very loud high pitched noise

[Triplecat2002]

I have a 2003 GT Turbo that just turned 60K. I am very good about maintenance on the car as I want it to last a long time. Yesterday I was driving into work - about 5 miles highway, about 5 miles city streets - and when I was parking and turned off the radio I noticed a very loud high pitched noise coming from the front of the car. I rolled the window down and wow was it loud. It was definitely not a belt sound. So I turned the car off. When I went out for lunch it was still doing the sound. When I am at a light, the sound is there. When I give it gas, it goes away for a while and then comes back when I am going 15 to 20 miles. Once above 20 miles, it stays. Last night when I pulled out onto the road, the check engine light came on. I took it easy on the way home, not going above 55. I am worried it is the turbo. I just had the 60K maintenance done two weeks ago - oil changed, new spark plugs, pcv, trans flush, new batt terminal and brake fluid. I bought the car when it was 3 years old at 24K. I am wondering what is wrong and if it is the turbo. I am not driving it today.
Thanks for any advice.

[Jabouty]

The only real way to diagnose noise issues is to first locate the area of the engine compartment that it's located in.

Start the engine and then stick your ear in the engine compartment and listen to where the sound is coming from. Rev the engine a few times to get a good feel for where it's at, and if push comes to shove you can use a long screwdriver with the handle against your ear as a kind of mechanic's stethoscope and poke around the block abit to see if it's there. Metal on metal squeal as you describe will usually be an accessory, a/c, alternator, power steering pump, etc, or even the turbo as you suggest. But first locate the sound, front or back of engine, driver / passenger, upper lower etc and go from there.

[quicksilverdon]

Agree w/Jabouty. Also, shut off A/C to rule that out.

[Triplecat2002]

Thanks for the responses. It was cool that morning so the AC was off so I had been able to eliminate that at least. Looks like it is the exhaust manifold gasket. You would not believe how loud the noise is. I am just relieved that it is not the turbo!

[Triplecat2002]

Just to correct... According to the receipt, it was the Intake Manifold gasket, 4884195-AA and 4884192-AA.

[quicksilverdon]

I've know exhaust gaskets to be noisy, but intake ?
Live and learn....

[Triplecat2002]

I was thinking that over the phone they had told me Exhaust manifold but later when l looked back at the receipt, the problem description said Intake. On the receipt where the parts are spelled out, it just says gasket and some part number and there were two of them.

Exhaust made more sense to me than Intake. The sound did go away when they finished the work.