Parts for your 2017 Nissan Pulsar-Thermostat

2017 Nissan Pulsar thermostat: what it does, when to replace it, and how to keep it happy

Technical documentation confirms a thermostat is fitted to the 2017 Nissan Pulsar. The Nissan Pulsar C13/B17 Service Manuals (Cooling System sections) specify a wax‑pellet thermostat controlling coolant flow, and the Nissan Electronic Parts Catalogue lists a thermostat assembly and seal for the MR‑series petrol engines and the HRA2 turbo petrol. So a thermostat is relevant to every 2017 Pulsar variant sold in Australia and New Zealand.

The thermostat’s job is simple but critical: help the engine warm up quickly, then hold it at a stable operating temperature. When cold, it keeps coolant within the block for a faster warm‑up, once near spec temperature (typically low‑80s °C), it opens progressively to the radiator. That stability protects the engine, improves fuel economy, reduces emissions, and keeps the cabin heater consistent on cold mornings.

On a Pulsar that’s taking ages to warm up, running cool on the open road, or overheating in traffic, the thermostat could be sticking open or closed. Erratic gauge movement, weak heater output, a surging cooling fan, or a P0128 diagnostic code are other common clues. Don’t ignore them—prolonged overheating can cook head gaskets, while a cold‑running engine wastes fuel and can foul plugs.

Thermostats aren’t a set‑interval item, but they’re smart to replace whenever there’s a cooling‑system overhaul, major hose/radiator work, or evidence of age. On the 2017 Pulsar, replacement is straightforward for a competent home mechanic: drain enough coolant to drop the level below the housing, remove the housing, swap the thermostat and new O‑ring, then refill and bleed. Use the correct Nissan long‑life coolant premix, torque the housing bolts evenly, and bleed air thoroughly to avoid hot spots. Afterward, verify heater performance, confirm the radiator hoses warm in the right order, and check for leaks over the next few drives.

Most Pulsar thermostats begin opening in the low‑80s Celsius and are fully open higher up, always match the spec for the engine code on the build plate or handbook.

• Replace the seal/O‑ring every time.
• Inspect housing for corrosion or cracks, replace if suspect.
• Check both radiator cap seals.
• Scan for and clear stored fault codes.
• Safely dispose of old coolant, it’s toxic to pets.

Where is the thermostat located on a 2017 Nissan Pulsar?

It’s mounted in a small housing on the engine, typically at the engine end of the lower radiator hose. Access is usually from the top/front of the bay, removing the intake ducting helps. Location and housing style vary slightly by engine, so check the under‑bonnet label and workshop information before starting.

How can they tell if it’s the thermostat or the coolant temperature sensor?

A stuck‑open thermostat gives slow warm‑up and weak cabin heat at speed, stuck‑closed causes overheating. A dodgy sensor can make the gauge read oddly while the heater feels normal. A scan tool reading that disagrees with an infrared check at the housing points to a sensor issue, not the thermostat.

Do they need to replace the thermostat when changing coolant?

Not strictly, but it’s good preventative maintenance on higher‑kilometre cars or after any overheating incident. If there’s a P0128 code, erratic temps, or signs of corrosion at the housing, fit a new thermostat and O‑ring with the coolant service and bleed the system carefully.