Does this sound familiar? Engine squeal.

I can not find the source of this annoying noise.
Does this sound like a bad alternator bearing?

Dang Dmitry. Ain't got no clue.

Wow, that's a spooky sound. Very distinctive, someone is bound to know what it is.

Take the belts off and run the engine. Might be alternator or water pump or other driven accessory.

Stan take a very long screwdriver and it put on all things turning with your ear on the other end check the belt tensioners first they make some crazy sounds

LARRY70GS wrote:

Take the belts off and run the engine.  Might be alternator or water pump or other driven accessory.

Hm. For how long is it safe to run the engine without coolant circulation? And why? Is it even possible that engine itself makes this sound?
I think it is definitely something belt driven, but still - it leaves me with 5 suspects Ok, maybe 4 - I think I can safely rule out the A/C compressor.
On the second thought... I think I can take the belt off when the engine is cold and safely rev the engine up couple of times - enough to make sure the noise is gone, or to find out something truly wonderful )

71stagegs wrote:

Stan take a very long screwdriver and it put on all things turning with your ear on the other end check the belt tensioners first they make some crazy sounds

In fact, I have a special stethoscope, but, evidently, it's not enough - a pair of trained ears is a must-have component. To me everything in there is loud and noisy, I can not specify any distinctive sound source. Besides, only idler pulley and alternator can be inspected with a stethoscope. Or I simply don't know how to use it )

You can run the engine for a minute, long enough to tell if it is a belt driven noise, then just turn everything by hand. The problem accessory should be evident.

Sounds like more than one issue.

1) Intermittent screech after throttle blip: I'd look at the PS pump.  Water pump failing sound I'm familiar with is more like marbles in a can.

2) do you know for sure you do not have an intake manifold or vacuum harness leak? That 3800 is kind of whistle-y.

3) probably because of where it is -- when my alternator has failed in the past, the bad bearings sound like a bad/spun engine bearing, a squeal that is really disheartening because that's what you think it is when you first hear it. truly gut-wrenching squeal...

4) try to rule out the AC first.  In "auto" mode the AC runs almost all the time.

Really, I'd be thinking of re-doing any R&R on the intake (intake manifold, air cleaner, even  check air cleaner housing--is it installed correctly) and turning every pulley, except the crank pulley, by hand to find any roughness or grind and replacing the pulley or driven part. I figure it would take me all day to find this by myself. Even using the long screwdriver, a stethoscope, or a piece of cutoff garden hose.

Stan you will hear the grinding with a simple screwdriver using a long one you can reach all of them have done it many times it works quickly

Mine is just fine I believe. Don't have such a noise

Bump -- so, Dmitry, what did you find?

So far - not much, did not have time.
Yesterday I replaced the idler pulley (2 minute job) and it turned out that its bearing was dry and with a noticeable play. Alas, the idler pulley was not the source of my squeal, but the overall noise in the engine compartment dropped a notch.
I'm planning a massive under-the-hood job: going to replace upper intake manifold (not just gaskets - got the  brand new one), valve stem seals, alternator bearing, check up the vacuum lines and many more small things. I hope the new alternator bearing will fix my squealing.

Will report back on my progress.

good luck

Ok, it is something related to the PCV system.
I revved up the engine to produce the squeal and tried to open the oil cap - the squeal stopped immediately.
Good to know it's not failing PS or water pump.
I hope this problem will go away as soon as I install my new upper intake manifold (new PCV valve included).

Upper intake manifold replaced - no more squeals, woo-hoo!

DeepFrozen wrote:

Upper intake manifold replaced - no more squeals, woo-hoo!

From this:

...to this:

Congrats on finding the problems.

Albertj

Thanks, guys.

And now - my old intake manifold.



When I flipped it over, I just couldn't stop screaming )))