Exhaust Manifold Gasket

This procedure covers the removal and replacement of exhaust manifold gaskets on the 3.6L V6 Pentastar engine, including oxygen sensor removal and proper torque sequence.

Warnings

Tools required

Parts

• Exhaust manifold gasket set (left and right) × 1 — Use OEM specification
• Exhaust manifold bolts (if corroded) × 1 — Use OEM specification

Preparation

1. Ensure engine is completely cold
2. Disconnect negative battery terminal
3. Raise and support vehicle safely on jack stands
4. Spray all exhaust fasteners with penetrating oil and allow to soak
5. Remove engine cover by pulling upward on retention clips
6. Remove skid plate if equipped (4 bolts)
7. Identify which manifold requires service (this procedure covers one side)

Procedure

1. 1

   Remove heat shields
   Remove the heat shield covering the exhaust manifold by removing the retaining bolts. There are typically 3-4 bolts securing each shield. Set shield aside.
2. 2

   Disconnect oxygen sensors
   Locate the upstream and downstream oxygen sensors on the manifold and exhaust pipe. Disconnect the electrical connectors by pressing the release tab. Using an oxygen sensor socket or 22mm wrench, carefully remove both O2 sensors. Turn counterclockwise. If sensors are seized, apply more penetrating oil and allow to soak.
   ⚠Oxygen sensor wires are fragile. Do not pull on wires when removing sensors.
3. 3

   Remove exhaust flange connection
   From underneath the vehicle, locate the exhaust pipe flange connection at the manifold outlet. Remove the two flange bolts and separate the exhaust pipe from the manifold. You may need to support the exhaust pipe with a stand or wire to prevent strain on downstream hangers.
   ⚠Flange bolts are often severely corroded. Use a breaker bar and be prepared for possible bolt breakage.
4. 4

   Disconnect electrical connections
   If working on the right side (passenger), disconnect the engine wiring harness connectors that may interfere with manifold removal. Remove any electrical connector mounting bolts as needed. Note the routing for reinstallation.
5. 5

   Remove exhaust manifold mounting bolts
   Remove all exhaust manifold mounting bolts. The 3.6L V6 has 8 bolts per manifold in a specific pattern. Start from the center and work outward, removing bolts evenly. Keep track of bolt locations as some may be different lengths.
   ⚠If a bolt breaks, stop and use a bolt extractor. Do not attempt to remove manifold with broken bolts remaining.
6. 6

   Remove exhaust manifold
   Carefully remove the exhaust manifold from the cylinder head. It may be stuck due to carbon buildup. Gently rock the manifold to break it free. Do not pry against the cylinder head sealing surface.
7. 7

   Remove old gasket and clean surfaces
   Remove the old exhaust manifold gasket from the cylinder head. Use a plastic or brass gasket scraper to carefully clean all gasket material from both the cylinder head and manifold mating surfaces. Follow with brake cleaner to remove all oil and debris. Surfaces must be completely clean and flat for proper sealing.
   ⚠Do not use metal scrapers on aluminum cylinder head surfaces as this can cause gouging and leaks.
8. 8

   Inspect manifold and cylinder head
   Inspect the exhaust manifold for cracks, especially around bolt holes and runners. Check cylinder head surface for warping or damage. Replace manifold if cracked. If head surface is damaged, cylinder head resurfacing may be required.
9. 9

   Install new gasket and position manifold
   Position the new exhaust manifold gasket on the cylinder head studs or alignment pins. Carefully position the exhaust manifold onto the gasket, ensuring proper alignment with all bolt holes. Do not use gasket sealant unless specified by gasket manufacturer.
10. 10

    Install and torque manifold bolts
    Install all exhaust manifold mounting bolts finger-tight. Starting from the center bolts and working outward in a crisscross pattern, torque all bolts to specification in at least two stages: first to 12 Nm (9 lb-ft), then to final torque of 54 Nm (40 lb-ft). Follow a proper torque sequence from center outward.
    ⚠Use proper torque sequence to prevent manifold warping. Do not skip the multi-stage torque process.
11. 11

    Reconnect exhaust flange
    Position the exhaust pipe to the manifold flange. Install new flange gasket if equipped. Apply anti-seize compound to the flange bolt threads. Install and torque flange bolts to 55 Nm (40 lb-ft).
12. 12

    Reinstall oxygen sensors
    Apply anti-seize compound to the threads of both oxygen sensors (avoid getting compound on the sensor tip). Install upstream and downstream O2 sensors and torque to 55 Nm (40 lb-ft). Reconnect electrical connectors ensuring they click into place.
13. 13

    Reinstall heat shields and components
    Reinstall the exhaust manifold heat shield and torque mounting bolts. Reconnect any electrical connectors and harness brackets removed during disassembly. Reinstall engine cover and skid plate if equipped.

Reassembly

1. Reconnect negative battery terminal
2. Lower vehicle from jack stands
3. Double-check all connections and fasteners are secure
4. Ensure no tools or parts are left in engine compartment

Verification

• Start engine and allow to idle. Listen for any exhaust leaks at the manifold gasket area
• Check for exhaust odors or visible exhaust gases escaping from gasket area
• Allow engine to reach operating temperature and verify no leaks occur when hot
• Check that all oxygen sensor codes are cleared and sensors are functioning properly
• Perform a test drive and verify no exhaust noise or smell enters cabin
• Re-check manifold bolt torque after first heat cycle if desired

Related trouble codes on this vehicle

Codes that commonly send this job to the bay — tap one for symptoms, causes, and diagnostic steps.

Chasing one of these codes and not sure which part is guilty? Ask a master mechanic about YOUR car →

More procedures for this vehicle