Q: Rough engine noise on startup, idle and low rpms

asked by on October 17, 2016

I had a low oil level without any warning lights that I didn't know about, I drove the car at around 70MPH on a mountain road for 20 minutes and when I parked the car was all shaking on low RPM when idling. I drove the car again and when my speed goes up the engine keeps the noise but I can't feel the shake. The noise is best described as a stutter. I haven't noticed any performance issues.

My car has 1211673 miles.
My car has an automatic transmission.

Hi and thank you for contacting YourMechanic. What seems to have happened is that the oil level was too low causing the engine bearings to have less clearance on them, making the rods bounce around. This is the stutter feeling that is occurring from the engine.

The engine should not be operated if the oil level is lower than 3/4 on the dipstick markings. I recommend topping off the oil and running the engine to listen for any more stuttering noises. If the noise goes away, then the engine was just too low on oil. If the noise continues, then there may have been engine damage due to running at highway speeds with low oil.

If you need further assistance in troubleshooting your engine vibration, then seek out a professional, such as one from YourMechanic, to help you determine why your car is making this noise and how to repair it.

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