2019 Jeep Cherokee Spark Plug Type & Gap Guide

As an ASE-certified master technician, I've seen my fair share of misfires, rough idles, and check engine lights caused by neglected spark plugs. If you are servicing a 2019 Jeep Cherokee, getting the spark plug type, gap, and torque exactly right is crucial to keeping that engine running smoothly. The 2019 Cherokee comes with three distinct engine options: the naturally aspirated 2.4L Tigershark inline-4, the advanced 2.0L turbocharged inline-4, and the trusty 3.2L Pentastar V6. Each has its own specific ignition requirements.

Here is your comprehensive guide to 2019 Jeep Cherokee spark plugs.

Quick reference

Note: Always verify exact part numbers with your local dealer or parts supplier based on your specific VIN.

Why the right plug matters

Modern engines like those in the 2019 Cherokee are highly sensitive to ignition characteristics. Using the wrong heat range can lead to pre-ignition (pinging) if the plug is too hot, or carbon fouling if the plug is too cold.

Electrode metal is equally critical. The 2019 Cherokee relies on precious metals like Platinum (2.4L) and Iridium (2.0L Turbo and 3.2L V6) to achieve its 100,000-mile service interval. Iridium is harder and more durable than platinum, which is why it's required for the higher cylinder pressures of the 2.0L Turbo. Never downgrade to a standard copper plug in these engines; the coil-on-plug ignition systems are calibrated for the resistance of precious metal plugs, and copper plugs will wear out in a fraction of the time.

How to gap a spark plug

While most modern iridium and platinum plugs come pre-gapped, you should always verify the gap before installation. Dropped boxes in shipping happen all the time, closing the gap and causing an immediate misfire upon startup.

1. Use the right tool: For precious metal plugs, avoid the old-school "coin-style" gapping tools, which can snap off the brittle iridium tip. Use a wire-type gauge or a feeler gauge.
2. Measure gently: Slide the gauge between the center and ground electrode. It should pass through with a slight drag.
3. Adjusting the gap: If the gap is too tight, use the bending tool on your gauge to carefully pull back the ground electrode. Never pry against the fragile center electrode! Just a light bend is all it takes.

Replacement procedure tips

All three engines in the 2019 Jeep Cherokee use a Coil-on-Plug (COP) ignition system, meaning there are no spark plug wires or distributors to worry about.

• Upper Plenum Removal (3.2L V6): On the 3.2L Pentastar, the upper intake manifold (plenum) blocks access to the rear bank of spark plugs. You will need to remove the plenum to service the rear three plugs. Make sure you have a set of fresh upper intake manifold gaskets on hand before you start the job.
• The Anti-Seize Debate: Most modern NGK and Mopar/Champion plugs feature a special trivalent metal plating that acts as a release agent. Applying anti-seize to the threads of these plugs is not recommended, as it acts as a lubricant and can cause you to over-torque the plug, potentially damaging the aluminum cylinder head.
• Dielectric Grease: Always apply a small dab of dielectric grease to the inside of the ignition coil boot before reinstalling it over the new spark plug. This prevents moisture intrusion, stops voltage leaks, and ensures the rubber boot doesn't fuse to the plug's porcelain over the next 100,000 miles.

Known issues

While you won't encounter the infamous two-piece broken plug shells of the older Ford 3-valve V8s, the 2.4L Tigershark engine has a well-documented history of high oil consumption. If you are servicing a 2.4L, pay close attention to the old spark plugs as you pull them out. Heavy black ash or oily deposits on the electrodes indicate oil blow-by past the piston rings, which can prematurely foul the plugs well before the 100k-mile mark.

Additionally, be extremely careful when disconnecting the plastic locking tabs on the coil wiring harness connectors; heat cycling makes these clips very brittle, and they are prone to snapping.

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