i have no idea about the intake gasket, but my car started making a loud high pitched whiningalmost screaming noise. it only happend at idle when i brought the rpms up a lil like to 2000 it would go away. i brought it to the dealership and they said it was the clutch. lukily i was still under warranty so they replaced it for free. this happend to me at like only 9000 miles on the car but i geuss i just drive my cara lil harder than most (fourth generation race car driver). so if the intake gasket dosnt do it and it is still making the noise try the clutch.
peace

 

Intake Manifold gasket = 1 hour at the most. EXTREMELY easy. My buddies girl friend (who does not normally wrench on cars) did his for him (why he didn't do it himself I couldn't tell ya). Just make sure you thoroughly clean the old gasket material (if there is any) off of the head and the manifold before you slap a new one in...

 

It was pretty easy. The actual time to change the gasket took me about 1 1/2 hours, half an hour of that was trying desperately to get the old gasket off of the face. When the bolts were installed a bit of Loctite must have fallen onto the gasket as I had a hell of a time getting some of it off. Of course I didn't want to start gouging into the aluminum face, so I took my time and made sure that it was done right. I also figured that while I was under the car I might as well tighten all of the hoses and make sure everything is good. I took the car for a run, and I'm thinking that the gasket must have been leaking for some time. I can't remember the last time it ran as good as it is now. 2 1/2 hours total time including clean up and test drive and I just saved myself $395. It's almost criminal how much they try to rape people.