First of all, I'm currently drinking myself to sleep due to the daunting idea of having my engine pulled for a repair; this car is my daily driver.
It all began today with a routine oil change ...
I started my engine as usual, except something was amiss; there was a very noticeable knocking sound emanating from the right side of the engine, which I was able to pinpoint to the back of the passenger side valve cover. I allowed the car to idle for about 5 minutes and the knocking continued throughout that duration of time. I powered the car down and changed the oil.
After changing the oil, when I started the car again, the knocking was present at startup for the first few seconds, but disappeared for about 30 seconds and then returned again. Again, I let the car idle for about 5 minutes and the knocking persisted. I turned the car off to prevent engine damage in the case that something has seriously ****** up internally.
What do you boys think is going on? Has anyone experienced an issue like this before? What's the worst case scenario?
Details: 2005 Mustang 4.0L SOHC, 103,000 miles.