Audi a4 Making grinding noise and i cannt figure it out!

[diddy92]

Hey guys so my A4 recently starting making a grinding noise after i used a fuel additive for cleaning the Catalytic Converter. The good news is the Cat is not clogged and is now open enough to allow my car to exhaust and not cause back pressure.

It happens when i am at a low speed and accelerating, It happens when i am slow on the accelerator and also when im heavy on the accelerator.

I have spent many hours trying to google and watch you tube videos to find a similar video to my issue and i have had no luck.
My best way to replicate it was when i pull the E brake and press the brake down fully with the car in Drive and raise the RPMS a little.

[old guy]

Its very hard for me to tell from the video but what you are describing is similar to the noise that my Geba water pump made when the bearing was going out.

[ShogunR32]

I am dealing with this exact issue with my 04 1.8T Auto. It has been making this noise since I bought the car 6 months ago. It is not the water pump, because I changed it out for a new one, It is not the CCT because I swapped in a new head. I also though it might be something rattling in the front so I bought a new FMIC, still no fix to this rattle noise. I am starting to think it is related to the transmission somehow and not the engine.