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Q: Erratic RPMs, 1995 BMW 318is

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Lately, the RPMs have been fluctuating and I'm not sure why. I had some worn hoses replaced. The throttle body has been cleaned along with the idle control valve. Still, there RPMs keep increasing and decreasing erratically. What might be the cause?

Hello there, there are a few possible causes for your 1995 BMW 318is to have a fluctuation in the RPM’s. The most common are a vacuum leak, oxygen sensor, throttle sensor, exhaust leak, or the fuel pump. I recommend have each of these items checked in order to scope out the cause of the erratic RPMs. If you need help with this, a certified technician from YourMechanic can come to your car’s location to inspect the idle and let you know what should be done.

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