🔧 Charger - Thermostat Replacement

The thermostat controls coolant flow to keep your A4—sorry, your Charger—at the correct operating temperature. If it’s stuck open you’ll run cool (poor heat, worse fuel economy); stuck closed can cause overheating. On your Charger, the thermostat sits at the front of the engine where the upper radiator hose connects.

Difficulty Level: Intermediate | Estimated Time: 1.5–3.0 hours

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⚠️ Safety & Precautions

• 🛑 Never open the coolant cap when hot; burns risk.
• 🧤 Wear gloves and safety glasses; coolant is toxic and slippery.
• 🌡️ Work only on a fully cool engine (ideally sitting 2+ hours).
• 🧼 Clean spills immediately; keep coolant away from kids/pets.
• 🔋 Battery disconnect is not required for this job.

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🔧 Required Tools

You'll need the following tools for this repair:

• Safety glasses
• Nitrile gloves
• Drain pan (at least 10-quart)
• Funnel
• Shop towels
• Ratchet
• Socket extension 3"
• 8mm socket
• 10mm socket
• Hose clamp pliers
• Flathead screwdriver
• Torque wrench (in-lb)
• Trim clip tool
• Floor jack (rated 3-ton minimum)
• Jack stands (rated 3-ton minimum)
• Wheel chocks

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Engine thermostat (5.7L specific) - Qty: 1
• Thermostat seal / O-ring - Qty: 1
• Engine coolant (OAT, 50/50 premix) - Qty: 2–3 gallons

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📋 Before You Begin

• Park on level ground, set the parking brake, and install wheel chocks.
• Let the engine cool completely.
• Set the cabin HVAC to HOT (this helps coolant flow through the heater circuit during bleed).
• If you need more access underneath, lift the front with a floor jack and support with jack stands on proper lift points.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Relieve cooling-system pressure (cold engine only)

• Place a shop towel over the coolant reservoir cap.
• Slowly loosen the cap by hand to release any leftover pressure, then remove it.

Step 2: Drain enough coolant to drop the level below the thermostat

• Position a drain pan under the radiator drain area.
• If equipped with a drain petcock, open it carefully using a flathead screwdriver (some turn by hand) and drain 1–2 gallons.
• If you can’t access the drain easily, you can drain from the lower radiator hose instead, using hose clamp pliers and a drain pan.
• Tip: Drain only what you need to reduce mess.

Step 3: Remove the intake duct for working room

• Loosen the intake clamps using an 8mm socket or flathead screwdriver.
• Unclip/remove any snorkel or cover fasteners using a trim clip tool.
• Lift the intake ducting out of the way.

Step 4: Remove the upper radiator hose from the thermostat housing

• Follow the upper radiator hose to the front of the engine (thermostat housing area).
• Compress the hose clamp using hose clamp pliers, then slide the clamp back on the hose.
• Twist the hose to break it free, then pull it off the housing. Keep the drain pan underneath for spills.

Step 5: Remove the thermostat housing

• Remove the thermostat housing bolts using a 10mm socket, ratchet, and 3" extension.
• Carefully separate the housing and remove the thermostat.
• Remove the old seal/O-ring and wipe the sealing surfaces clean using shop towels.
• Tip: Don’t gouge the aluminum sealing surface.

Step 6: Install the new thermostat and seal

• Install the new thermostat seal / O-ring onto the new thermostat (or into the housing groove, depending on design).
• Set the new thermostat in place in the same orientation as the old one.
• Reinstall the housing and start all bolts by hand to avoid cross-threading.
• Tighten evenly with a 10mm socket.
• Torque to 12 Nm (105 in-lbs) using a torque wrench (in-lb).

Step 7: Reinstall the upper radiator hose

• Push the hose fully onto the housing.
• Move the clamp back into its original position using hose clamp pliers.
• Wipe the area clean with shop towels so leaks are easy to spot.

Step 8: Reinstall the intake duct

• Reinstall the intake ducting and any clips using a trim clip tool.
• Tighten the intake clamps using an 8mm socket or flathead screwdriver.

Step 9: Refill coolant

• Insert a funnel into the coolant reservoir.
• Refill with OAT, 50/50 premix coolant until it reaches the correct level.

Step 10: Bleed air and verify operation

• Start the engine and let it idle with the reservoir cap off for a few minutes (watch for splashing).
• Turn the heater to HOT and fan to medium.
• As the engine warms up, add coolant as the level drops using a funnel.
• Once you feel steady heat from the vents and the upper hose gets hot (thermostat opened), install the reservoir cap.
• Let the engine reach normal temp, then shut it off and inspect for leaks.

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✅ After Repair

• Check for leaks around the thermostat housing and upper hose after the first warm-up.
• After a full cool-down, recheck coolant level and top off if needed.
• Test drive 10–15 minutes and confirm the temperature gauge is stable and heater output is hot.
• Dispose of old coolant properly (most parts stores accept waste coolant).

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💰 DIY vs Shop Cost

Shop Cost: $350–$650 (parts + labor)

DIY Cost: $60–$180 (parts only)

You Save: $170–$590 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.5–3.0 hours.

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🎯 Ready to get started?

HowToo makes it easy: same-day/2-day shipping on every part, plus all the tools and specialty tools you need! Check out the parts and tools sections below to add everything to your cart.