Maybe once a week the yukon with 240k miles on it will drop in RPM's as it sits in the driveway warming up. Does something need to be cleaned? I know air filter and intake are both clean. Maybe a sensor you all can point me towards?
2003 Yukon XL RPM drop at Idle
- Thread starter RAWVORTEC
- Start date
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Possibly dirty MAF.
Check alternator output voltage on the "fied terminal" lug. Turn off ALL electrical accessories such as radio, a/c, lights, etc...
Voltage should be above 13v with the engine running.
In theory, the truck runs on a 12 volt system, but in reality, 12 volts wont keep the engine running effectively. Turn on a couple electrical accessories and voltage could drop as much as one volt.
Another thing you could do is drive to an auto parts store and have them test the alternator with thier machine. Have them perform a 'load' test.
Just because an alternator can keep an engine running, doesn't mean that the alternator is good. Maybe it is beginning to go bad.
Voltage should be above 13v with the engine running.
In theory, the truck runs on a 12 volt system, but in reality, 12 volts wont keep the engine running effectively. Turn on a couple electrical accessories and voltage could drop as much as one volt.
Another thing you could do is drive to an auto parts store and have them test the alternator with thier machine. Have them perform a 'load' test.
Just because an alternator can keep an engine running, doesn't mean that the alternator is good. Maybe it is beginning to go bad.
