So in the last two days heres what I did to my car:

-Seafoam through the intake (vacuum line)
-new AC Delco Spark Plugs
-new AC Delco O2 sensor
-Changed oil pan gasket and oil level sender
-put fresh Quaker State and delco filter into her
-Changed to 180* T-Stat.

She runs GREAT save for a chirping sound that now sounds like it is coming from under the engine. I tried to listen to all the pulleys and it doesnt SOUND like it is any of the ones i could hear (Alt, Tensioner, Power steering). The AC pump is less than a month old so i doubt that is it...

You cant really hear it under the hood, but its pretty loud under the car, seems mostly from the passenger side. It sounds like a buncha birds on steroids and chirp speed is linked to engine speed. Could it be the water pump? did i shake up the crap in there too much and now its dying?

Does this sound like anything familiar and would it be related to something I might have screwed up over the set of maintenance i did?

Check your vacuum hoses and did you swap a pcv as well? If so..double check the o rings on it.

Checked the vacuum hoses, they're good. And i didnt touch the PCV, and wouldnt that be more of a whistle?

One thing i noticed: Its not constant.

*note: my drive to work is only 2 minutes*
Drove to work, it chirped the whole way.
Drove home, it was quiet.
Drove back to work, chirped again.
Drove home again, was quiet.

I guess it isnt anything major, but it doesnt sound good when it happens.

Could you have gotten oil or coolant on the harmonic balancer, or belt, that may be causing it to squeak?

Its possible, but i dont think so. Ill have to look into it after i drive it more, but nothing really was spilt over there.

How did you refill coolant when you changed out the thermostat? Did you fill the engine at the thermostat opening as described in this procedure: http://www.bonnevilleclub.com/forum/...=article&k=100 I have not heard of air pockets causing noise, but since the noise is coming from the water pump, maybe it is possible, if the air pocket is large enough to reach the pump. (?)

More likely you have a belt chirping on a pulley or a bearing going bad as others suggest. Maybe you will need to replace the water pump.

My Olds 88 had similar chirp per your description. You mentioned a new AC pump, I assume that you mean AC Compressor.

My squeak ended up being the air gap was too small in the AC clutch. The squeak was caused by the AC clutch dragging when the AC was off because there was not enough air gap in the clutch. (.010"-.015" gap IIRC).

Test 1. With engine idling and AC off, look at the AC clutch. The finger end of the clutch should not rotate ANY. If the clutch is dragging, (due to insufficient air gap), it may be squeak source.

Test 2. With engine idling and AC on, does it squeak? If so, it isn't the air gap.

If it is the air gap, you can purchase a specialty puller tool to adjust it. (~$20)

I know your compressor is new, but it is possible the clutch was not properly adjusted.

Good luck. I changed about every belt driven component on my Delta 88 until I fixed this one.