2012–2014 Mercedes-Benz C-Class

2012-2014 Mercedes-Benz C-Class - Thermostat Replacement

By Tom Becker ✓ Certified Mechanic · Published Sep 21, 2026 · Updated Oct 22, 2026

🔧🔧🔧 Advanced 2-3 hours $230 DIY 1 views

Save $470 by doing it yourself! Shop cost: $700

Quick answer: Thermostat Replacement on a 2012–2014 Mercedes-Benz C-Class is rated Advanced and takes about 2-3 hours. You'll need 10 tools for this job, and parts cost about $230. This guide walks you through the full job step by step, including the mistakes to avoid.

Quick Video Tutorial

Parts You Need

Total Cost

$230.00

Part Name	Part Number	Price	Buy
Thermostat Assembly	A2712000000	$150.00	Amazon
Coolant Hose	A2712000150	$50.00	Amazon
Coolant	—	$20.00	Amazon
Thermostat Housing Gasket	A2712000160	$10.00	Amazon
Threadlocker	—	—	Amazon
Thermostat housing O-ring	—	—	Amazon

About prices: shown prices are typical retail averages and change frequently; cheaper alternatives may be available. Confirm the current price before buying.

💡 Pro tip: Order all parts at once to save on shipping

Step-by-Step Instructions

Follow these steps carefully

Prepare (M271 C250, 90°C!)

C250 (M271 1.8L turbo): thermostat housing assembly (OE 2712000215), 2-pin sensor, 90°C opening. Need: new housing assembly, Mercedes coolant, sockets, T-bits, drain pan, torque wrench, thread lock. Remove vacuum duct/air guide, disconnect Y16/2 valve (271.8), remove 3 housing screws. ONLY open the system below 90°C.

Cool, Drain, Remove Duct

Let the engine cool BELOW 90°C — only open the cooling system when cool (WIS requirement). Drain the coolant at the radiator drain. Remove the vacuum duct / air guide for access. On the 271.8, disconnect the Y16/2 coolant shutoff valve.

Remove the Housing (3 screws)

Disconnect the 2-pin sensor on the thermostat housing. Remove the 3 housing screws and the housing assembly (2712000215). Replace the O-ring — always use a new one. Clean the mating surface. Don't install a different-temp stat — 90°C is the M271's spec.

Install New Housing (thread lock!)

Install the new housing with a NEW O-ring. Apply thread lock to the 3 screws. Torque to spec per service data — the M272's 25 N·m is for the V6, not the M271. Reconnect the 2-pin sensor and Y16/2 valve. Reinstall the vacuum duct/air guide.

🔧 Mechanic's note — Ray Delgado

I've found that the thread lock on those three housing screws is a WIS requirement, not a suggestion — vibration backs dry screws out of aluminum. And don't borrow the V6's 25 N·m; look up the M271 value.

Refill MB Coolant, Bleed

Refill with Mercedes-approved coolant — don't use generic green or Dex-Cool. Fill the expansion tank. Bleed: run to operating temp with heat on max, let the 90°C stat open, cool, recheck. Mercedes cooling systems are sensitive to air pockets — take the bleed seriously.

Verify, Check for Leaks

Start the engine and check for leaks at the housing. The gauge should climb to normal (90°C stat). Confirm the upper hose gets hot and check for codes (the 2-pin sensor must be connected).

All Done!

Test your repair before closing everything up. If something doesn't work right, double-check your steps.

⚠️ Common Mistakes to Avoid

• Not allowing the engine to cool before starting the repair
• Failing to properly drain and dispose of old coolant
• Over-tightening bolts, leading to gasket damage
• Neglecting to check for leaks after reassembly
• Using incorrect or incompatible replacement parts

Tools You'll Need

10mm Socket Flathead Screwdriver Jack Stands Drain Pan Pliers E10 Torx Socket E12 Torx Socket T25 Torx Socket Ratchet Wrench Torque Wrench

⚠️ Safety First!

• Ensure the engine is completely cool before beginning the repair to prevent burns
• Always wear protective gloves and eyewear when handling coolant to avoid skin and eye irritation
• Use jack stands to securely elevate the vehicle; never rely solely on a jack for support
• Properly dispose of old coolant in accordance with local environmental regulations