Random Ticking and Misfire

Only 1,200 miles after replacing all the coils and plugs the car developed a random ticking sound and misfire at idle. It would disappear even with the slightest increase in engine speed over idle. The ticking sound, which was coming from the #6 cylinder area, turned out to be sparking. I would see sparks at random near the ground bolt near #6 and also on other random areas on the RHS intake manifold. Here is a video clip. I was never able to capture the sparking on camera.

I inspected all the grounds. They were in excellent condition. I even ran the car with the battery -ve directly connected to the alternator body. But it made no difference.

I physically couldn't see anything wrong with the #6 coil or spark plug. I first replaced the spark plug, but that didn't do anything. So I decided to replace the #6 coil as well and that seems to have fixed the issue.

I removed and refit the RHS intake manifold twice while troubleshooting. I've become quite good at it.

Here are a list of common torque specs if you need to R&R the intake manifold.

	n.m	lb.ft
Spark Plugs	16-20	12-15
Ignition Coils	5-7	4-5.5
Coil Cover	2.5-3.5	2-3
Inlet Manifold	8-12	6-9
Fuel Rails	8-12	6-9
Cross Brace	49	36
Manifold Brace	8-12	6-9
Corner Braces	49	36