C5 X3 hesitates on acceleration

[Peter.N.]

I have just bought my 4th 2.0 Hdi C5 estate, very nice car, very cheap but it hesitates on accelerating, don't notice it all the time but often it frightens you, you think its going to stop, it doesn't though and as soon as the revs come up a bit it drives perfectly. On the motorway drives perfectly. I have changed to fuel filter and checked the fuel lines for bubbles but it all looks fine.

Any suggestions? Thanks

Peter