Hello,

Recently bought a 1999 Dodge Durango 5.9l with 170k miles on it. This one is to replace another of the same year when its transmission started going bad. I've noticed that while going up hills while in the 36 - 40mph range, right before the trans upshifts, I'll get jerks, back and forth motions consistent with momentary power loss. After the trans shifts, no more jerks. Alternatively, if I turn off overdrive, there are jerks but less in number. I'm thinking missfire, because at idle after a long drive I can feel the engine vibrate hard for an instant every so often. I'll add that the trans fluid is still red in color, at appropriate level, and it performs well considering its age, so I don't think it is the cause. Thoughts?

 

New plugs, wires, dist cap and rotor.

 

My 99 5.2 does this also. I tuned it up fully and not as bad but still feel it. I wondered could it be a fuel pressure issue. Is that something I should check? Sorry to thread jack Amblin.

 

for both of you this might be a weakening fuel pump

 

Fuel pump... under WOT ill occasionally hear some knocking coming from the rear end that accompanies the intermittent loss of power, too far back to be the transmission. Perhaps it's the fuel pump?

 

I also have an issue (Duralude) where every now and then it will fall on its butt after a start when I start driving. After I release the throttle and return it its fine. I'm gonna check the fuel pressure this weekend.