Recently purchased a 2005 Grand Caravan with a 3.8L. It has around 71k miles. One thing we recently noticed is when driving around at higher gear going up slight incline it experiences a slight vibration. If you slightly increase gas it continues until you depress the gas pedal enough to actually make the transmission kick down to a lower gear. It is mainly noticeable at very low speeds/RPMs and going up an incline. It does not feel normal, but this is our first Grand Caravan so I wanted to see if anyone else has experienced this and what they think it might be. Overall I am very happy with the van, but this is a little annoying.

 

Welcome to DF
The slight vibration, could be tires. Which would be normal. Your van is a front drive and may feel not feel normal to you. You also could be feeling the torque converter going in to lock up. Also these transmission do shutter in reverse and so does all the chrysler cars and trucks, this also normal.

 

Thank you for the reply. I thought it might be the torque converter, but this is my first Dodge so I wanted to make sure and run it past someone who knows a little more about these vans than I do.

Thanks

 

After some further research I don't think it is the torque converter. I was looking under the vehicle the other night for anything that might be loose and vibrating because I have heard sometimes the heat shield around the exhaust can make some noise as well. I noticed that there is a bracket mounted under the driver side that houses a plastic like container. I was not able to fully get under the vehicle to see that the container is but it has about three hoses going into the back of it and some coming out the front. The bracket is supposed to have a bolt at the back running through a rubber spacer/insulator and then bolts into the frame. The bolt was loose and then I noticed that it would not screw into the frame. It appears the nut that should be on the inside of the rail is not there anymore. I have a feeling this is what is causing my vibration. Does anyone have any suggestions on how to get this thing bolted back down securely?

 

Heavy duty zip tie perhaps.

 

That container is part of the evaporative emissions system and at least on our 2001, it does just kind of hang there.
On our 2001, I had it back at least a half a dozen times for a slight but noticeable surging or bucking under exactly the conditions you describe. The service manager took it for a ride and said that he too could feel it but had no solution so I finally gave up. Now I find from Alldata that there is a TSB that involves reflashing the TCM but of course, it's too late to get Chrysler to do anything, at least on their nickel.
Check to see if there might be something on the 2005 that addresses the same problem.

 

I bought a 05 Caravan in April '09 with 70K miles. I noticed in the fall last year that crusing (light throttle) at 40-50 MPH, there was surging in the drive line. NO CEL or codes found. Seems like the engine is running too lean. If I pulled the tranny down to 3rd vice OD, it would mostly go away or if more throttle was applied.

I now have 88K miles. Since I do almost all my own work, I did replace the spark plugs and wires plus dropped the tranny pan and change the filter, cleaned the pan magnet and replaced the approximately 4+ quarts with new AFT+4 (not a complete fluid change out).

Still has the surge but seems to be reduced with the A/C on or either coasting or more than light/cruise throttle. I was thinking it might need a soft ware update.