w-50? yeah great idea. nothing better for your truck than robbing it of power and gas mileage. those engines are designed for 5w-30. with that many miles the thickest i would go is 10w-30. as for the whineing, its a pully of some sort. altenator or power steering are the common componets to make noise. both easy fixes. and please change your oil to something thinner before something snaps in your engine from the huge amount of stress its under

 

My pet theory is that when the truck is cold, the IAC valve is opened all the way, and the swirling of air around it causes the loud wining sound.

 

is 20w50 really that bad for a 5.2 v8 with 161000 miles what should i be running?

 

5w30 or 10w30 is the norm

 

I use 15W50 in my 96 with 110000 miles on it and it does just fine, no noises.
Used 20W50 in my 87 since new and no problems at 170000 miles.
I wouldn't use either in a new vehicle now days though.

 

Hmm this whining noise I am also trying to figure out,

Cant really make it make the noise when sitting. almost has to be taking off to hear it.
Will remove belt and run down the drive one time without heating up . see if I hear it..