Top End Noise?

[LeoneSM]

My 87 Jimmy just developed this strange noise. It's more of a whine than ticking.

It appears to be coming from the top end but I'm not sure. It's not really RPM specific and seems to come and go. Sometimes when it's happening I can blip the throttle and it goes away. It might happen once a week or it might do it every time I crank the truck.

It sounds kinda like the water pump is going but it's less than a year old and I really think the noise sounds more like it's coming from under the manifold.

You guys have any idea what it could be or what I need to look at?

 

[Fastereddie]

That sounds strange for sure. First thing I would do is remove all the belts and see if it goes away.

 

[Fastereddie]

Then my next guess would be starter bendix staying engaged or trans pump or converter.

 

[rampage]

Short piece of wood (like a cutoff broom stick handle) pressed against your ear and placed against different parts will help you isolate it.

 

[dyeager535]

The noise I hear is a much louder buzzing, although in the background it sounds a bit like a pulley squeaking. Which one is it?

By the way, for anyone that likes to amplify their hearing, you can buy stethoscopes for stupid cheap. Not sure how good they are for sound compared to what a doctor will actually use, but can easily hear my heartbeat, plus a variety of engine noises: http://www.ebay.com/itm/Family-Medi...hash=item3af036d73e:m:m2SPvB7O1gCOFO1l36Yq3qw

 

[LeoneSM]

I actually just bought a mechanics stethoscope off of Amazon just before you posted that. My initial thought was A/C compressor but I removed the belt and the noise is still present. The belt is off in that video. It really sounds like it's in the motor but I've never heard a sound like that from the valvetrain and don't think it's possible. Maybe my ears are lying to me. Hopefully the stethoscope will point me in the correct direction

 

[diesel4me]

Have you tried putting the air cleaner lid back on the way it was intended to go ?...hard to tell by the video just what the noise is,but it could be the fuel injection throttle body suction your hearing..maybe the intake gaskets are leaking ?..

It does not sound like an "engine" noise,excepting maybe a vacuum leak--it is more likely a accessory like an alternator or P/S pump --as suggested ,take the belt off and start it up and see in it still makes the noise..

 

[LeoneSM]

I finally got time to mess with it today. I took the stethoscope and poked around the engine. Sound sure seemed like it was coming from the manifold and I kept focusing on the front of the manifold every time I'd back up and try to pin it to a certain area. I drive the truck daily and have actually been carrying the stethoscope with me because the sound seemed to come and go and never wanted to do it parked in the driveway.

I accidentally hit the PCV valve and the tone changed. There was a small crack in hose going from the PCV to the throttle body. Problem solved. I'm glad it was simple but it was driving me nuts!