whining/squeaky sound from engine

[roberttran]

When I start up my car in the morning I hear a whiny/squeaky sound from under the hood. When I open up the hood, the sound of the engine washes it out. Could this be the belts, water pump or alternator?

-Robert

[Hollywood Hamilton]

Belts ot vac leak. That's my long distance diagnosis

[BMWgr]

Belt tensioner could be it too

[roberttran]

How would I confirm which one it is?

-Robert

[roberttran]

bump

[Gofast]

Does if you rev the engine, does it go away or become spotty?
It's probably the belts wearing out. This often becomes apparent when it gets colder, In fact I just replaced my belts and readjusted my tensioners this past weekend.

FYI, vaccum leaks usually sound more like a whistle.

[roberttran]

Yeah, the noise goes away after I drive around. How do I adjust the tensioners? I think the belts were replaced about 15k miles ago by the previous owner though.

Thanks,
Robert

[Lawrence1]

my car does this too but only on some mornings ... not all the time and it's only for the first 2 mins or so. the belts seem out of the question in my case though, since they were replaced less than 5k miles ago.

any other ideas on what might be causing this?

[Gofast]

The belts may very well have worn out in 15K miles. Look at the belts closely, you'll see little cracks on the inside ribs of the belt if it needs to be replaced.
There's the hydraulic "automatic" tensioners, which you remove the dustcaps on and pull back with an allen wrench to remove the belts, and there's also some traditional "bolt" tensioners. (the one for the big belt is on the alternator IFRC, and the one for the AC is right in the middle of the AC and the drive).
Once you take off the old belts, you have to loosen the bolts on the mechanical tensioners, and crank them back a bit while tightening them up.

[Gofast]

my car does this too but only on some mornings ... not all the time and it's only for the first 2 mins or so. the belts seem out of the question in my case though, since they were replaced less than 5k miles ago.

any other ideas on what might be causing this?

It could still be your belts, if the tensioners are loose.
It might also be the alternator, but that's more of a metallic "squeal" sound. Sounds like someone goosing a bird, if that helps.