🔧 Grand Cherokee - Ignition Coil Replacement

You’ll be removing the engine cover, unplugging each ignition coil, unbolting it, and swapping in new coils on your Grand Cherokee. This restores strong spark and can fix misfires, rough idle, or check-engine lights related to coils.

Difficulty Level: Beginner | Estimated Time: 1.5–2.0 hours

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⚠️ Safety & Precautions

• ⚠️ Work with the engine completely cool to avoid burns from hot parts.
• ⚠️ Park on level ground, shift to Park, and set the parking brake.
• ⚠️ Disconnect the negative battery cable before touching ignition wiring to avoid short circuits.
• ⚠️ Keep metal tools away from the battery positive terminal to prevent sparks.
• ⚠️ Do not pull on wires; only handle connectors and coil bodies.

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🔧 Required Tools

You'll need the following tools for this repair:

• 🔹Ratchet handle 3/8"
• 🔹3" socket extension 3/8"
• 🔹6" socket extension 3/8"
• 🔹8mm socket
• 🔹10mm socket
• 🔹1/4" drive ratchet handle
• 🔹1/4" drive 6" extension
• 🔹Inch-pound torque wrench (30–150 in-lbs range)
• 🔹Foot-pound torque wrench (5–50 ft-lbs range)
• 🔹Flathead screwdriver (medium size)
• 🔹Trim clip removal tool (specialty)
• 🔹Needle-nose pliers
• 🔹Dielectric grease applicator swab
• 🔹OBD2 scan tool (basic) (specialty)
• 🔹Fender cover
• 🔹Mechanic’s gloves
• 🔹Safety glasses
• 🔹Shop rags

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• 🔹Ignition coil set (5.7L Hemi, 8 coils) - Qty: 1 set (8 coils)
• 🔹Dielectric grease for ignition components - Qty: 1 small tube
• 🔹Engine cover retaining clips - Qty: 2–4 (optional, if any break)
• 🔹Air intake duct clamp(s) - Qty: 2 (only if existing clamps are damaged)
• 🔹Battery terminal cleaning brush - Qty: 1 (optional)
• 🔹Spark plug set (5.7L, 16 plugs) - Qty: 1 set (optional but recommended)

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📋 Before You Begin

• Park the Grand Cherokee on a flat surface, shift to Park, and set the parking brake.
• Open the hood and install a fender cover to protect the paint.
• Turn off all electrical loads (lights, radio, AC) and remove the key from the vehicle.
• Disconnect the negative battery cable:
  • Use a 10mm socket to loosen the negative terminal nut.
  • Lift the cable off and tuck it aside so it cannot spring back.
• No infotainment or special scan-tool preparations are required before starting this job.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove engine cover

• Lift the decorative plastic engine cover straight up; it is held by rubber grommets.
• If it feels stuck, gently pry up near the corners using your flathead screwdriver while supporting the cover with your other hand.
• Set the cover aside where it will not get stepped on.

Step 2: Identify ignition coils on both banks

• The 5.7L V8 has two banks of cylinders: driver’s side and passenger’s side.
• Each ignition coil is a small rectangular unit bolted on top of the valve cover area with an electrical connector and a rubber boot going down to the spark plug.
• On this engine you will see multiple coils along each side; you will replace them one at a time to avoid mixing connectors.
• Do one coil at a time to avoid confusion.

Step 3: Gain access if intake duct is in the way

• Some coils, especially near the front, may be partially blocked by the air intake duct.
• Use a flathead screwdriver to loosen the duct clamps at the throttle body and airbox if needed.
• Gently wiggle and lift the duct out of the way and place it aside.
• Torque for intake duct clamps on reassembly: 3–4 Nm (27–35 in-lbs)

Step 4: Disconnect electrical connector from first coil

• Locate the locking tab on the coil’s electrical connector.
• Press down the tab with your thumb or use needle-nose pliers gently if space is tight.
• While holding the tab, pull the connector straight back off the coil. Do not yank on the wires.
• Wiggle connector slightly if it feels stuck.

