2002 Volvo V70 2.4T shudder at idle

After swapping a motor in my 2002 Volvo 2.4T I got a shudder at idle which starts after the car idles for about 2-3 minutes. The RPMs drop from 1000 to about 800 and the shudder begins.
So far I replaced the throttle body, MAP sensor, fuel filter, spark plugs, air temp sensor, turbo pressure sensor, cam sensor, crank sensor, cleaned and tested VVT solenoid, cleaned MAF, checked all vacuum lines. Checked the compression - around 135 psi on all cylinders.
The check engine light is not on and there are no codes.
I found 3 of the 5 ignition coils have hairline cracks on them. Rotating the coils around and replacing with a new coil made no difference but I do have 3 new coils on order just in case.

[@JoeSibCars]

It's a flywheel that's why you have a Shudder at idle so you need to replace your flywheel and that should solve the problem I hope this helps take care

[@dinosaurus1732]

so what was the cause in the end? did you find out what was the root of the problem?

[@2121hans]

have you slowed the problem :) ?

[@alfredocalpito9439]

clean the throttle body.