I have a 2000 dodge grand caravan ( 200,000k)that the tranny seems to be slipping. It drives ok around town for the most part except for some hard down shifting occasionally when approaching a stop light etc.. But when on the highway seems to have a hard time shifting into over drive. Problem is worse when the air is on or when I have my whole family in the van (6 of us ). Also makes a churping noise when shifting. This also is worse when on the highway, or on the highway with the air on. The churping noise only happens it seems when im trying to speed up, or needing to pass someone, or getting on the highway. Also getting terrible gas mileage about 17 miles per gallon on the highway. Can anyone tell me where to start with diagnosing this thing? Fluid looks great! Had a trans fluid change 25k miles ago. Also some trans fluid conditioner added. (Lucas) Please any suggestions would be greatly appreciated!

 

Do you have a 3 speed auto or a 4 speed auto ???

 

It is a 4 speed automatic.

 

Is the engine temp normal when driving, and have you ck for loose fan belts? The A/C belt is adjustable. Maybe take the a/c belt off and drive the van see if it runs any better. If it does runs better you may have a bad compressor.

 

I will take the a/c belt off and see if that works. The belts are all fine and the pully's have been changed by previous owner ( uncle). They did make a flapping noise for a while like they were loose but were not. The noise finally went away. Thanks for your suggestions, will try this and let you know if this works.