i have a 2004 Golf first off

i started it up today and it stalled 5 minutes later while ideling

Then when i was driving down the highway i noticed a strange sound, like a tat tat tat

i popped the hood started it, sounded fine, reved it and then it started making the tat tat noise

The oil level is fine, engine isnt over heating

im thinking could it be the sprak plugs need to be changed ?

or what else could it be ?