Parts for your 2010 Nissan Serena-Thermostat

2010 Nissan Serena Thermostat: purpose, care, and when to replace

Based on Nissan technical sources — including the factory service manuals (C25/C26 Serena) and Nissan parts catalogues for the MR20DE petrol and M9R diesel engines — the 2010 Nissan Serena is fitted with a conventional wax‑pellet engine coolant thermostat. It’s a core part of the cooling system and absolutely relevant to this model.

The thermostat’s job is simple but critical: it holds coolant in the engine while it warms up, then meters flow to the radiator to keep temperature steady. On Serena engines of this era, the thermostat typically begins to open around 82–88°C, helping the engine reach operating temperature quickly for smoother running, better fuel economy, effective cabin heat, and lower emissions. At cruising speed or in stop–start traffic, it continually trims flow so the gauge stays bang in the middle.

When a thermostat fails, it usually does one of two things. Stuck closed, the Serena can overheat quickly — not ideal on a summer run up the motorway. Stuck open, it takes ages to warm, the heater’s weak, and fuel use can creep up