I hear a loud noise coming from the engine and the car won't go over 20 MPH.
With the speed limitation and the loud noise, I recommend not driving the vehicle until it has been diagnosed and repaired. It sounds like the vehicle is either in limp mode or a mechanical failure has stopped the vehicle from moving properly. A qualified technician, like one from YourMechanic, will be able to diagnose your acceleration issue and perform any repairs that are required.
Have a car question? Get free advice from our top-rated mechanics.
Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing