Engine Light

[98Silverado4Ever]

98 Silverado Shortbed Z-71 5.7 V8

 

Took my truck to one of those auto parts stores and hooked it up to a computer. Computer showed that my truck had a vacuum leak. I looked on the motor for any leaks of any kind and could not find any. Any suggestions of where it might be coming from? I'm sure I'm not looking in an obvious place.

[bronyaur]

Take a spray can of carburator cleaner, such as Chemtool, and spray it around vacuum fittings and hoses with the engine running. If the engine RPMs increase, you've found the leak. Check all connections.

[radiator]

If you have access to a fogging machine you could find it that way. I had thae same problem on my truck so i just replace all vacuum lines anyways. a roll of hose is cheap and it solved the problem.

[rodram]

You do have a Vortec engine so you are going to want to know if the vacuum leak is related to a failing Intake Manifold Gasket ... common problem on many GM V-6 and V-8's and particularly on this engine...