Front engine sounds?

[lowesguy]

Took the truck for a short ride today,strange sound coming from front side of engine,does a click ,click,then a whirling siren sound,like a bearing going south,lifted the hood to listen and seems on the left side of engine,hard to tell what it is? I suspect alternator bearing, smog pump,or water pump bearing,comes and goes,thought it was loose belts,but I tightened them ,still the sound happens,only once warmed,I plan on taking the belt off and hand spinning each accessory,see if I can hear it. weirdest sound I've ever hear on my truck in 20 years!
did get some nice pics thou!

[geezer#99]

Take the belts off each suspected culprit and then test to narrow it down.
Got a pic of the motor?

[lowesguy]

Here,all accessories have been replaced years ago,so they are not original,sounds like the smog pump??? we shall see!

[Malo83]

I'd like some info on your AC compressor setup

[geezer#99]

Speaking of a/c set ups, it could be the compressor switch clicking and the compressor making the noise. Just unplug the wire on it to check.
And apoligies for not commenting on the AWESOME PICS of your truck.

[lowesguy]

Sound is not coming from a/c side at all, has to be one of the 3 I mentioned before,as far as the a/c setup,that's the way the truck came when I bought it 20 years ago,think it was an add on from PO.can you believe that paint job is 9 years old? truck sits outside,it has just the right amount of patina to make it look old,1978 c-20 Custom Deluxe,front springs are HD,about 2" higher,rear is stock.
Did get a 5 min compliment from a guy from Wisconsin at the gas station, he told me they don't see these trucks anymore due to the salt rusting them away.

[geezer#99]

THe a/c set up looks just like the one on my 84.

[lowesguy]

84? sounds about right,I've never seen factory set ups that look like it,its non opt now, worked 9 years ago,has a leak somewhere? hoses probably I had the compressor changed 12 years ago. probably have put 10k miles on the truck in 10 years,it has around 135k on it now,sadly I will be selling it on ebay in the future,I just don't drive it anymore and hate to see it wither away parked on the street,hopefully a collector will take care of it!

[lowesguy]

Well its the air/smog pump,took it off today totally shot,tried to gut it,but its to far gone,If anyone has a spare laying around and needs some play money PM me thanks its a 78 350 5.7 V8,or $74 at rock auto.