running rough after slowing

[NW Explorer]

after cruising at 85 for a sustained time , when i slow to say 40, car feels lumpy and hesitant,clears when i speed up. does not happen in mixed driving ,just on m/way freeway. any ideas?

 

[Katmandu]

after cruising at 85 for a sustained time , when i slow to say 40, car feels lumpy and hesitant,clears when i speed up. does not happen in mixed driving ,just on m/way freeway. any ideas?

Two ideas actually.

#1. How does your engine act at idle while the vehicle is stopped ?? If it's still rough, chances are your lower intake gaskets need replaced (Recall item)

#2. Is your engine making a rattling noise on start up and upon accelleration between 2500-3000 RPMs ??

If so and it also surges when you hit the throttle (especially from a stop), I would pin it down on a bad chain tensioner.

Mine did the exact same thing.

A bad tensioner will cause SLACK to develop in the Timing Chain and when you accellerate, there is a hesitation while the Chain is taking in the slack. This causes the vehicle to surge or jerk forward.