This would be a 98 Honda Accord, 4-cylinder. If it wasn't an automatic, I would say that my wife and I have developed a habit of holding down the gas while pressing the clutch. It only seems to happen when it shifts from 1st to 2nd — the engine guns up to about 3500 rpms for a second, then returns to normal.

Aside from that, lately I've been hearing a thunk, maybe from the transmission, when I come to a stop. It seems to occur just a split second after stopping.

I drained the transmission fluid today and refilled it. The old fluid was pretty dark and smelly, but the new stuff didn't bring about any miraculous changes.

I'm hoping the problem here is the torque converter and not the transmission, but I don't want my hopes to color my diagnosis. Any thoughts?

 

it's slipping between the gears...fluid change won't help it. time for a rebuild or replacement. and no, the torque converter has nothing to do with the slippage.

 

Did you use honda automatic transmission fluid?

Does the D4 light start flashing when driving, or does the check engine light turn on when driving?

 

Nah, used something that claimed it was compatible with hondas. Autozone stuff. No D4 light, no check engine light. The symptoms are pretty mild, though the thunk is a recent addition.