Diesel engine hunting

[sponix]

Vehicle: Berlingo with 1.9 diesel engine
Problem: at between 1900-2000 revs the engine tends to start 'hunting'.
If you are accelerating or decelerating the problem doesn't occur; it only occurs when you are trying to maintain a steady speed.
All other rev speeds it's OK.
Any suggestions?

[sponix]

Update:
If I have the car stationary and rev the engine to 2000 rpm with the clutch down then the engine is perfectly smooth.
That's led me to think that maybe the problem isn't with the engine at all...maybe it's play in the drivetrain or a characteristic of the suspension causing the power to feel 'bouncy' at 2000 rpm?
(TBH, I'm not entirely sure whether all berlingos drive like this!)
Can anyone tell me if their diesel Berlingo behaves similarly? If not, anyone any ideas as to the cause/cure?

[AndersDK]

I have to say this is a common problem for PSA cars with the XU engine range.
Have your engine rubber mounts checked especially the lower one and RHS (car's) rubber mount.

[sponix]

I'd started to wonder the same thing..
Would the engine mounts be split/damaged or would they show no visible sign of damage? (If I can I'd like to ascertain which mount is at fault without having to replace the whole lot.)
On the drivers side at the top of the engine is a mount that has two rubber "buffer" type things placed front and back, presumably to limit the amount of rocking the engine can do. At the moment there are gaps between these buffers and the engine bracket itself. Should the buffers be touching the bracket or are the gaps there for a reason?

[bikeboyz]

have you checked all the fuel pipes from around the fuel filter + pump and tight and air free? small amounts of air can cause these symptoms too.

[Simon Canfer]

I had similar symptoms on my last ZX TD, they disappeared after I was forced to chang the driveshafts. (AFAIK Berlingo = ZX, mechanically speaking)
Simon