we have a vibration

Hello,

There could be few reasons of why engine is vibrating. Typically, when the engine runs rough (misfire) it will vibrate. It can also vibrate when there is a vacuum leak.
Other possibility is having worn engine mounts.

Please let me know little bit more information of what else you might be experiencing. Do you have issues with acceleration? Does it hesitate?

Here are some helpful guides on typical vibration or engine running rough causes:

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

Please let me know what other issues you might be having along with the vibration.
Thank you.