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Sporadic RPM increase

I have a 2000 Volkswagen Jetta. For the past 4 months the car sporadically increases the RMPs. It could happen while driving or when stationary. It usually revs the engine to about 3,000. Normally, turning off the car when stationary fixes the problem. However, if the engine is not turned off, the engine will decrease its RMPs after about 5-10 seconds. The frequency of this problem has been increasing. What is the problem with this car?

The first thing that I would check is the Mass Airflow Sensor (MAF). It may need cleaning, or it may need to be replaced.

Another possibility is a vacuum leak, but in the case of a vacuum leak, the RPMs would fluctuate constantly, rather than sporadically.

Check engine light on? Codes?

Does the engine actually rev up to 3000 or does the tach malfunction?

The check engine light also sporadically comes on but it doesn’t always correlate with the engine revving up.

Have the fault codes downloaded and post them here. Many parts stores will perform this service for free.

Great! Thank you. I will do that and get back to you.