2001 santa fe v6 AWD internal engine rattle

just developed a rattle, sounds like its internal on passenger side, not lifter clatter. It does it at idle and speeds up as RPMs climb. There are no codes. Milage is 129,000. Only had it 18 months, used.

I have looked at all threads in here and most are extremely minor issues and found nothing remotely simular.

Is there anyone who knows what this might be?

If it's around the passenger side of the engine, it could be something the serpentine belt drives, or the belt tensioner. If not that, it could be a problem under the timing belt cover, in which case it would be a good idea to have a shop look at the issue.

Are you sure it isn't a heat shield around the exhaust system somewhere?

you were right it was the belt tensioner. Dealer found it quickly with stethascope, replaced in 2.5 hours $198. Thank you!