A cylinder 2 misfire in your 2017 Grand Cherokee often points to a failing ignition coil or spark plug. This specific issue, known as a 2017 jeep grand cherokee cylinder 2 misfire, can cause rough idling, poor acceleration, and even trigger the check engine light. If you are dealing with this problem, you are not alone—many owners face it, and the fix is usually straightforward.
In this guide, we will walk through the common causes, diagnostic steps, and repair solutions for a cylinder 2 misfire. You will learn how to pinpoint the problem and get your Jeep running smoothly again. No need for a mechanic if you have basic tools and some patience.
Understanding The 2017 Jeep Grand Cherokee Cylinder 2 Misfire
A misfire means the engine cylinder is not firing properly. For cylinder 2, this usually happens because of a weak spark, bad fuel mixture, or mechanical issues. The 2017 Grand Cherokee uses a coil-on-plug system, which means each cylinder has its own ignition coil. This design makes diagnosis easier but also exposes common weak points.
The most common culprit is a faulty ignition coil. When a coil fails, it cannot produce enough voltage to ignite the fuel-air mix. Spark plugs are the second most likely cause, especially if they are worn or fouled. Fuel injectors can also cause misfires, but they are less common on this engine.
Common Symptoms Of A Cylinder 2 Misfire
You might notice several signs before the check engine light comes on. Here are the most typical symptoms:
- Rough idle or shaking when stopped
- Loss of power during acceleration
- Engine hesitation or stumbling
- Increased fuel consumption
- Check engine light flashing or steady
- Strong smell of unburned fuel
If you see a flashing check engine light, stop driving immediately. A flashing light means the misfire is severe enough to damage the catalytic converter. That repair can cost over a thousand dollars.
Why Cylinder 2 Is Prone To Misfires
Cylinder 2 is located on the passenger side of the engine, near the front. It is not inherently weaker than other cylinders, but it can be affected by common issues. Moisture or oil leaks can short the coil or plug. Also, if you have a 3.6L Pentastar engine, cylinder 2 is close to the oil filter housing, which can leak oil onto the coil.
Another factor is heat. The cylinder 2 coil sits near the exhaust manifold on some models. Excessive heat can degrade the coil over time. This is why many owners report misfires after 60,000 to 80,000 miles.
Diagnosing A Cylinder 2 Misfire Step By Step
Before you start replacing parts, you need to confirm the misfire is actually on cylinder 2. A code reader or scan tool is essential. Here is the process:
- Read the trouble codes: Plug in an OBD-II scanner. Look for code P0302, which specifically means cylinder 2 misfire. If you see multiple cylinder codes, the issue might be broader.
- Check for other codes: Sometimes you will see P0300 (random misfire) or codes for cylinder 1, 3, etc. This can indicate a fuel or mechanical problem.
- Swap the coil: Move the ignition coil from cylinder 2 to cylinder 1. Clear the codes and restart the engine. If the misfire moves to cylinder 1 (code P0301), the coil is bad.
- Swap the spark plug: If the coil swap does not change the misfire, try swapping the spark plug from cylinder 2 to another cylinder. If the code follows, replace the plug.
- Check the fuel injector: If both coil and plug swaps fail, the injector might be clogged or failing. You can swap injectors similarly, but it is more involved.
This swap method is the fastest way to diagnose without guessing. Always clear codes after each test to get accurate results.
Tools You Will Need For Diagnosis
You do not need a full mechanic set, but a few items help:
- OBD-II code reader (basic models work fine)
- Socket set with extensions
- Torque wrench for spark plugs
- Dielectric grease for coil boots
- Shop towel or rag
Most of these are cheap and reusable. A decent code reader costs around $20-30 and pays for itself quickly.
Visual Inspection Tips
Before swapping parts, do a quick visual check. Look for:
- Oil or coolant leaks near cylinder 2
- Cracked or damaged spark plug wires (if equipped)
- Loose or corroded electrical connectors
- Buildup of dirt or debris around the coil
Sometimes a simple cleaning or tightening fixes the issue. If you see oil on the coil boot, clean it with brake cleaner and check for leaks.
Common Causes And Fixes For Cylinder 2 Misfire
Once you know the misfire is on cylinder 2, you can focus on the likely causes. Here are the most common ones and how to fix them.
