l GOT A NISSAN VANETTE VAN AND JUST HAD A SERVICE DONE ON IT AND A DAY LATER A CLUNKING NOISE APPEARED,LIKE METAL TO METAL WHAT COULD IT BE?VERY NOISY WHEN STARTING BUT DOESNT GO AWAY
NEW CAMBELT ALSO FITTED

Probable cause starter pinion gear warped or misaligned

Take it back to the garge where u had the service done & tell them. It may be something they have forgotten to tighten up. It happened to me recently, when my mechanic forgot to tighten the wishbone properly. You dont say if it makes the noise on starting or when u r actually driving. It could be one of several things. Can u pinpoint a direction where the noise is coming from?
Some things it could be; Brakes seized on. (brake cylinder may be broken or discs/drums may be worn or damaged) Drive shaft damaged, steering gaitor or Cv joint or gears. Whatever it is, u need to get it looked at soon as it could be dangerous. If u paid to have a full service, then the garage have not done their job properly, if it is one of the above. You have rights in consumer law to get the job done properly. If they haven't, u can report the garage to trading standards.