Hi cholula...I have a 54 plate,66000 on clock.Had lost power at top end,took it to nissan they told me i had a streched chain as the tensioner was out 6mls.Quote...£2500..took it to a friend he agreed,still in disbelief i took it to Infiniti Glasgow and they confimed this after checking various other possibilities.Got the job done for just under £1000.