How to Replace the Head Gaskets on a 2014 Dodge Challenger SXT (3.6L Pentastar Engine)

Introduction

Replacing the head gaskets on the 3.6L Pentastar engine is a complex job requiring patience and precision. Symptoms of a failed head gasket include coolant loss, overheating, white exhaust smoke, and misfires. This guide will walk you through the general process steps. I would recommend locating a service manual for more detailed torque specs and sequences needed for this job. You can also find diagrams and specs online as well.

Estimated Time & Difficulty

⏳ Time Required: 10–15 hours
🔧 Difficulty: Advanced (Requires engine disassembly)

Tools & Parts Needed

Tools

• Torque wrench (capable of angle torquing)
• Socket set (metric)
• Breaker bar
• Fuel line disconnect tool
• Gasket scraper & razor blade
• Cooling system pressure tester
• RTV sealant (for timing cover)
• Timing chain replacement tool kit for removal and alignments

Replacement Parts

• MLS (Multi-Layer Steel) Head Gasket Set
• New head bolts (torque-to-yield, single-use)
• Intake and exhaust manifold gaskets
• Coolant, oil, and filter
• Thermostat & water pump (recommended)
• Timing chain kit (if worn or high mileage)

Majority of the parts and the Timing chain tool kit I sourced from Amazon

Disassembly Process

Its very important to keep your work area clean and organized. Its also really helpful if you have a large work table to lay everything out in some sort of order to make the install easier. Taking pictures of the disassembly will make the re-assembly much smoother.

Step 1 – Disconnect Battery & Drain Fluids

• Disconnect the negative battery terminal.
• Drain the coolant from the radiator and engine block.
• Drain the engine oil to remove the lower oil pan in order to remove the timing cover.
• label, list or take pictures of the wire harness routing for an easier install.
• Unplug and set aside the wiring harness out of the way.

Step 2 – Remove Air Intake & Fuel System

• Remove the air intake, throttle body, and upper intake manifold.
• Depressurize and disconnect the fuel rail and injectors.
• Remove the lower intake manifold and cover the intake ports.

Step 3 – Remove Exhaust Manifolds

• Unbolt both exhaust manifolds and set aside.

Step 4 – Remove Cylinder Heads

• Remove valve covers, timing cover, and timing chain tensioner.
• In order to remove the timing cover you must access the 4 lower timing cover bolts located inside of the oil pan.
• Unbolt camshafts and mark positions for reinstallation.
• Remove cylinder head bolts in reverse torque sequence and lift heads.
• the alternator and AC compressor just need to be un bolted and pushed to the sides.

Cylinder Head Bolt Removal Sequence

(Follow in reverse order for loosening; refer to reinstallation steps for correct order.)

Passenger Side (Right Head):

1. 10 6 2
2. 9 5 1
3. 8 4 3
4. 7

Driver Side (Left Head):

1. 1 5 9
2. 2 6 10
3. 3 7 8
4. 4

Tip: There are lots of diagrams online showing the correct sequence.

Cleaning & Inspection

Step 5 – Surface Preparation

• Inspect heads for warping using a straightedge and feeler gauge.
• If warping exceeds 0.003 inches, resurface the heads professionally.
• Use a gasket scraper to remove old gasket material.
• Ensure bolt holes are clean to prevent false torque readings.

Tip: In a pinch lacking the funds or time? If you can’t get the heads resurfaced professionally you can use a flat surface or large flat sanding block, sand paper, WD40 and some elbow grease. I used this DIY method with success on my build. There are lots of videos demonstrating this method. If your heads are just too warped for this method then new heads or a machine shop is your only choice.

Reinstallation Process

Step 6 – Install New Head Gaskets

• Place new MLS head gaskets (ensure correct orientation).
• Align dowel pins and carefully place cylinder heads.

Step 7 – Torque Cylinder Head Bolts

• New bolts are required (torque-to-yield, cannot be reused).

Head Bolt Torque Specs & Sequence

Torque Sequence (Tighten in order for BOTH heads):

1. 1 5 9
2. 2 6 10
3. 3 7 8
4. 4

Torque Stages:

1. Initial Pass: 30 ft-lbs
2. Second Pass: 60 ft-lbs
3. Final Pass: 90° Turn (torque-to-yield)

Tip: There are lots of diagrams online showing the correct sequence.

Timing Chain Reinstallation

Step 8 – Set Timing Marks & Install Chain

• Align the timing marks on camshaft gears with colored links on the chain.
• Ensure crankshaft timing mark is aligned at TDC (Top Dead Center).
• Install the timing chain tensioner and manually rotate the crankshaft two full revolutions to verify timing.

Timing Chain Torque Specs

• Camshaft sprocket bolts: 105 ft-lbs
• Timing cover bolts: 18 ft-lbs

Water Pump:

Tighten the bolts 1 – 12 in the sequence shown. Tighten the bolts to their respective torque:
•M6 mounting bolts to 12 N·m (9 ft. lbs.).
•M8 bolts to 25 N·m (18 ft. lbs.).
•M10 bolt to 55 N·m (41 ft. lbs.).
•Now repeat the tightening sequence until the proper torque has been met.

The bolts vary in length, the four bolts that that bolt directly to the cover are different.

Final Assembly & Testing

Step 9 – Reassemble Components

Reinstall:

• Exhaust manifolds (torque bolts to 25 ft-lbs)
• Lower intake: (106 in-lbs)
• Fuel system and Upper intake manifold (torque bolts to 89 in-lbs)
• Throttle body and air intake

Step 10 – Refill Fluids & First Start

• Refill coolant and engine oil.
• Start engine and check for leaks.
• Let engine reach operating temperature and recheck for coolant loss or misfires.

Final Checks & Test Drive

• Compression Test (each cylinder should read 150+ psi)
• Check for leaks (coolant, oil, vacuum)
• Monitor for overheating during first 30 minutes of run time

FAQs & Troubleshooting

Do I need to resurface the heads?

• Yes, if warping is more than 0.003 inches.

What happens if I don’t follow the correct torque sequence?

• Uneven clamping pressure can cause leaks and premature failure.

Can I reuse the timing chain?

• If your engine has over 100k miles, it’s best to replace it.

Final Thoughts & Next Steps

Replacing the head gaskets on a 3.6L Pentastar is a big job, but following this guide carefully will help ensure a successful repair. If you have any questions, drop them in the comments below