1500 - Thermostat Replacement 🔧

You’re working on a 2015 3.6L V6, which uses a thermostat housing assembly on the front of the engine. I’ll walk you through it step by step.

Safety & Prep ⚠️

• 🧤 Work cold: Let the engine cool at least 1–2 hours; hot coolant can cause serious burns.
• 🔌 Disconnect battery negative: 10 mm wrench on the negative terminal to avoid accidental shorts.
• 🧯 Coolant is toxic: Keep away from kids/pets and dispose of it properly.

Parts You’ll Need 📦

• 🧊 Thermostat & housing assembly (3.6L Pentastar, with seal/gasket included)
• 🧊 Fresh coolant: HOAT / OAT type that meets Chrysler MS-12106 (usually pink/purple; match what’s in your 1500)
• 🧊 Distilled water (if mixing concentrate)
• 🧊 New hose clamp(s) if any are rusty or damaged

Tools Required 🛠️

• 🧰 Socket set:
  • 8 mm, 10 mm, 13 mm sockets (1/4" and 3/8" drive)
  • Short and medium extensions
  • Ratchet
• 🧰 Torque wrench (small, 5–30 Nm / 50–250 in‑lb range)
• 🧰 Flat-blade screwdriver or nut driver (for hose clamps)
• 🧰 Pliers (for spring-type hose clamps)
• 🧰 Drain pan (at least 10 L / 3 gal)
• 🧰 Plastic trim tool (to help with hose removal without cutting)
• 🧰 Shop towels / rags
• 🧰 Funnel (long neck helps)

Hose clamp pliers are special pliers that grip spring clamps securely; regular pliers can work but are more awkward.

Location of the Thermostat 📍

• 🚗 Stand in front of your 1500, hood open.
• Follow the lower radiator hose (big hose from bottom of radiator) back to the engine.
• It connects to an aluminum/plastic thermostat housing on the front of the engine, slightly toward the passenger side.

Coolant Drain (Partial) 💧

• 🪜 Raise the front slightly on ramps or jack stands if needed; always support with stands, never just a jack.
• 🪣 Place the drain pan under the lower radiator hose or radiator drain (petcock).
• 🪣 Easiest: loosen the lower radiator hose clamp at the radiator and crack the hose loose to drain 1–2 gallons.
  • Tip: Only pull the hose off a little so it dribbles instead of dumping everywhere.
• 🪣 Once drained enough, push the hose back on and snug the clamp so it doesn’t leak while you work.

Accessing the Thermostat Housing 🔍

• 🧩 Remove any engine cover:
  • Usually just pulls up off rubber grommets; lift straight up.
• 🧩 If the intake tube is in your way:
  • Loosen the hose clamps at the throttle body and airbox (flat screwdriver or 8 mm socket).
  • Unplug any sensor connectors on the tube (like the intake air temp sensor; press the tab and pull).
  • Lift the tube out and set aside.

Removing the Thermostat Housing 🧊

• 🧊 Place rags under the housing area to catch drips.
• 🧊 Use pliers or screwdriver to loosen the lower radiator hose clamp at the thermostat housing.
• 🧊 Twist the hose gently to break it free, then pull it off the housing.
  • Tip: If it’s stuck, use a plastic trim tool to work around the edge; don’t stab the hose.
• 🧊 Unplug any sensor connector on or near the housing (if equipped).
• 🧊 Remove the thermostat housing bolts:
  • Usually 3 bolts, 10 mm head.
  • Use a 10 mm socket with extension and ratchet.
• 🧊 Carefully pull the housing away from the engine. Some coolant will spill; catch it with the pan.
• 🧊 Remove the old thermostat assembly and gasket/seal (if separate).

Clean the Mating Surface 🧽

• 🧽 Use a clean rag to wipe the engine-side surface where the thermostat sits.
• 🧽 If there’s old gasket material, gently scrape with a plastic scraper.
  • Do not use a metal scraper that can gouge the aluminum.
• 🧽 Make sure no debris falls into the coolant passage.

Install the New Thermostat 🆕

• 🆕 Confirm the new thermostat matches the old one (shape, diameter, housing style).
• 🆕 If the seal/gasket is separate:
  • Fit the new O-ring/gasket into the groove on the thermostat or housing as designed.
• 🆕 Position the thermostat/housing assembly onto the engine:
  • On this engine, the thermostat is usually integrated into the housing; just align the housing with bolt holes.
• 🆕 Install the housing bolts finger-tight first to avoid cross-threading.
• 🆕 Torque the bolts evenly in a criss-cross pattern:
  • Thermostat housing bolts: 10 Nm (89 in‑lb)
  • Snug, not gorilla tight—this is aluminum.
• 🆕 Reinstall the lower radiator hose onto the housing and tighten the clamp securely.
• 🆕 Reconnect any sensor connectors you unplugged.

Reinstall Intake & Covers 🧩

• 🧩 Refit the intake tube:
  • Slide onto throttle body and airbox.
  • Tighten hose clamps (snug with screwdriver or 8 mm socket).
  • Reconnect any sensors.
• 🧩 Push the engine cover back onto its mounting grommets.

Refill & Bleed the Cooling System 🌡️

• 🌡️ Make sure the lower hose at the radiator is fully reattached and clamped.
• 🌡️ Open the coolant reservoir cap.
• 🌡️ Mix coolant if needed:
  • 50/50 mix coolant and distilled water unless you bought premix.
• 🌡️ Slowly fill the reservoir to the “MAX” line.
• 🌡️ On many 3.6L setups there is a bleeder screw on the upper hose or near the thermostat housing:
  • If present, crack it open with the correct socket or screwdriver.
  • Fill until coolant (no bubbles) comes out, then close the bleeder.
• 🌡️ Reconnect the battery negative terminal (10 mm).
• 🌡️ Start the engine and let it idle with the heater set to HOT and fan on low.
• 🌡️ Watch the coolant level in the reservoir:
  • Add as needed to keep it near MAX while air burps out.
• 🌡️ Let the engine reach operating temperature:
  • Upper radiator hose should get hot once the thermostat opens.
  • Cabin heater should blow hot air.
• 🌡️ Check for leaks around the thermostat housing and hose connections.
• 🌡️ Shut off engine, let it cool completely, then recheck coolant level and top off if needed.

Final Checks ✅

• ✅ No coolant drips under the front of the truck after a drive.
• ✅ Temperature gauge stays in the normal middle range.
• ✅ Heater works properly and no “gurgling” sounds from the dash (sign of trapped air).

Shop vs DIY Cost 💰

• 💰 A shop would typically charge:
  • Labor: 1.5–2.0 hours
  • Parts & coolant: often $150–250
  • Total: roughly $300–450 at the higher end.
• 💰 Doing it yourself mainly costs the thermostat assembly, coolant, and basic tools.

If you tell me whether you see a bleeder screw on your upper hose or near the thermostat housing, I can give you a very short, specific bleeding sequence for your exact setup.

HowToo makes it easy: below this answer you’ll see recommended thermostats, coolant, and tools that fit your 1500. You can add them straight to your cart from the parts section for fast shipping.