Answer:
The easiest way is to buy a can of throttle body cleaner. Start spraying it around the edges where the intake manifold seals. You may need to use the little tube supplied with it to get a more precise spray pattern. Any change in engine RPM or idle characteristics would indicate a vacuum leak. If you are referring to a coolant leak, you should be able to see the coolant....either pooling up or dripping. Those engines within a few years before and after yours are known for weak intake manifold gaskets from the factory.