Remove and replace the exhaust manifold(s) on a 2012-2018 Jeep Wrangler 3.6L V6, including heat shields, oxygen sensors, and gasket replacement.

Warnings

Tools required

Parts

• Exhaust manifold gasket (left or right) × 1 — Use OEM specification
• Exhaust manifold nuts × 8 — OEM replacement recommended
• Heat shield (if damaged) × 1 — Use OEM specification
• Oxygen sensor (if damaged) × 1 — Use OEM specification
• EGR tube gasket (if equipped) × 1 — Use OEM specification
• Anti-seize compound × 1 — High temperature rated
• Exhaust flange gasket × 1 — Use OEM specification

Preparation

1. Ensure engine is completely cold to the touch
2. Disconnect negative battery cable
3. Raise and support vehicle securely on jack stands
4. Spray all exhaust manifold nuts, oxygen sensor(s), and flange bolts with penetrating oil and allow to soak (overnight preferred)
5. Remove engine cover if equipped
6. Identify which manifold requires replacement (driver side/left or passenger side/right)

Procedure

1. 1

   Remove heat shield
   Locate and remove the heat shield bolts securing the shield to the exhaust manifold. The 3.6L uses multiple heat shields. Remove the shield and set aside. Inspect for damage or excessive corrosion.
   Torque spec

   Heat Shield Bolts15 Nm (11 lb-ft)
2. 2

   Disconnect oxygen sensor(s)
   Locate the oxygen sensor(s) on the manifold being replaced. Disconnect the electrical connector by pressing the release tab. Use an oxygen sensor socket to remove the sensor from the manifold. Turn counterclockwise while supporting the wiring harness to prevent damage. Inspect sensor condition.
   ⚠Do not allow oxygen sensor to hang by wiring harness. Support the sensor to prevent wire damage.
   Torque spec

   O2 Sensor52 Nm (38 lb-ft)
3. 3

   Disconnect EGR tube (if equipped)
   If working on the passenger side manifold and vehicle is equipped with EGR, disconnect the EGR tube from the manifold. Remove the tube fitting and any mounting bolts. Move the tube aside to provide clearance.
   Torque spec

   EGR Tube Fitting52 Nm (38 lb-ft)
4. 4

   Disconnect exhaust pipe from manifold
   From underneath the vehicle, locate the exhaust flange connection where the exhaust pipe meets the manifold. Remove the flange bolts securing the pipe to the manifold. Support the exhaust pipe to prevent stress on hangers. Separate the connection and remove the old gasket.
   ⚠Flange bolts are highly susceptible to corrosion. Use heat if necessary but avoid damaging surrounding components.
   Torque spec

   Flange Bolts55 Nm (40 lb-ft)
5. 5

   Remove exhaust manifold mounting nuts
   Working from the engine bay, remove all exhaust manifold nuts securing the manifold to the cylinder head. The 3.6L has 8 nuts per manifold. Work from the center outward in a crisscross pattern to prevent warping. Note any studs that pull out with the nuts.
   ⚠If studs break or pull from cylinder head, use a stud extractor or drill out carefully. Do not force removal if excessive resistance is encountered.
   Torque spec

   Exhaust Manifold Nuts38 Nm (28 lb-ft)
6. 6

   Remove exhaust manifold
   Carefully remove the exhaust manifold from the cylinder head. May require wiggling and slight twisting to clear studs and surrounding components. Passenger side requires maneuvering around steering components; driver side may require removing engine mount hardware for clearance. Remove and discard the old manifold gasket.
7. 7

   Clean mating surfaces
   Use a plastic gasket scraper to carefully remove all old gasket material from the cylinder head mating surface. Do not use metal scrapers that could gouge the aluminum head. Clean the surface with brake cleaner and inspect for cracks or damage. Ensure surface is completely clean and dry.
   ⚠Aluminum cylinder heads are easily damaged. Use only plastic scrapers and avoid aggressive scraping that could create leaks.
   Torque spec

   Gasket Surface Bolts23 Nm (17 lb-ft)
8. 8

   Inspect studs and replace if necessary
   Inspect all exhaust manifold studs in the cylinder head. If any are damaged, stripped, or pulled out during removal, they must be replaced. Use proper thread chaser to clean threads if studs are intact. Apply anti-seize to stud threads sparingly.
9. 9

   Install new manifold gasket
   Position the new exhaust manifold gasket onto the cylinder head studs. Ensure gasket is properly oriented with any alignment tabs or markings facing the correct direction. Gasket should sit flush against the head surface.
10. 10

    Install exhaust manifold
    Carefully position the new or cleaned exhaust manifold onto the studs and gasket. Ensure manifold seats evenly on the gasket. Thread on new exhaust manifold nuts finger-tight on all studs before tightening any. Apply a small amount of anti-seize to nut threads.
    ℹ️Use new nuts if possible. Old nuts may have damaged threads or reduced clamping force.
    Torque spec

    Exhaust Manifold Nuts38 Nm (28 lb-ft)
11. 11

    Torque manifold nuts to specification
    Using a torque wrench, tighten the exhaust manifold nuts to 38 Nm (28 lb-ft) in a crisscross pattern starting from the center and working outward. Make multiple passes, first to 50% torque, then to final specification to ensure even clamping pressure.
    Torque spec

    Exhaust Manifold Nuts38 Nm (28 lb-ft)
12. 12

    Reconnect exhaust pipe to manifold
    Install new exhaust flange gasket between the manifold and exhaust pipe. Align the pipe to the manifold flange and install flange bolts. Apply anti-seize to bolt threads. Torque flange bolts to 55 Nm (40 lb-ft) in a crisscross pattern.
    Torque spec

    Flange Bolts55 Nm (40 lb-ft)
13. 13

    Reinstall EGR tube (if equipped)
    If removed, reconnect the EGR tube to the manifold using a new gasket. Torque the EGR tube fitting to 52 Nm (38 lb-ft). Ensure tube is properly routed and not contacting other components.
    Torque spec

    EGR Tube Fitting52 Nm (38 lb-ft)
14. 14

    Install oxygen sensor(s)
    Apply a thin coat of anti-seize compound to the oxygen sensor threads (avoid getting anti-seize on the sensor tip). Thread the sensor into the manifold by hand, then use the oxygen sensor socket to torque to 52 Nm (38 lb-ft). Reconnect the electrical connector ensuring it clicks into place.
    ⚠Never apply anti-seize to oxygen sensor tip or contamination will cause sensor failure and check engine light.
    Torque spec

    O2 Sensor52 Nm (38 lb-ft)
15. 15

    Reinstall heat shield
    Position the heat shield over the manifold and install heat shield bolts. Torque bolts to 15 Nm (11 lb-ft). Ensure shield is properly seated and not contacting moving components.
    Torque spec

    Heat Shield Bolts15 Nm (11 lb-ft)

Reassembly

1. Reinstall engine cover if removed
2. Reconnect negative battery cable
3. Lower vehicle from jack stands
4. Double-check all fasteners are tight and no tools were left in engine bay

Verification

• Start engine and allow to idle. Listen for any exhaust leaks at manifold and flange connections
• Check for abnormal noises, vibrations, or exhaust odors from engine bay
• Allow engine to reach operating temperature and verify no leaks develop
• Check for check engine light. If illuminated, scan for oxygen sensor or exhaust system codes
• Perform a test drive and verify normal engine operation and no exhaust smell in cabin
• After first heat cycle, re-check torque on manifold nuts and flange bolts (optional but recommended)

More procedures for this vehicle