I was given a 03 Durango SLT with the 5.9. It has 199980 miles and I drive it fairly regular. So far I have replaced the following. Plugs, plug wires, cap and button, AC compressor, idler pulley and tensioner, front heater core, both front wheel bearings, all new rotors and pads, flushed the radiator and recently replaced the fuel pump. When I first replaced the plugs, wires and cap I also added seafoam to the gas and oil as well as a can of seafoam throttle body cleaner. It ran great for a few hours then started missing, running ruff or not running if the gas pedal wasn't engaged. This eventually cleared up and it ran ok till the fuel pump went out. After the tune up it has never seemed to idle right upon cold start or if it's been sitting for awhile. Sometimes after sitting upon strat up I get a rich smelling white puff of smoke from the exhaust. Also when I replaced the plugs, the old ones had alot of what looked like corrosion to me.
I would like to get it as mechanically sound as I can on my budget right now. Is it worth the money? I seem to find mixed opinions about the 5.9. Is the 5.9 a good motor? I also bought a 03 Durango specific service manual, DN 81-37003058. Amy help on what I need to start focusing would be greatly appreciated short of a engine rebuild. I actually like the car and would like to rebuild the motor in the future. For now I want to do what I can to make to the engine rebuild.
Started using Castrol 10w30 high milage oil with Mopar filter. Put in Platinum Champion plugs. However I read somewhere that Platinum plugs shouldn't be used in my 5.9. Is this accurate?
I feel like my post is information overload and would like to thank everyone in advance for taking time to read and respond.