My still new to me 3.9 2003 Dakota with 65,000 miles. Dealer that did fluid services and thought rotor and wires looked original, so since with that mileage plugs and wires were due, I did them. Here are the pictures, I think they may have been original. Rest of the truck had not been over maintained to say the least. Still had rear Goodyear tires with 2003 DOT codes on it. Plug gap measured about double.


Mike

 

Cap looks good plugs just a bit worn is all wide gap

 

I agree, cap look a little iffy, I dont think they were original, electrode would be 3/4 melted off and thered be no center post outside the insulator.

 

Now that I look closer that cap is worn out plugs could be re gaped and installed they are not original parts.


You should get a copper terminal cap if possible the aluminum ones suck they oxidize too much as you can see.

 

Forgot to say - that is what I did, Copper Cap with new Rotor, new Autolite Wires and Autolite single Platinum Plugs. I know you don't have to use the Platinum plugs, but hopefully just a little better wear out of them for only a little more money.


Did idle better after the tune up, but replacing the IAC and a little bit of cleaning on the throttle body helped the most, other than my other post of losing the plastic spray extension in the intake.


But one step at a time, at least making progress on getting the truck running evenly. It does seem to run well now, fairly smooth power and despite the automatic transmission shifts evenly also. Sometimes when I want it to downshift maybe to second from third, it's not responsive, but after a fluid change at the dealer and reading this forum seems it's just the way these transmissions work. For buying an older truck at least it all runs and stops when I want it to. Oh yes with only 65,000 miles that's what I was hoping for. A good running truck.


Mike

 

You may start getting misfire CEL's and/or lose fuel mileage with the magnum pushrod motor. YMMV, but typically our motors hate the platinums.

 

I found a simple solution for cleaning oxide off the cap terminals, used to do this on my old Jeep cherokeee, before the frame rotted off. I would use my drill and a 2 in wire wheel. the wire wheel fit between the posts and would clean off all the oxide. The posts would look like new after a few presses of the drill trigger. Never had to replace the cap.

 

I used to do something like that I used a fingernail file on each post but now I just buy a new cap and rotor every few years.


Reminds me I need to pull my cap and check it its due.