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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?

A: Hello there, there are a few possible 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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