Vacuum leaks can be located with spray carburetor cleaner or a can of WD-40. If the area is obstructed by linkage or hoses, use an extension nozzle to pinpoint the area of the vacuum leak. If the engine speeds up when an area is sprayed, you are close to finding the leak.

Make vacuum leaks hiss-tory

Insufficient intake manifold vacuum can be deadly to an internal-combustion engine. It will reduce engine efficiency, causing a loss of power and fuel economy and rough operation, especially at idle. Prolonged vacuum leaks can eventually cause serious engine damage. Here's how to fix it.