A bit rattly on start up
 

Hi, had my XTX from new on '07. It's been great apart from just recently. Nothing too major, but in the recent really cold weather it's been rattly when starting up. It's only done 18,000 miles so the cam chain seems unlikely. It's just had a service so the valves are good. Do the tensioners give problems or just need to get up to pressure to work properly? The rattle goes after a minute or two.
Any help/ opinions welcome.
Thanks

What grade/viscosity oil are you running?

Not totally sure what the garage put in, but had the rattle before the service and I had the recommended grade synthetic.