2012 Sonic Ruined by dealership

[pwyskowski]

I took my 2012 Chevy Sonic into Sawyers Chevrolet of Dewitt, Michigan to fix an oil leak (there was oil on the front of the engine). They said it was the valve cover and "fixed" it. When I got my car back, it was suddenly a lot louder and making a strange whistling/screeching noise. I pulled over and checked the oil to find it empty. I contacted Sawyers via phone and through their website. They told me that their service department was closed until Monday. They did not respond until I called them again late Monday morning and was insistent on talking to the Service Manager. I had them tow it over there as I was afraid to drive it in that condition. After waiting all day, they called me to say that it had plenty of oil and was only down a quart and that they didn't hear any "noises". I picked up my car and it still continued to be loud and make strange noises. The next morning, the engine light came on blinking with a solid oil light, this lasted for about a minute before going out. I have footage from my garage security camera showing the difference in sound between the time I took my car in and when I got it back.
I firmly believe that they ruined my engine. It only has about 54,000 miles on it and I'm afraid the engine will blow when I'm driving it.

Here is footage of the difference in the sound my engine makes.
https://youtu.be/x5Dh5gsQQr8

Any advice would be appreciated.

 

[pwyskowski]

Following up on this (if anyone cares). The engine is now misfiring like crazy. (Error code says Cylinder 4).
I took it to a mechanic that wasn't at a dealership since the dealerships kept screwing me over.

NOTE: This 2012 Sonic only has 55K on it.

He couldn't find anything physically wrong with it. He did say that the sparkplugs were completely gunked up with some mystery substance so he replaced those and tuned it up. He also checked the fuel injectors and flushed the fuel system Alas, it still misfires when the engine is cold. He told me that I will have to go to a dealership because it might be a computer problem that he can't read.

Anyone else have this issue and know what the fix is?

 

[Sonic-Mike]

Post should now show properly.

 

[Bl4d3]

Following up on this (if anyone cares). The engine is now misfiring like crazy. (Error code says Cylinder 4).
I took it to a mechanic that wasn't at a dealership since the dealerships kept screwing me over.

NOTE: This 2012 Sonic only has 55K on it.

He couldn't find anything physically wrong with it. He did say that the sparkplugs were completely gunked up with some mystery substance so he replaced those and tuned it up. He also checked the fuel injectors and flushed the fuel system Alas, it still misfires when the engine is cold. He told me that I will have to go to a dealership because it might be a computer problem that he can't read.

Anyone else have this issue and know what the fix is?

Judging by the sound of the video, it sounds like an air intake leak. It could be that they tore your intake pipe.
Additionally, considering they 'fixed' your valve cover, I'm assuming they removed it. It could be that they didnt reconnect the PCV hose back to the throttle body or lost a clip and it isnt being secured on properly.
I assume you have a 1.8L judging by how your engine sounds.

Check this video out, they show where the PCV valve and pipe is located :

Here's a test. If you floor your gas pedal (only for a second but very quickly) does it sound like your car has a performance filter installed? If so, that would indicate an air leak. This is of course assuming you dont have a performance air filter installed