Parts for your 2017 Nissan Pathfinder-Radiator cap

2017 Nissan Pathfinder Radiator Cap

Based on Nissan’s technical literature, the 2017 Nissan Pathfinder (R52 series) uses a pressurised cooling system where the pressure cap is mounted on the coolant reservoir (degas bottle), not on the radiator itself. The Nissan Owner’s Manual for 2017 directs coolant checks and cap removal at the reservoir, and the R52 Factory Service Manual (Cooling System – CO section) identifies a reservoir tank cap as the system’s pressure-control point with a sealed radiator. So, a “radiator cap” is relevant to this model, but it’s located on the reservoir rather than on the radiator neck.

For this Pathfinder, the radiator cap’s job is simple but critical: it seals and pressurises the cooling system so the coolant can run hotter without boiling, helping the VQ-series 3.5‑litre engine keep its cool on long Kiwi and Aussie drives. The cap’s spring-loaded valve holds a set pressure, boosting the boiling point and preventing localised hot spots. As the engine cools, the cap’s vacuum valve opens to draw coolant back from the reservoir, keeping the system topped and free of air. It’s a small part that protects head gaskets, hoses, and the water pump from pressure spikes and cavitation.

As part of routine servicing for a 2017 Pathfinder, the cap deserves a quick once-over under the bonnet. A tired cap can allow slow coolant loss, make starting from cold a bit noisy with trapped air, or nudge the temperature gauge higher on climbs or when towing. Many workshops test the cap annually and replace it whenever the coolant is renewed. Using an OE-spec pressure rating and the correct cap style for the reservoir is essential, going softer can invite boil-over, while going harder can stress hoses and the heater core.

Good practice for owners and fleets includes:

• Inspecting the cap’s rubber seals for nicks, hardening, or flattening.
• Checking the spring action, if it feels weak or gritty, fit a new cap.
• Cleaning the reservoir neck so the seal seats properly.
• Only removing the cap when the engine is stone cold, wrap a rag around it and crack it slowly.
• Refilling with Nissan-approved long-life coolant and bleeding air per the service manual.

Kept in good nick, the cap helps stabilise temperatures, maintains heater performance in winter, and extends the life of hoses and gaskets. It’s a low-cost item that pays its way, especially on vehicles that tow, see hot summers, or rack up high kilometres.

Popular questions about the 2017 Nissan Pathfinder radiator cap

Does the 2017 Pathfinder have a cap on the radiator itself?
No. On this model the pressure cap is fitted to the coolant reservoir (degas bottle), while the radiator is sealed. Cap checks and removal are done at the reservoir and only when the engine is completely cold.

What pressure rating should the cap be?
Use an OE-equivalent cap with the same pressure rating and fitment as specified by Nissan for the R52. Many Nissan caps of this era are around 1.1 bar (approximately 16 psi), but the correct rating can vary by market and build. Confirm via the existing cap’s markings, the under‑bonnet label, or a trusted parts catalogue.

When should the cap be replaced?
Replace the cap if it fails a pressure test, shows damaged seals or corrosion, or whenever the cooling system is serviced and coolant is renewed. As a rule of thumb, testing annually and replacing around major coolant intervals or at the first sign of issues is a smart move.