Dodge - Grandcaravan :: 1999 - Sluggish Suddenly - Low On Power

1999 grand caravan 3.0L approx 250,000 Kilometers / 155,000 miles

Yesterday morning I was on my way to work, highway mainly. We have some cold weather here lately, say this morning low -20c range with a light wind. I was about 15 minutes ( 1/2 way & running fine ) while into my drive when i stopped at a light ( vehicle at operating temp )... light goes green, then i accelerated i felt a slight lurch/hesitation, almost a miss but it kept going and then it seemed to be slightly over revving / under powered to get up to the typical highway speed of 80 KMH / 50 MPH in that area.

It felt a bit low on power and a bit louder than normal, i chalk that up to the fact that after the "lurch" it felt like the trans was, I don't want to say slipping but kind of. It would settle into its final high gear a tad later than normal.

I will say it seems like it is reacting like when you accelerate on a slippery or icy road and the speedometer would/should swing up but you would be creeping or not moving as fast as the speed indicated, but the traction is fine, and the speedo just indicates the actual speed traveling while my foot is in it and it should really be spinning its wheels. It does get up to speed but is lagging...

Ran poorly when i cold started it after the 5 hours at work but made it home with all the same conditions. It smoothed out some as it warmed up

When I am parked the idle seems to hunt in a high low high scenario that repeats itself every few seconds, No codes stored, no CEL, no codes while idling, or under forced load IE running in gear with foot on brake and loading engine. scanned it when i got home.

All fluids are up, the trans fluid is just above the add mark but clean. I did a water pump, timing belt and tensioner a couple months ago...the pump was a weeper, hated that job. New air filter and plugs,cap, rotor wires installed then, say early NOV.Cleaned the throttle body then as well. No fluids on the ground since then. all wires are properly inserted in the cap. I had a cyl misfire code just after the new wires were installed 2 months ago cyls 1,3,5 but that was the cap end terminals were just slightly loose. a push back on and no codes no miss after that, till yesterday? full tank of gas two days ago and have about 100 kmh/60 miles on that tank.

all of these conditions are slight, like they are definitely noticeable but none are extremely worse. I'm thinking sensor? I can snap the throttle when it is running in park and it revs but seems like its not as crisp. I know my dad had trans issues with his 89 GC 3.0L but other than this water pump of late , this thing has treated us very very well. I'm not leaning towards trans, especially since the idle seems wonky/erratic.Previously it wouldn't snap your neck ,but it would downshift and pass or get up and go when you asked, now, not so much...

UPDATE ....THIS MORNING I took it out for a small drive this morning after the school bus came, ran really rough on the cold start, didn't stall but was a RUH - RUH - RUH labored running before engine warmed up. Down the road waiting at the bus stop it stall once while waiting for the bus to arrive. started right back up no issue.

still have a rough ruh ruh ruh ruh kind of sensation like one beat per second timing, very strong when cold, smoothed out to about 90% gone when warmed up but still noticeable. can get it to spin the tires on the icy roads but doesn't seem to accept the acceleration applied to the pedal like it should. i have my foot in it it should either downshift and charge or spin and swing the speedo up... but if i did get the wheels spinningthey would just climb up slower than normal like 30 mph 40 kmh and climbing when it should be climbing and reading the wheelspin at a much faster rate like 40-50 mph and . no codes active or stored ... my OBD tool has an emission " guage " on it likea stoplight, green yellow and red. it does work when i had the misfire after the new wires ( see water pump re&re listed above ) the light was yellow, I refit the wires in the cap and cleared the miss fire code and it read green. figured that tidbitwas worth mentioning.

basically it feels like the engine is being held back, like a heavy , heavy spring would on a carburated vehicle. it still works but has a wet blanket on it.

also will mention in the past week or two I'd say i may have noticed a slightly lower idle speed when stopped at a light but like i mentioned the heater fan and lights aregetting used more often at higher frequency as it has been cold and the sun sets at about 4 pm this time of year

temp here this morning -25c / -13f