yavinbase

Hi everyone. I've browsed these forums many times, and they have been a great resource. This is the first time I'm posting. I got into a relatively minor accident in my automatic 2002 4runner recently, and I am having problems with it now. I'm looking for help to figure out what the root of the problem is and how to fix it.

Symptoms:
The car starts fine. It idles pretty smoothly, and I can shift smoothly into Park, Drive, Neutral and Reverse (haven't tested the other gears). If I press the accelerator when the car is in park, it behaves fine. However, when I actually try to drive the car forward, it has difficulty shifting between gears. The car waits until it hits 2500 RPM to shift from 1st to 2nd and from 2nd to 3rd and when it finally shifts, the car jerks violently into the next gear and then the engine drops to 2000 rpm. When it reaches the mid-2000s, something sounds off (maybe like something is rubbing wrong?), but I'm not used to running the engine that high, so I don't know how bad the sound actually is. Also, the 4WD HI light is on even though the controls aren't in the "on" position.


Backstory:
A few months back, my car slid (rainy conditions) into something at 5-10mph. The bumper was damaged and a metal plate slid through the front radiator and halfway through the engine/tranny radiator. I didn't notice this plate. Really stupidly, didn't check the car out before I drove it a day or so later. After 20 minutes, the car overheated (there was smoke) and I pulled off to the side of the road. The radiator was (mostly) empty. I let the car cool down, put some antifreeze in there and drove it 5 minutes to the mechanic. The car ran smoothly - no issues.

My mechanic ran into personal issues and sat on the car for a few months. We eventually towed the vehicle to my place.


What I have done so far:

1. I did not have the ignition key anymore so I contacted a local locksmith and he made me a new pair of ignition keys (which required reprogramming the ECU).
2. For reasons that are unclear, the battery was dead (recharging it didn't help), and I had to replace it.
3. I replaced the radiator with a Koyo A1998. While draining the old radiator, I looked for any signs of a strawberry milkshake in the antifreeze, but didn't see anything (there was enough fluid remaining that I should have been able to see it if it was there). I turned on the vehicle, drove it a few hundred feet, and experienced the above symptoms.
4. I was still worried that I might have a milkshake situation, so I checked the transmission fluid. It was very low, but looked like new fluid. I filled the transmission fluid, drove it a few hundred more feet, and there was no improvement.

Can anybody give me ideas for what might be wrong/what to check? The 4WD light being on seems suspicious. Is there one computer that controls both the transmission and the 4wd that might be damaged? Could a bad ECU flash do this?

yavinbase

For anyone with similar issues, I seem to have found a solution: I tried shifting between 4WD HI, LOW and off, and the car now seems to be fixed. I'll let you know if there are any updates.