Parts for your 2013 Nissan Serena-Thermostat

2013 Nissan Serena Thermostat — Purpose, Maintenance, and Replacement

For the 2013 Nissan Serena (C26 series, MR20DE petrol and S-HYBRID variants), a conventional engine coolant thermostat is absolutely fitted and relevant. Technical sources that list this component include the Nissan Serena C26 Service Manual (Cooling System/CO section), the Nissan FAST electronic parts catalogue (Thermostat Assembly for MR20DE), and MR20DE engine documentation outlining a wax-pellet thermostat that begins opening in the low 80s °C and is fully open by the low 90s °C.

The thermostat’s job is to help the engine warm up quickly and then hold it at its ideal operating temperature. It stays closed on a cold start to keep coolant within the engine, speeding warm-up and reducing wear and fuel use. As temperature rises, it opens to route coolant through the radiator and keep temps stable under load, towing, or stop–start city runs. On the Serena’s MR20DE, the thermostat sits at the engine-side water inlet, typically where the lower radiator hose meets the block.

While thermostats aren’t usually a scheduled replacement item, they’re central to the cooling system’s health. During servicing, owners should ensure coolant is replaced at the intervals recommended by Nissan, inspect for leaks around the housing, and confirm stable gauge behaviour on a test drive. If the thermostat is aged, sticking, or the engine shows slow warm-up or creeping temps, it’s smart preventative maintenance to replace it along with the O-ring/gasket.

• Common signs it needs attention: overheating under load, poor heater performance, erratic temperature gauge, radiator fans running excessively, or unusually low fuel economy.
• Best practice during replacement: use a quality OEM-spec thermostat, renew the seal, refill with Nissan Blue long-life coolant (or equivalent silicate-free LL coolant), and bleed the system properly to avoid air pockets.

A competent workshop will usually allow around 1–2 hours for the job. It’s also a good time to check hose condition, radiator cap integrity, and water pump weep holes. Avoid mixing coolant colours and always use demineralised water if a concentrate is used. Keeping the thermostat and coolant in top nick helps the Serena maintain smooth drivability, heater performance, and engine longevity on long Kiwi or Aussie road trips.

Popular questions about the 2013 Nissan Serena thermostat

1) What are the symptoms of a failing thermostat on a 2013 Serena?
Typical signs include the temperature gauge rising higher than normal, slow cabin heat on cold mornings, fans running constantly, or the gauge dropping on the highway then spiking in traffic. Any coolant loss, milky deposits, or rusty residue around the housing also warrant inspection.

2) Where is the thermostat located and how hard is it to replace?
On the MR20DE it’s mounted at the engine water inlet, near the lower radiator hose at the block. Access is moderate on the Serena: the housing is reachable from above with basic hand tools, though space is tighter on some trims. Expect draining some coolant, swapping the unit and seal, then a careful bleed to remove air.

3) Do owners need genuine Nissan parts and coolant?
Genuine or OEM-equivalent thermostats with the correct temperature rating are recommended. For coolant, use Nissan Blue long-life coolant or an equivalent high-quality, silicate-free LL coolant that meets Nissan specs. Mixing coolants is a no-go, stick with one type and flush if changing.