Greetings forum folk,

I have a 99 caravan w/ the 3L engine. 151k miles. I've had low power with it lately, taking a lot to get up to speed. I also have been averaging about 17MPG with mostly hwy driving which seems pretty poor. Additionally when idling I can feel a bit of a stumble/rough idle.

I'd like to solve this issue, and I'm looking for a direction. I picked up a block tester and plan to test for combustion gasses in the coolant just to rule out (or confirm) head gasket issues. I'm sorta leaning towards a lean condition/vac leak, and I'm hoping to have a scan tool soon that can get me some live data.

I am probably due for a tune up; I've put around 25k on it since I"ve owned it, and I'm not sure when the previous owner last did any type of plugs/wires/cap/rotor. I also don't like to throw parts, and much prefer to have evidence to back up my decision.

 

When was the timing belt and timing belt tensioner last changed? Low power and poor gas mileage could be related to a timing belt that has slipped a tooth on a sprocket... or was not properly lined up on a recent installation.

Another possibility could be related to a clogged or restricted exhaust system (converter perhaps).

Head gasket problems are less likely on a 3.0.

 

Disagree on the timing belt/tensioner. I've never needed to replace either, other then when a water pump went out.

Converter is a definite possibility.

Just needing the plugs/wires/cap/rotor done can also be contributing to all the issues, seeings it's at 150+k. I would start there seeings it most likely needs to be done anyway.