Fix or sell my '09 Aveo with ongoing maintenance issues
TL;DR: My 09 Aveo w/ 114k miles has an 'undiagnosable' transmission issue, a scraping/thunking noise from the rear and an elusive coolant leak. It's paid off, but my credit is trash, I have no savings, but I need a car. Fix or dump before I drive cross country for work.
I panic-bought a used 09 Aveo (automatic) w/ 55k miles on it about 3.5 years ago from Carmax after my Fit was totaled. I owned an 07 Aveo before the Fit, drove it until it died at 226k miles, so I figured the 09 was a safe bet. I was incorrect. The CEL came on 10 days after I bought it and that was only the beginning. I have a stack of repair receipts nearly a half inch thick, thankfully the warranty has covered about 90% of the repairs.
The car is now around 114k miles (I'd do about 20k/year pre pandemic), and still having issues most recently:
-an intermittent transmission issue. The same few fault codes have been popping up for over a year and a half: U0001 and P0700. Usually when they first show up, the dash gauges go haywire, dropping to zero, and then back up, especially the speedometer (https://drive.google.com/file/d/1C8B...ew?usp=sharing). The behaviors and the CEL will go away after a few trips. Last May I took it to a transmission shop and during their diagnosis, the cleared code didn't come back during their test drive, so they said to come back when it did. After two months, CEL returned, I took it back to the shop, and they couldn't figure out what was wrong. They said replacing the fuse box might fix it. The codes didn't return until last month (March), and my regular shop said to take it back to the trans shop, but the CEL hasn't returned since the codes were cleared, and it just sort of runs poorly (also nothing new).
-a metallic scraping and thunking noise from the rear driver's side. Also something the shop couldn't 'replicate' even though it happens most of the time while driving. Worse when going over bumps, occasionally sounds like a metal rattling sound before clunking loudly. The scraping is really bad when reversing.
-an elusive coolant leak. When I took it to a shop less than a month ago and they couldn't find a leak, even though my coolant tank was empty and I watched it drip (passenger side, near the tire). But they couldn't recreate the leak in the shop, but replaced the coolant take cap because it didn't 'close all the way' and suggested that's why I was losing coolant. Since then, the leak has now moved to the driver's side, just behind the bumper, but only leaks after the car has been running for a while and turned off. I'm 95% sure it's coolant (I let it drip into a white container, and it definitely smells like it), and the tank level is dropping. You can definitely smell the coolant outside of the vehicle after it has been running. Two years ago the oil cooler was replaced because it was leaking internally and externally, intermixing and ruined the hoses.
I dumped a bunch of money into it at the end of December (new front brakes, shocks, fixed exhaust leak) in hopes that it would last me at least another year, and now the coil pack and valve cover gasket were replaced just last month (warranty covered). The shop I take it to definitely tries to push extra repairs ($70 to replace a brake light bulb, LOL), but they take my warranty.
Is it time to just throw in the towel on this car? I only just paid it off, my credit is trash, and I've been unemployed since last March because my entire industry basically shut down, so financing will be difficult, and my savings are shot. I finally have a new 4 month gig, but it's 1500 mi cross country in a mountainous region, and I'd need a car while I was there (no public transportation).
