Hey new guy here. I have a 98 caravan 3.3 4 speed. It runs fine shifts fine very smooth. the problem I have is when I come to a stop and sit there in Drive the transmission makes clunking, grinding noise until I take off and then it runs fine. I put it in N or Park it make no noise. Reverse same noise. Changed fluid, ATF+4 and filter. with the fluid change there were very small flakes of aluminum? not on mag of course. mag did have afro look to it. Has me stumped. Lots of mile on van 160K had it since 84K always changed fluid and filter. any guesses?

 

Is it a hard grinding noise like a grinder or more of a buzzing?

These are notorious for solenoid packs going. It will cause hard downshifts when coming to a stop (clunking) and will buzz as its trying to downshift.

 

it only does it when I am stopped and sitting for 5 seconds or more. in drive or reverse it like popping noise, grinding noise not buzzing. I pulled a solenoid that borg waner off another van at junk yard and grabbed all of the speed sensors. Seems like it makes the noise after fluid is warmed up some. I checked and cleaned ground under battery box. could never find ground strap that is suppose to be by starter.