Torque Converter acting up

Lately my torque converter has been acting up when the transmission isn't fully warmed up. It happens when the converter is locked and the engine is under load, such as going up a hill in 3rd or 4th gear. It seems to unlock slightly, then relock, creating a chuggle or fishbite effect, but a little moreso. It will continue to do this until I push the gas far enough down for a downshift and unlocked converter.

I had this happening before, but I never did find out what was causing it, as I had my plugs changed and the transmission fluid changed in the same service and the problem stopped after that. I'm wondering if maybe my transmission fluid's a little low and it can't maintain pressure when cold (as the fluid hasn't expanded yet) to keep the torque converter properly locked. I haven't had a chance to check the fluid yet, so I don't know.

I just went through this, you should run it with some seafoam and then have it changed in a couple of weeks.

But you are probably losing yr 4th gear, a very common and annoying problem, and the reason i just gave up on my intrigue.

Well I took it in the other day for an oil change and they checked the transmission fluid and said it was full and clean, so I guess it isn't low. However, I haven't driven it much since then, so I don't know if maybe they did add fluid and it's ok now.

As for the 4th gear thing, I don't think that's what it is, as I have absolutely no problem going into 4th or out of it. The problem is with the torque converter slipping. It does this in 3rd too, as lockup can be commanded under certain conditions. I will drive it this weekend and see if it's still being weird. If so, I may try pull the negative battery cable for a day or so to reset the PCM. I know this can help with some problems.