help Shaking at idle (Sometimes Stalls) - Misfire all cylinders

[SuperFastYo]

Hello all,

   Hoping you can help me pinpoint the issue. My 2018 A4 started shaking at idle a bit ago, when pulling codes I had misfires on all cylinders. The car will drive just fine, doesn't feel like there's any loss of power. At idle when it starts to shake I can put it in park or neutral and rev it to 4k RPM and then the issue goes away for a little bit. 

   Because of this I started my google search to see if anyone could point me in the right direction before I start pulling apart and replacing stuff. Someone said if there's a vacuum or pressure when removing the oil cap it could be the Oil Separator, so I changed that out. Nothing changed.... I moved to the Coil Packs and Spark Plugs... Still no change. 

   I'm at a bit of a loss, I was thinking of doing the injectors, & since the intake manifold would be off clean up the carbon build up and replace the water pump (Ive gotten the code for it randomly a few times but it never stays). I really rather not spend all that money if there's a more common cause that could be the issue that I just haven't considered. Does anyone have any input on this?

Edited Wednesday at 04:13 PM by SuperFastYo

[Magnet]

Engine mountings?- for shaking. 
What make coil packs and plugs did you use? 

[Steve Q]

Could get the injectors tested for peace of mind. Could be the injector seals? 

Could ideally if cleaning the carbon build up. If you're replacing the water pump you may as well do the cambelt. 

[SuperFastYo]

Decided to full send Injectors & replace the water pump while im at it. Gonna clean everything up.... its all been taken apart and I'll be putting it back together with new parts in the morning...

 

https://imgur.com/a/zyAmBH2

[Steve Q]

 We're the injectors ok then? 

[SuperFastYo]

42 minutes ago, Steve Q said:

 We're the injectors ok then? 

Haven't installed them. Today I removed pretty much everything on the right side of the engine. Tomorrow im installing new water pump and injectors. Also cleaning throttle body... I'll report back.

[spartacus 68]

When replacing injectors (use a little ceramic grease on the body of the injector) and check if ‘o’ ring if one fitted needs replaced, plus the seating or sealing washer is new, use new stretch bolts and torque to specification, then tighten union nuts to fuel rail. If a new injector it needs coded to the car.