Vibration at a certain RPM?

I have not heard of anything typical on this, but can I ask if you replaced the engine torque mount (strap), Also, I have seen the CV axle cause this problem, the cups will wear causing the CV balls to skip and jump under power which sounds like what is happening. You won't be able to tell by removing the axles without a complete tear down of the axles to check the cups. At 140,000 they should be worn out, FYI.

Seat Leon 2.0 TDI vibration.

Hello, my Seat Leon 2.0 TDI (CR) makes a vibration at 2,000 RPMs and at 4,000 RPMs the whole car vibrates like it’s a v8 truck.
It only makes when the car is loaded, at any speed when reaches 1,900-2,000 RPMs a vibration like sound comes from the engine bay, if you accelerate past that range, the sound stops.
Firstly, I thought it could be an engine buffer, so we changed all three (left, middle, right) to new ones. The vibration is the same.
(Full revision was done oil and filters and timing belt has been changed)
The next thing was the double mass flywheel since it has been running with the original clutch, got changed but the vibration is still the same. Not even the REV range where the vibration had changed, nothing.
I’m worried about that the crankshaft could be the problem.
Does anyone ever meet a problem like this?

Hello,

The two most common causes for vibration you have addressed already, engine/transmission mountings and DMF.

Another area to consider would be the CV joints, especially the inner ones.
At times these can become dry or worn and can cause a vibration under acceleration.

A good read:
https://www.2carpros.com/articles/symptoms-of-a-bad-cv-axle-joint
and
https://www.2carpros.com/articles/how-a-cv-joint-works

Cheers, Boris

Thanks for your answer!
All engine mounts were changed, because that was my thought as well, the vibration still the same, next thing was the DMF which I was sure that will be, but the vibration stays the same.
CV joints are excluded because the vibration comes in only at 1900-2000RPM and 4000RPM, regardless the speed (in 1st gear it’s around 10-15km’h and still does the vibration). CV axels vibrate at any RPM and higher speeds.
The problem comes from somewhere else. My last guess is the crankshaft

Hello

Can you reproduce the vibration when stationary?
If not then this will eliminate crankshaft issues as the engine would also vibrate when stationary.

Have you inspected the exhaust mountings? Also check the exhaust routing, make sure its is not to close to anything. Check that the exhaust heat shields are no broken, securely fitted

Cheers, Boris