Funny noises coming from engine

My 350 5.7L in my truck has one problem and that is when it gets up to a certain temperature, it makes a loud humming noise that doesnt seem to affect the performance of the engine it just covers up the sweet 350 motor rumble. So any of you guys have any ideas as to what this noise may be i think it might be a loose vacuum hose somwhere but i'll ask you guys for thoughts before I decide to tear it apart to get to the hoses and find out that wasnt what it was. Your help would be GREATLY appreciated.
Thnak you.

  82Chevy

Just check every accesory reciprocating part. Fan, PS, AC, Alt, Water, etc. etc.

Does it make the noise when you turn the wheel? Hwo about when the A/C is on/off?

  Godlaus

it makes the noise all the time when my truck gets up to a certain temp (ill check out the temp later) and when i turn the truck off the noise goes on for 1-2 seconds after the engine is off.

  82Chevy

Sounds like the fan is overworking. In my expert opinion (not), it sounds like you've got a faulty thermostat. Either that, or you're using the wrong coolant.

Wait for more opinions before you take my advice as granted, though.

  Godlaus

if it was the fan wouldnt it do it all the time? because it starts to do that after about 10-15 minutes of running but it could be the coolant or the thermostat too like you said but i think its probably something so simple its stupid :)

  82Chevy

if it was the fan it wouldnt do it all the time because the fan does not run all the time. It only runs when the engine gets to a certain Temp. My guess would be the bearings in the fan are going bad..

  Erdrickk

hmmm ill have 2 check into that thank u guys 4 your help

  82Chevy

I just saw this, and all I can say is HUH? Before offering advice ALWAYS make sure you understand what the big words you're using mean. If the fan, PS, AC, alternator or water pump are reciprocating, he's going to have a much larger problem than just an annoying little noise. :banghead:

  vwhobo

Actually if your fan is belt driven like mine it is always spinning...only electric fans turn on and off. Nice try though :)

  Golddragoner

What do you drive? An 88 toyota.

  bigfrye

my fan is belt driven.

  82Chevy

Hmm then that would mean when you turn the car on the fan comes on also. try checking it just to make sure. Its probably when something is heating up, one of the parts doesn't fit right or is telling you its ready to give out.

  Golddragoner