Hanzo

Hello Audi mates,

Previous Audi owner, having purchased a new Manual 6 speed Audi A4 Sline 2.0 TDI end of 2014.
Everything is marvelous about the car, no complaints whatsoever.
Until recently, I have been hearing a thumping noise or something rattling from the engine only when I am at neutral gear waiting for the red light to turn green. This also happens when I just start the car up in the morning, occasionally happens during the day, only at a very low speed or neutral gear.
The noise is very annoying, I brought the car to my mechanic who instantly found where it came from. Attached is the image of under the hood selected in red with the affected area.

Red selected part {top cover of filter to change after each oil change} Also this is a TDI engine {same thing really}


I assume that this is probably happening because one day when the oil change mechanic changed the filter, he must have misplaced the thin rubber piece placed between the top cover and the the base holding the filter (which has 2/3 screws, but they don't tighten the piece enough for it to stop the rattling noise due to the vibrations of the engine close by).
When the car engine is on and the hood is open, you could hear the constant vibrating THUMP THUMP THUMP, the sound is MULTIPLIED by X 1000 sitting inside the car. However, once you put hand pressure on the top filter cover, the noise is majorly reduced and sounds normal. One mechanic told me that this is an issue Audi have, suggesting I put some screwdrivers to force the cover to stick to the body holding the cover.

This means piercing certain spots, creating holes putting "non-conventional additions" to the engine.
I come to you Audi friends, hoping to receive a suggestion or advice on how to remove this very uncomfortable recurring noise.

Thank you,
- Hanzo

SMac770

Sounds like something is loose or misplaced. Unplug the MAF, unscrew the hose to the turbo, undo the six screws that hold the air filter cover to the air filter box, remove the cover. So does something look wrong? We can't look for you. Remove the air filter. Anything in the box that's loose? Pull the air box up and remove it. There's the rubber mount at the left end, is it ok? There's the tube at the bottom that has to feed into its hole correctly. Maybe they messed up one of the six screws and it's not seating well?

I'm not sure I'd advise running the engine without the airbox to see if the sound persists with all the relevant materials removed, but you might hook it up and just hold it in hand instead of mounting it back in place and see what happens.

whyjay91

Did you find the solution? I have something similar. Thank you!