Changed transmission filter now trans is screwy

Just purchased a 2001 Protoge. Changed the trans. filter and fluid at it had obviously not been done. We overfilled the the fluid so we dumped some out of the pan. The fluid that came out was very dark, not like the new stuff we put in. Once we got it to the correct level we took it for a spin and it ran fine. Now, this morning, it’s hesitating, lurching, running the rmp to 4500 before it changes gears. What have we done?!?!

I think that you need to do a full fluid exchange and then change the filter again.

Dark is bad. This transmission is probably going to die soon, no matter what you do. For now, get fresh fluid in there and keep your fingers crossed.

You didn’t have the car inspected by a mechanic before the purchase, I assume?

I think that you need to do a full fluid exchange This is one of the few situations that I would agree that a fluid exchange might be useful. (because the oil stuff was burned. That does not mean I am certain it is the fluid, but ?..

Did you recheck the fluid level AFTER you drove it and had the engine/trans at normal operating temperature?? THATS when it needs to be checked and topped off at. Also, when you changed the filter did you seat the filter all the way?? Did you change the filter “O” ring??

transman

We did check the fluid level after driving and the engine had been running for quite some time. The filter seemed to be seated correctly. The manual did not require changing the “o” ring. We did replace the gasket.

You didn’t report slipping, just extremely elongated shifting. If it was an older hydraulic system, it would point to a stuck governor or a throttle position valve. I haven’t a clue here. I’m sure there’s a TCM that’s going to tell you something when read. It appears to be interpreting that you’re at near WOT.

I’d still exchange the fluid via the cooler lines.