I have a 2013 Chevrolet Cruze LS - L4 - 1.8L 1796cc 110ci FLEX MFI vin H type LUW - 4 valve DOHC. It currently has 80,200 miles, and I bought it a dealership pre-owned in July of 2021. I have 5 months with it and it is giving me some trouble. I got the vapor canister purge valve solenoid and the valve cover replaced because my check engine light came on and my mechanic told me those parts needed to be replaced. After the car was serviced the light went off and was running good for a couple of days, when afterwards my car started to want to turn off while I was driving. My rpm was going up and down and I had trouble accelerating because the car didn't want to advance. The car never turned off even though it felt I was going to, so I stopped and checked if I can hear a noise or something from under the hood but it was acting normal. I expected my check engine light to come on also but it didn't. So I used it later on that night and it was working fine. The next day I used it, it did the same and it felt like I was riding a horse, going back and forth inside my car, and I also saw almost like a huge white cloud come out of my exhaust. And every time I go up a hill or a bridge my car does the same, like it wants to turn off and like it's losing power. I feel like I have to step on the gas pedal a little more than usual when I go up a hill or sometime when I try going at freeway speed on the freeway. I have also seen that I'm losing oil. I check the dipstick and it feels dry and i know it shouldn't feel that way. It doesn't even reach the tip of the dip stick. I put in a quart that was left from my last oil change and it did appear on my dipsrick but barely making the tip of the dipstick. I read online that all these symptoms could be a bad piston ring. I just wanted to ask and see if it really could be a piston ring with all the symptoms that I just listed. The weird part is that my check  engine light hasn't come on yet.