Check engine light is on and it shakes when accelerating

Hi,

This sounds like a severe misfire or internal engine issues. If the check engine light is flashing, that means stop driving ASAP because you will do serious damage to the engine or exhaust system. If it is a misfire then you are probably not burning the fuel that is going into the engine which means it is going into the exhaust which will quickly damage it and require replacement.

If it is making noise now as well then I suspect something in the engine let go. We need to start with getting the codes out of the computer. With the light flashing, you will have some DTCs that will point us in the correct direction.

Here is the warning from the owners manual that talks about this.

Let me know if you can get the codes and then we can go from there.

Okay. Does it still have the cylinder 5 misfire? I am assuming it does so did he take a compression reading? What about a cylinder leakage test? If you have a misfire this bad that it is vibrating and flashing the check engine light then just changing the spark plug and coil is just guessing, not diagnosing it.

I am not trying to be hard on this mechanic but if he didn't do these tests then I would suggest doing them yourself of taking it to someone that will understand what is happening.

https://www.2carpros.com/articles/how-to-test-engine-compression

Without knowing that compression and leakage are okay, I would not go much further because I suspect you have valve issue or an issue with the rings on that piston causing a dead misfire.

Okay. He can confirm this by doing a cylinder leak down test. Here is a video on how to do it:

https://youtu.be/WHli-wLy9_o

Once he confirms cylinder 5 has a leak, he can listen to the intake, exhaust, coolant reservoir, and oil cap to see where he can hear air. If he hears it from the oil cap, then this means air is going past the rings and into the crank case which confirms this needs to be torn down and repaired or replaced.