Thermostat M271 for Mercedes-Benz

OE spec engine thermostat assembly, engineered for Mercedes Benz vehicles with the M271 1.8L petrol engine, Kompressor or CGI turbo. Restores correct warm up time and stable operating temperature, protects against overheating and poor heater performance. Sold per unit, variant specific as supplied with housing and sensor where applicable.

What this is / isn’t:
Included: 1× thermostat assembly

Important: Match by VIN and engine code M271. Early Kompressor and later CGI direct-injection versions can use different housings, outlet angles and connectors. Always confirm by OE part number.

Key Features:

• Precise temperature control: OE matched opening temp and flow for stable engine and cabin heat.

• Integrated housing and seal: Direct bolt on replacement to minimise leaks and comeback repairs.

• Correct sensor or actuator logic: Works with the ECU for accurate warm up and efficiency.

• Durable materials: High temp plastics and elastomers resist glycol and heat cycling.

• Exact fitment: Factory mounting points for a no mod install.

Compatibility:
Common applications equipped with the M271 four cylinder, match by VIN or OE:

• C Class W203, W204 C180, C200, C230K, C200 CGI, C250 CGI

• E Class W211, early W212 E200K, E200 CGI

• CLK C209, A209 200K trims

• SLK R171, early R172 200K and 200 CGI

• GLK X204 200 CGI where fitted
  Note: Some markets vary by year and emissions package, verify via VIN.

Options, engine or sensor variations:

• M271 Kompressor → thermostat with specific housing orientation.

• M271 EVO or CGI → revised housing and connector, check supersessions.

• Model year revisions → later updates may change outlet and sensor style.

Typical OE reference families, guide only:
A271-200-…, A271-203-…, supersessions vary by year and market.
Always order by the exact OE part number on your vehicle or confirm via VIN.

Symptoms of a faulty thermostat:

• Slow warm up, temperature gauge low or fluctuating.

• Overheating at idle or in traffic.

• Weak cabin heat, fault code P0128 or similar temperature errors.

• Coolant seepage at housing, dried crust around joints.

Installation notes, pro tips:

• Work on a cold engine. Drain coolant to below the housing level.

• Replace the seal or O ring, clean mating faces, torque bolts evenly to spec.

• Refill with Mercedes approved coolant, MB 325.x spec, bleed the system thoroughly.

• Verify fan operation and hose temperatures on first heat cycle, clear stored codes after a road test.

• Inspect adjacent hoses, clamps and plastic tees for age related brittleness.

What’s included / not included:
✅ 1× Thermostat assembly with housing and seal, sensor or actuator if supplied
❌ Coolant, hoses, clamps, water pump, radiator, extra sensors, hardware

Q&A
Q1: How do I confirm I have the M271 engine?
Check the VIN data card or engine stamp. M271 appears in many C, E, CLK, SLK and GLK models. Your VIN will map to the exact part number.
Q2: Do I need coding after replacement?
No coding is usually required. Clear fault codes and verify operating temperature with a scan tool.
Q3: Which coolant should I use?
Mercedes coolant meeting MB 325.x specification, mixed to the correct ratio for your climate.
Q4: Should I change anything else at the same time?
Consider a coolant service, inspect hoses and clamps, and replace brittle plastic fittings.

Why choose TOParts:
OE grade engine components for Mercedes Benz with precise fitment, correct specs and long term reliability, trusted by panel shops and independent Mercedes specialists across South Africa.