loud rattle from engine td4

Hi all,
last week my alternator packed up and was replaced. As the old one died I heard a very loud engine rattle which came from low down in the engine on the near side. It only lasted a second and usually happened when accelerating from about 30mph and was accompanied by a puff of black smoke from the exhaust. The RAC guy who towed me home said it was probably caused by the engine management system being confused by the lack of power from the alternator.??
despite having a new alternator it is still happening. It only happens now and then and sounds like shells or big end. Apart from that the engine runs smoothly, starts first time with no warning lights showing.
The engine is a td4 which has done 94k 2005.
Any advice would be appreciated

Hi Pat, there are some here who like new members to introduce themselves before getting to the problem, some sort of British tradition I think.

However you do seem anxious to dispense with the formalities as the fault sounds as though it's distressing you.

I have not had a diesel hippo, but have had some diesel experience, and my first thought would be that an injector is sticking open occasionally, putting extra fuel in which causes a knock when it fires and spits out the black smoke. This knocking can cause considerable stress on the engine and should be investigated quickly.

Someone else's opinion might hold more weight.

Yes, it's simply good manners.

Also, searching is a good idea.

Have you considered this -

http://www.landyzone.co.uk/lz/f9/td4-crank-pully-clatter-66563.html