2005 DGC. When accelerating from a standstill I hear a groaning noise in the front end. Noise stops if I let off the gas. Noise dosn't happen from a roll. Noise doesn't happen if I accelerate gently from a standstill. Makes no difference if the wheels are pointed straight or turning.

Has anyone experienced this or have an idea what to look for?

 

sounds like vacuum leak, belt-slip, or belt component somewhere, or you've got a valve or main issue and you're about to get reamed by some shop..

 

No, none of the above. Definitely not a vacuum or belt noise. Valve or main issue? How is that going to make a groaning noise?

Since the groaning noise doesn't happen when punching it from a roll, I have to assume it has to do with shifting of the engine under initial (hard) acceleration, but can't quite figure what. Bad engine mounts would aggravate engine shifting, but engine mounts don't make groaning noises.

Hoping someone had this issue and found the cause.

 

PSI changes with RPM in most parts of the engine as does mechanical vibration.

Logically it could only be caused by the pressure of a hard acceleration from low RPM(vaccum or PSI on power steering and water pump) or tranny or cv from from force or weight shift. Any electric motors would be obvious because locations.