First off, I just made an account here so you could say I'm new to the forum, although I've been reading through the many pages here for quite some time.
Here's the story....(with a bit of background info)
First off I'm a 16 year old guy so please bear with me here. Just a couple of days ago I (as in "myself") purchased my (as in it's truly "mine") first car, a '98 Grand Prix GT with 156k. It's white, 2dr model, with tan leather, sliding sunroof, HUD, power seats, mirrors and locks, dual climate control, and Pontiac's version of "chrome" rims. I don't think I did too bad for $2200, but we all have our opinions .
Anyways, when I was looking at the car I was told upfront it had a vacuum leak and (obviously) idled rough, but ran fine down the road when drawing in more air (which it does run good down the road). When I purchased it it did have a ever so slight noise coming from the engine. I attributed this to the vacuum leak issue and thought nothing more of it. After pulling in the driveway, however, I got looking around and found that someone had routed the belt incorrectly causing it to rub on the oil filter base. No problem, the belt had survived the almost 2 hour interstate drive home (in which I was getting 31-33MPG according to the monitor *big grin*) and didn't have any major signs of damage, nor did the oil filter base. Next on my list of things was to fix the vacuum leak (it does have a few other problems, some of which I might be asking about later, but that's beside the point).
I figured out that someone had drilled (yes, I said drilled) a hole into the extension for the oil fill. After a bit of duct tape I got the vacuum leak temporarily fixed, but managed to get a God-awful screeching/squealing sound from near the belt-side of the engine.
I've eliminated the possibility of it being any pulleys ceasing up (took the belt off (again) to test that) and have narrowed it down to something vacuum related (which I realize doesn't mean much).
I've read up on some people having a similar problem with the PCV valve, but I've taken the valve out and tried numerous things while plugging/un-plugging the hole in the extension and regulating air flow with my finger acting as the PCV valve. Between myself, my mechanic dad, and my also-mechanic uncle, we think there is another vacuum leak somewhere between the oil fill extension and the PCV valve.
All 3 of us are stumped except for thinking it could be something manifold related (as it does have the plastic manifold *sigh*).
So, if any one here could be kind enough to enlighten me with any possible ideas as to why and where this noise is coming from I would greatly appreciate it (and so would my neighbors ears)!!
Sorry for having such along post, but it's frustrating trying to fix one problem and meanwhile creating a more complex, and much, much noisier one.