My 2006 x type jaguar diesel has started chugging at 30mph and various other speeds but stops after slught acceleration. It throws out black smoke on acceleration but still has all its power.

Any ideas please?

Hi Sandra, and welcome to the club.

One of my son's has a diesel X type 2.0 litre on an 06 plate.  I assume your's is the same model.

There can be several causes of Black smoke, but basically is is non burnt fuel.

This can be easily cured, as all that is wrong is the fuel system that needs cleaning.  First, put a useful additive in the fuel tank as it could be a faulty/clogged up EGR valve, [which is the Exhaust Gas Recirculation valve]  I use Millers Diesel Power Eco Max which will give you a clean 500 litres of fuel.  One dash in the fuel tank every fill up. I also use premium fuel, which is well worth  the higher price.

Let us know how you get on with that before having a look at other things such as the turbocharger.

I am fairly confident that it is the EGR valve, though.

Regards,

Peter.