THERMOSTAT

Engine Coolant Regulator for Mercedes A‑Class 🚗

This OEM‑grade coolant control unit keeps your engine at the right temperature. It helps the motor warm up fast, stay stable under load, and protect oil, gaskets, and sensors. Correct heat management improves fuel economy, cuts emissions, and makes the cabin heater work better.

Why you need it 🔧

Engines are designed to run in a narrow heat range. If coolant flow is wrong, you get poor performance, higher fuel use, and early wear. This part is essential for reliability in city traffic and highway drives.

How it works 🧠

Inside is a wax‑pellet actuator and spring. When coolant is cold, the valve stays shut, bypassing the radiator for quick warm‑up. Near operating temp (about 85–95°C),the wax expands, pushing the valve open to route coolant through the radiator, keeping temperature steady.

What happens if it fails ⚠️

Stuck closed: overheating, boiling coolant, warning light, risk of warped head or blown gasket. Stuck open: slow warm‑up, rich mixture, higher fuel burn, weak heater, possible code P0128. Leaks at the housing cause low coolant and air pockets.

Pro tips for replacement 🛠️

Always install a new seal/O‑ring, use the correct MB‑spec coolant, bleed air, and torque the housing evenly. Check hoses and the sensor. Clear fault codes after service.

• A 200
• A 180
• A 160