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Ask GM Master Tech 01 Your Own Question
GM Master Tech 01
GM Master Tech 01, GM Master Technician
Category: Chevy
Satisfied Customers: 337
Experience:  GM certified master technician 10 years experience
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2000 chevy silverado 4.8ltr v8. Rough idle and hesitation ...

Customer Question

2000 chevy silverado 4.8ltr v8. Rough idle and hesitation upon acceleration from stop. This only occurs after 30 minutes of driving. It runs great and idles smoothly for 20 to 30 minutes then begins to act up. It has 100k miles. I put in new plugs and wires,map sensor,low speed idle control valve, air filter, and have run several bottles of injector cleaner through it. On two occasions I got an engine light that coded out as random multiple cylinder misfires. The engine light never stayed on for more than a few hours. What should I try next?
Submitted: 9 years ago.
Category: Chevy
Expert:  GM Master Tech 01 replied 9 years ago.
You need to check the manifold gaskets for an air leak, Spray brake clean along the bottom of the plenum at the head at idle and listen for the engine idle to change.