Hey guys first post here hoping for some help on a very aggrevating problem. I have an 02 Dakota 4x4 ext cab 4.7L 58k miles and no idea on what tranny is in it. I'm going to give a lot of info here to try and get a good answer. When I'm going down the it will rev up about 200 RPM's out of no where. It happens fairly often too. It won't start doing it as soon as I get in the truck, usually about 30 mins of driving is when it starts (time to warm up first?). This is when it gets weird. It doesn't do it when I'm pulling a hill which makes me wonder if it's actually the tranny. It'll do it on flat ground, or when you crest a hill and start letting off the gas to maintain speed. Or it will do it when you get to the bottom of a hill when you start to push the gas again. It'll just rev for a second then go back to normal, then do it again and again. I know it's the converter going in and out but why? I had it looked at at the beginning of the year and the guy found some vacuum hoses that were very rotted and replaced them and it quit completely for about 6 months then very slowly started again. I just drove it tonight for about 100miles and it was doing it a lot again. The tranny oil doesn't smell burned at all and I had it changed and the filter cleaned about 8,000 miles ago. No odd shifts or anything like that just revs up about 200 RPM's. The check engine light came on about 2 weeks ago and I did the key on-off thing and the code was for "evaporative emmissions small" and I know what to look for with that. It's been doing it this time for about a month and if a sensor was going out it would show a code by now wouldn't it? Any idea's guys??

 

I forgot to mention also that it will also do this when I'm towing the boat and the OD is off. Again the same thing though only when I'm cresting a hill or on flat ground, not when I'm going up a hil.

 

No idea's on this?

 

I'm not sure how the Dakota works, but I've heard of similar problems with some Taurus transmissions. From what I recall, sometimes the problems were caused by a throttle position sensor sending a noisy signal to computer. This in turn would make the computer think it should be locking and unlocking the torque converter at the wrong times. I might try to look at the signal of that sensor. Just a shot in the dark though...

 

thanks

 

The TPS does sound like it could be the problem.

 

thats a accumulator problem, how good are your with transmissions?

 

I'm not good with tranny's at all. Example, what's an accumulator.lol

 

It's removing the pan and it adjusts the band more or less.

 

no its not....

id recommend going to a reputable tranny shop...