Faulty Ignition Coil
The ignition coil is the number one cause. On the 3.6L Pentastar engine, coils are known to fail around 70,000 miles. Symptoms include a rough idle and loss of power. Replacing the coil is simple:
- Disconnect the battery negative terminal
- Remove the engine cover (if equipped)
- Unplug the electrical connector on the cylinder 2 coil
- Remove the mounting bolt (usually 8mm or 10mm)
- Pull the coil straight out
- Install the new coil with a dab of dielectric grease on the boot
- Torque the bolt to 8-10 Nm (check your manual)
- Reconnect the battery and start the engine
Use OEM or high-quality aftermarket coils. Cheap coils often fail quickly.
Worn Or Fouled Spark Plug
Spark plugs should be replaced every 30,000 to 60,000 miles. If they are old, the gap can widen or electrodes wear down. Fouling from oil or carbon buildup also causes misfires. Replacing the plug is similar to the coil swap:
- Remove the ignition coil as described above
- Use a spark plug socket to remove the old plug
- Check the gap on the new plug (usually 0.043 inches for 3.6L)
- Hand-tighten the plug, then torque to 18-22 Nm
- Reinstall the coil and connector
Always use the correct plug type. For the 2017 Grand Cherokee, NGK or Champion are common choices.
Clogged Or Failing Fuel Injector
Fuel injectors can get clogged with deposits over time. This causes a lean condition in cylinder 2, leading to misfires. Symptoms include hesitation and poor fuel economy. You can try a fuel system cleaner first, but sometimes replacement is needed.
To test the injector, swap it with another cylinder. If the misfire follows, replace the injector. This job requires removing the intake manifold on some engines, so it is more complex.
Vacuum Leaks
A vacuum leak near cylinder 2 can cause a lean mixture and misfire. Check for cracked hoses or loose intake manifold gaskets. Use a smoke machine or spray carb cleaner around the area while the engine runs. If the RPM changes, you found a leak.
Mechanical Issues
Less common but possible are mechanical problems like low compression, a burnt valve, or a broken piston ring. These usually cause persistent misfires that do not respond to part swaps. A compression test will confirm this. If compression is low on cylinder 2, you need professional engine repair.
Preventing Future Misfires
Once you fix the cylinder 2 misfire, you want to avoid it happening again. Here are some tips:
- Replace spark plugs and coils as a set if they are near the end of life
- Use high-quality fuel to reduce deposit buildup
- Keep up with oil changes to prevent sludge
- Check for oil leaks regularly, especially near the oil filter housing
- Clean the throttle body every 30,000 miles
Regular maintenance is the best prevention. A well-maintained 3.6L engine can last over 200,000 miles without major issues.
When To See A Mechanic
If you have tried swapping coils and plugs and the misfire persists, it is time for professional help. A mechanic can perform a compression test, leak-down test, and fuel pressure test. They can also check for internal engine damage. Do not ignore a persistent misfire—it can lead to expensive repairs.
Frequently Asked Questions
Can I drive with a cylinder 2 misfire?
It is not recommended. A misfire can damage the catalytic converter and cause other engine problems. If the check engine light is flashing, stop driving immediately.
How much does it cost to fix a cylinder 2 misfire on a 2017 Grand Cherokee?
The cost varies. A single ignition coil costs $30-60, and a spark plug is $5-10. If you DIY, the total is under $100. At a shop, labor adds $100-200 for diagnosis and replacement.
Will a bad coil cause other cylinders to misfire?
Usually no, but a failing coil can cause random misfires if it is intermittent. It is best to replace the faulty coil as soon as possible.
What is the most common cause of a cylinder 2 misfire on the 3.6L engine?
The ignition coil is the most common cause. Spark plugs are second. Fuel injectors and vacuum leaks are less frequent.
Can a bad oxygen sensor cause a cylinder 2 misfire?
Indirectly, yes. A bad oxygen sensor can cause the engine to run rich or lean, which might lead to misfires. But the direct cause is usually ignition or fuel related.
Final Thoughts On The 2017 Jeep Grand Cherokee Cylinder 2 Misfire
Dealing with a cylinder 2 misfire can be frustrating, but it is often a simple fix. Start with the ignition coil and spark plug swap method. If that does not work, check for vacuum leaks or injector issues. With basic tools and a little time, you can get your Grand Cherokee back on the road.
Remember to always use quality parts and follow torque specifications. If you are unsure, consult a repair manual or a trusted mechanic. The 2017 Grand Cherokee is a reliable vehicle when maintained properly, and a misfire does not have to be a major problem.
We hope this guide helped you understand and fix the issue. Safe driving, and keep your Jeep running strong.