So I have an 03 Durango SXT. It has a 4.7 in it and it has an obnoxious knocking noise that it does most of the time. I have tried putting fuel injector cleaners and and lucas oil treatment to try and fix it. Nothing has worked and I was wondering if anyone has any suggestions for me.

 

Welcome to DF

You need to isolate the problem. Remove the fan belt, just to make sure its not belt driven. Next is the knocking upper end or lower end of the engine. I have seen timing chain guides cause a knocking type sound.

 

You could also try doing a power balance test. Start the truck and remove each injector wire one at a time to see if the knocking stops/changes if it does you at least know which cylinder the problem is in.

My AC compressor makes a little bit of knocking when it first turns on so turn your ac off and see if it goes away.