Juddering

When you say juddering do you mean it is hesitating or the vehicle is shaking back and forth? A judder is commonly used is many different forms so just let me know a little more detail about what the vehicle is doing and when it does it. Do you have to be moving or does it sit still and you are revving the engine?

It is hard to say whether you should still use the vehicle but if there is no check engine light flashing and the vehicle is driving okay, then I would say it is. However, if this judder is a shaking of the vehicle when the vehicle is in motion then I would suggest not using it too much until this is corrected.

Let me know this detail and we can go from there. Thanks

Do I understand you correctly that the engine will do this when starting and revving it? Meaning does it do it in park when just sitting still?

If so, I suspect you have a misfire or vacuum leak? Is the check engine light on or flashing? Have you checked for codes?

Here are a number of guides that will help with this:

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

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

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Does this seem to fit what you are seeing?