2002 GMC C1500

2002 GMC C1500
160,000 MILES • V8 • 4WD • AUTOMATIC
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BMGIBSON5
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I have a 2002 gmc 1500 four wheel drive with 160000 miles. The problem that i am having is that in the morning i am having problems with the truck idling. It will idle up to about 3500 rpm for about 5 to 15 seconds and then if it stays running it will bounce between 100 and 500 rpm. Most of the time it just dies. when it does stay running it sounds terrible. it usually does this for about five minutes every day as long as the weather is colder than 50 degrees ferinhiett. could it be the O2 sensor
Dec 10, 2009 at 12:52 PM
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42DEGREES
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Is your check engine light on? What are the codes?

An idle that high sounds like a vacuum leak, see if you can change the way its running while spraying carb cleaner around the base of the intake manifold.

If you have vacuum brakes make sure the vacuum hose to the booster is OK and pull the hose out of the booster with the enigne off, you should hear some "suction" or "air noise" as you pop the fitting out.

Does it ever clear up or does the vehicle run poorly at all times?

There is an updated intake manifold gasket for your engine if you determine its a vacuum leak there. This is assuming you have a 4.8,5.3 or 6.0L

- RL
Dec 10, 2009 at 1:21 PM
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