00 engine nock

my dad here has a 00 durango w/ the 5.9 in it and when ever you get into the gas there is a sort of engine nock or ping? any ideas?

does it w/ 87 oct but not with 93

Have your dad to check the owner's manual to see what octane rating is recommended or required by your Durango.

I have a 00 Durango with a 5.9. It's a R/T model. The durango REQUIRES 91 octane. If you put anything less than that, your engine will ping, knock etc. Good thing in DFW, most places, especially at Costco/Sam's, their premium gas is not too expensive and their Octane rating is at 93.

I had the same problem with a 98 durango and lucky for me I had a warranty left on it. The problem is your manifold gasket, I think it was the intake. My local Dodge dealer service advisor actually diagnosed this over the phone and said it was a common failing in these rigs, so you may wish to call them to find out exactly which one it is. Repair that and you can run the lower octane fuel and pull hills without that annoying knocking/pinging sound.
Hope this helps.