Q: Engine knocking at higher speeds

Hello. A knocking sound during heavy acceleration could potentially be a sign of a serious issue, depending on where it is coming from. A knock from the engine can occur if it runs low on oil, and could quickly lead to serious engine damage if it runs too low. If the oil change is past due I would check the oil to make sure that it is not low and possibly causing your issues, and change it as soon as you can. If it is low, top it off to prevent the possibility of any oil related issues. Similar symptoms, including stalling, can also be caused by issues with the vehicle’s engine management system, if misfires or ignition knock occur. Misfires and knock can occur if there is issues with the ignition fuel or engine management systems. Ignition knock can also commonly be caused by low quality fuel, or if the incorrect fuel grade is used. Both of these symptoms will usually come accompanied with a check engine light. I would recommend having a professional technician, such as one from YourMechanic, come to your location to diagnose what may be causing your engine noises, and what may have caused your stalling.