Hi just got my nissan tino last week its a 2002 model ,as days go by you start to notice things about the car you didnt notice when i first got it... hope this is normal just noticed when you start the car first thing in the morning you can hear a very very slight knocking noise just for a 5- 10 sec period then it goes away is this normal, its a 1.8 twin cam very slight knocking i may say any help would be great thx