I just bought an 84 se 2m4 and when it gets warm and I let up on the gas while driving I hear a loud whistle. I have replaced the gasket between the throttle body and intake but it didn;t help. Any help would be appreciated.

I've had my share of whistle noises coming from the engine compartment... ;)

It really could be anything, from the air-intake to a leaking manifold or even the alternator belt (which can make some pretty darn weird noises!). All the noises I've had so far seemed to disappear over time so I've learned to ignore them.

I know that really doesn't help you so perhaps there is someone else with any ideas?

This noise could be a vacume hose leak.

If indeed it is a vacuum leak, how can someone diagnose it? I've heard of several methods, like sticking a hose in your ear and poking the other end of the hose around the engine compartment, or spraying WD-40 or ether around the engine compartment until the motor speeds up.

Neither of these seems very reliable. Is there a better way? Maybe something using a vacuum gauge? There are so many vacuum hoses and tubes, it's hard to tell where to start looking for a leak.

could be any of the above..... check the EGR mounts to. they have a nasty habit of working lose. If they are lose, replace the EGR gasket.

checking for vac leaks is a pain. no matter what way you use, it's trial and error. basically if the tube fit is lose, it's probly leaking.

read down thru the hot start thread..... we cover allot of things to check for vacuum.