A friend of mine called me on Friday and said that his car was acting very strange. He would hit the gas, and the engine would rev, but the car wouldn't go anywhere. It would not accelerate. Then he would stop, turn the car off for a little while, and he could go again, but only for a short while. His car made it home (he wasn't that far from home) and he asked me to come take a look at it. Now, I know my way around most things car, but automatic transmissions have always been kinda a "black art" to me. I don't know how to repair them, but I went over the looked at this car.
Sure enough, on a test drive, we didn't even make it to the end of the block before it started to exhibit the symptoms. Engine revs, no power. It felt like fluid starvation. Engine revving but no power being delivered. So, I looked up how to check the transmission fluid. Turns out, on a 2009 Chevy Cobalt 2.2, you don't check the transmission fluid. It's a filled for life system and checking it is very inconvenient. Long part of this story short, we found the bolt on the side of the transmission after much searching that you use to check the fluid level, and the fluid level was just fine. I asked him when he had the transmission serviced last? He said that the owners manual specifically stated that it does not need service, so he never has. The car has 261,500 miles on it and the transmission has never been serviced. Never.
With full fluid, a transmission that has never been serviced, and strange symptoms, I told him the truth, I have no idea what is going on. If it were fluid starvation I would expect to see leaks, there were no leaks, everything looked buttoned up just fine. In fact, aside from the transmission not delivering power, the car works and looks great. So, I told him to have it towed to a reputable placed I knew. He said ok, and that was that.... until tonight.
The more I thought about some of the things he described the car doing, the more confused I got. So, I called him up tonight and said that I would come over and change the transmission fluid and filter in his car. The more and I thought about it ,the only thing that made any sense was debris in the transmission pan that was being pulled into the filter when moving, then released when the engine was turned off. This was a completely a wholly crazy idea from my perspective. But, per the norm, my curiosity got the better of me, and I ended up over at his house. HOLY COW! We were not prepared for what we found. METAL CHUNKS in the transmission pan.
We were completely astounded, and still are. So, with a broken transmission on one hand, and a new filter and 8 quarts of Dexron-VI on the other, what is there to do? You put it all back together of course! We spend nearly half an hour cleaning up the oil pan and magnet. I've never seen anything like this before. So, we put in the new filter, new fluid, followed the filling procedure and... everything works. The angry sound the transmission was making has gone away, the engine and transmission work fine. We did a series of tests on the open road expecting any second to come to a stop, but no. Everything we did worked, all driving tests passed. It drives like this ever happened.
What the heck happened this this transmission? I mean, it sounds like the metal chucks and gunk were being sucked into the filter opening, and were clogging the system then being released, but how did this happen in the first place?
We were completely astounded, and still are. So, with a broken transmission on one hand, and a new filter and 8 quarts of Dexron-VI on the other, what is there to do? You put it all back together of course! We spend nearly half an hour cleaning up the oil pan and magnet. I've never seen anything like this before. So, we put in the new filter, new fluid, followed the filling procedure and... everything works. The angry sound the transmission was making has gone away, the engine and transmission work fine. We did a series of tests on the open road expecting any second to come to a stop, but no. Everything we did worked, all driving tests passed. It drives like this ever happened.
What the heck happened this this transmission? I mean, it sounds like the metal chucks and gunk were being sucked into the filter opening, and were clogging the system then being released, but how did this happen in the first place?
At 261K miles. The car doesn't owe you a thing. Look the gift horse in the face and keep driving. 
