Car knocking 06 elantra has knocking noise when accelerating both when in park and driving. In park if a/c in on you hear the knocking noise coming from engine. You also hear it when in reverse. What are the potential problems.

SOURCE: Knocking While Accelerating

Hi guardian.326 I need some more info try putting the vehicle in drive step on the brake and accelerator at the same time and see if knocks then. If so first check the timing on your vehicle,hope this helps,good luck

SOURCE: 1996 pontiac transport Knocks in park but not in drive

This is a damaged torque converter and you may have a blown shift solenoid as well. check the fluid level. i suspect major torque converter damage.

SOURCE: engine or transmission knock / rattle upon

I had the same problem on my 2006 Lucerne and it was the engine mount located on the front of the vehicle behind the radiator.