This is for a 97 s10 Blazer 4.3 with air. I am plagued by engine noise/squeaks in the drive belt accessories. At first it came and went for two years so I resently replaced the pulley on the tensioner. Now there seems to be at least two squeaks. How do I determine what they are? The belt is on straight.

 

any play towards the front and rear of the truck on the tensioner?

 

I use a old broken hotdog stick to find where noises are coming from in the engine bay.

It a piece os metal about 2 feet long. One end has a wooden handle, the other end used to have two tongs, they broke off and now its just a piece of metal about 2' long stuck into a wooden handle. I stick the metal end on the suspected bad part, put my ear (just in front of the ear cannal) on the wooden part. The nosie travels up the metal rod through the handle and into my ear. Move it around and you can find/hear grinding bearings, squealling parts etc.

Its hard to tell if the water pump, alternator, a/c or one of the pulleys is squalling, put the diagnostic tool on the parts and listen. You'll now, it will be very different then the rest of the parts.

Or you could use a stethescope, like nurses use. Same effect. A length of vacuum hose does the same thing. However the trouble with the stethescope and vacuum hose is you have to hold them on the port, that can be dangerous when the engine is running. Your shirt could get cuaght in the belt and suck your hand/arm/head in. Be very concientious of the moving parts. Your life depends on it.