I recently bought a 2004 Toyota sienna from original owner @ 220k miles, well maintained. Transmission started whining lessens after low speed short drive, after a 1 hour high speed drive, a grinding noise started after that when starting out, I think this is the torque converter or clutch plates. I added 2/3 quart tranny fluid. I then got a code, number unknown, torque converter solenoid, on returning home 60 miles, tranny stopped shifting into 3rd gear & jerky an sluggish from 1st to 2nd & tranny fluid made burnt smell. "I did overfill tranny fluid" Tranny fluid drained/pan off filter looks bad / magnets have nothing fresh looking on them but some shavings. I am planning to change the tranny solenoids, fluid / filter, or maybe the valve body if you think I have good odds of a repair. I have learned a bunch from your advice, so Scotty "is the juice worth the squeeze?"
Thanks, Doc T.
Considering the mileage and the symptoms, plus the vehicle, I would say you likely will need a replacement transmission. I don't think trying to repair it will net you success.
Since those models are known for transmission problems and the mileage I would definitely look into replacement.
