lawdawg22
New member
Hello everyone, so I've been got my moms friends 2012 Sonic Hatchback that when I got to it they told me that a mechanic in town told them it was a broken timing belt because the cams weren't moving when cranking. They said he opened the oil cap, looked at the cam, and see it moving. So not going off the other mechanics word due to his reputation to rip people off, I checked for myself. I removed the cover where the coils were, and when I pulled the whole unit out the last two plugs on the drivers side had so much oil in the plug well's that it was almost halfway up the tube. Moving on I removed the valve cover, and upper timing cover. I had the owner crank the engine over while I looked at the cams and they were both moving as they should be. I inspected the belt, and didn't even see so much as a scratch, or even cracks on the belt itself. Not having checked the timing until I decided I wanted to fool with it, I decided to get as much of the oil out of the plug wells as possible, then just reinstalling what little I could to get it to at least crank to see what it sounded like. Now when he first tried to start it before I removed anything from the car it sounded like the car had zero compression and just bit the dust, but after I had taken everything apart and cleaned it all back up including what must have been a half of a cup of oil in each tube it sounded like a normal engine cranking for 5-6 seconds and went right back to sounding like it had low compression. Not messed with a lot of interference engines, or many running belts either. Most of the engines I work on are big bore engine with timing chains, and finding a issue is pretty simple with not nearly as many sensors or tiny little parts. All this being said, I need to ask the SONIC community, anyone ever experience this? I know that the spark plug wells is the valve cover gasket worn out and the areas where the wells are they're worn out, but after cleaning the coil, wells, and picking through some of it the engine sounded better than before. I need to get a compression test done on it to see if its a bent valve or if its the rings. When I checked the codes there was a camshaft position sensor code, crankshaft position sensor code, a o2 sensor code and battery voltage lower than normal(which I already knew, because the battery was dead, and had to use my jump pack).. the owners exact comments on the symptoms of the car was: the car sounded like it had been put in reverse while it was already in gear. They thought their grand daughter had done it, but wasnt sure, so they pulled over to the side of the highway and shut it off immediately. When they went to try and start it again, its doing exactly what it is now. I'm just wondering if that coil had gotten so much oil in the tubes while sitting in the wells that two of those cylinders aren't getting any fire due to the massive oil leak. To me it sounds like two cold cylinders, while the other two have spark, and the whole issue with the possible bent valve could be in part the dead cylinders. I'm not sure the timing belt skipped a tooth yet or not as I don't have the vehicle here to pull the wheel off to get the balancer off to check TDC, and see if its skipped a tooth or not. The belt sure has plenty of tension to it. So we'll see, What's your folks best guesses?
or ECU since the battery voltage code is linked to ECU communication failure. The ECU does have spots from fluid on its casing. That and brake fluid found on the ABS harness, the housing cracked and fluid went into the controller was another red flag.