Parts for your 2002 Nissan Serena-Radiator cap

2002 Nissan Serena Radiator Cap: Purpose, Care and When to Replace

Based on factory literature for the C24-series Serena (Cooling System section in the Nissan Serena C24 Service Manual) and the Nissan FAST electronic parts catalogue, the 2002 Nissan Serena is designed with a pressurised cooling system that uses a radiator cap. On most C24 models the pressure cap sits directly on the radiator’s top tank, some market variants place a pressure cap on a pressurised expansion tank. Either way, a radiator-style pressure cap is fitted and required.

The radiator cap’s job is more than just a lid. It seals the cooling system and holds a set pressure (commonly around 0.9 bar/13 psi on many C24s), which lifts the coolant’s boiling point so the engine can run efficiently without boiling over. It also contains two valves: a relief valve that vents excess pressure to the overflow bottle when things get hot, and a vacuum valve that draws coolant back in as the system cools, keeping air out and hoses from collapsing.

For owners looking after a 2002 Serena, the cap deserves a quick check at every service. If the rubber seal is cracked, the spring feels weak, or the cap won’t hold its rated pressure when tested, it’s time for a new one. A dodgy cap can show up as random overheating on the open road, coolant pushed into the overflow and not returning, gurgling after shutdown, or a top hose that goes flat as it cools.

Good practice under the bonnet includes:

• Only opening the cap when the engine is fully cool, wrap a rag around it and point away from the face.
• Inspecting the filler neck for corrosion or nicks that could stop the seal from seating.
• Testing the cap’s pressure with a cooling-system tester, replace if it can’t hold the stamped rating.
• Fitting a quality cap with the correct pressure rating for the Serena’s engine and market spec.

As a rule of thumb, many techs in Australia and New Zealand will replace a radiator cap every 2–4 years or 60–100,000 km, or sooner if testing says it’s not up to scratch. It’s a cheap bit of insurance for the C24’s cooling system.

Popular questions about 2002 Nissan Serena radiator caps

What pressure radiator cap does a 2002 Nissan Serena use?
Most 2002 Serena C24 models use a cap around 0.9 bar (13 psi), but owners should confirm the rating stamped on the existing cap or check against their VIN in a parts catalogue. Using the correct pressure is important to maintain the designed boiling point and hose integrity.

If the rating stamp is missing or the cap looks aftermarket, a workshop can quickly verify the correct spec and test the current cap while they’re at it.

How often should the radiator cap be replaced?
In local Aussie and Kiwi conditions, replacing the cap every 2–4 years (or 60–100,000 km) is common preventive maintenance. Heat cycles and coolant chemistry slowly fatigue the spring and seals.

If there are symptoms like coolant overflow, hard-to-trace overheating, or collapsed hoses after cooldown, replace the cap immediately and retest the system.

Where is the radiator cap on the 2002 Serena?
On most C24 Serenas, the cap sits on the radiator’s top tank, accessible when the bonnet is up. Some market variants have a pressurised expansion tank with the pressure cap mounted there instead.

If the radiator itself has no cap, owners should look for a sealed, hard plastic tank in the engine bay with a warning label—this will be the pressure cap location.