Step 5: Remove first ignition coil

• Use an 8mm socket with a 3" extension and 3/8" ratchet to remove the coil mounting bolt(s).
• There is typically one bolt per coil on this engine holding it to the valve cover area.
• Once the bolt is removed, pull the coil straight up by its body to remove it from the spark plug.
• Twist slightly as you pull to break the seal of the rubber boot.
• Factory spec for coil mounting bolt on installation: 8–10 Nm (71–88 in-lbs)

Step 6: Inspect spark plug area

• Look down the spark plug well with a light to ensure there is no oil, water, or debris.
• If you see light dust, gently blow it out or use a clean shop rag wrapped around a screwdriver to wipe the top area (do not drop anything into the well).
• If the spark plug looks very worn and you have new plugs ready, this is a good time to replace them, but that is an additional job.

Step 7: Prepare and install new coil

• Apply a thin film of dielectric grease inside the rubber boot of the new coil using the applicator swab.
• Position the new coil so the boot lines up with the spark plug and the bolt hole lines up with the threaded hole.
• Push the coil straight down until it seats fully over the plug; you should feel it bottom out.
• Install the coil bolt by hand using your fingers to avoid cross-threading.
• Tighten the coil bolt with the 8mm socket and inch-pound torque wrench to 8–10 Nm (71–88 in-lbs).

Step 8: Reconnect coil electrical connector

• Slide the electrical connector onto the coil until it clicks.
• Gently pull back to confirm it is locked in place.
• If no click, check the locking tab alignment.

Step 9: Repeat for remaining coils on that bank

• Move to the next coil on the same side and repeat Steps 4–8.
• Always do one coil from start to finish before unplugging the next one.
• Work methodically down the bank so you do not skip any coils.

Step 10: Replace coils on the opposite bank

• Move to the other side of the engine and repeat Steps 4–9 for each coil.
• If any connectors are harder to reach, use your 1/4" drive ratchet with a 1/4" 6" extension and the 8mm socket to access tight spots.
• Confirm all coil bolts are torqued to 8–10 Nm (71–88 in-lbs) and all connectors are clicked in.

Step 11: Reinstall intake duct (if removed)

• Reposition the air intake duct over the throttle body and airbox.
• Make sure it is fully seated on both ends.
• Use the flathead screwdriver to tighten the clamps evenly.
• Torque the intake duct clamps: 3–4 Nm (27–35 in-lbs).

Step 12: Reinstall engine cover

• Align the engine cover grommets with the mounting posts on the engine.
• Press down firmly at each corner until you feel it snap into place.
• Check that the cover is secure and not rattling.

Step 13: Reconnect battery and clear codes (if any)

• Place the negative battery cable back on the negative terminal.
• Use a 10mm socket and foot-pound torque wrench to snug the nut. Do not overtighten.
• Tightening spec for battery terminal: 5–7 Nm (44–62 in-lbs).
• If you have an OBD2 scan tool, plug it in and clear any stored misfire or coil-related codes.

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✅ After Repair

• Start the engine and let it idle for a few minutes. It should run smooth without misfires or shaking.
• Watch the instrument cluster for any check-engine light; if it comes back, scan for codes.
• Gently rev the engine a couple of times while listening for unusual noises around the coils.
• Take a short test drive, checking for smooth acceleration and no hesitation.
• After the drive, shut the engine off, recheck around the coils and intake duct for anything loose.

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💰 DIY vs Shop Cost

Shop Cost: $650–$900 (parts + labor)

DIY Cost: $250–$500 (parts only)

You Save: $400–$400+ by doing it yourself!

Shop labor rates vary but typically run $100–$150/hour. This repair takes a shop approximately 1.5–2.0 hours.

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🎯 Ready to get started?

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