Infrared Thermometer Test

What happens here

The presenter uses an ETEKCITY infrared thermometer to check the temperature of each exhaust manifold and coil pack. The theory is that a misfiring cylinder will have a lower exhaust manifold temperature because fuel isn't burning efficiently, and a faulty coil pack might also show a temperature anomaly. He notes the initial temperatures before starting the truck and then after it has warmed up. He checks both sides of the engine, carefully pointing the laser at the base of each component. He observes that one of the rear coil packs on the passenger side is significantly colder than the others, reinforcing his suspicion of an ignition problem.

Goal: Pinpoint misfiring cylinders by comparing temperature readings.