Parts for your 2009 Nissan Pathfinder-Radiator

2009 Nissan Pathfinder radiator — purpose, service and replacement

Yes — the 2009 Nissan Pathfinder (R51, VQ40DE V6 and VK56DE V8) uses a conventional liquid‑cooled aluminium radiator. This is documented in the Nissan 2009 Pathfinder Factory Service Manual (Cooling System “CO” section) and the Nissan Electronic Parts Catalogue, which lists a dedicated radiator assembly and related hoses, cap, and fan shroud. Nissan’s technical communications for 2005–2010 Pathfinders also reference the integrated automatic‑transmission cooler inside the radiator, further confirming its fitment.

The radiator’s whole job is to pull heat out of the engine coolant and keep the donk in its happy operating range. Coolant flows through fine tubes, the fans and vehicle airflow whip heat away, and the thermostat and cap keep pressure and temperature in check. On automatic models, the radiator also houses a heat‑exchanger for the transmission fluid, so it’s doing double duty.

As part of routine servicing, it’s smart to check the coolant level and colour, look for dried pink/white crust around the end tanks and hose necks, and squeeze the upper and lower hoses for softness or cracking. A quality cap maintains the right pressure, so replace a tired cap along with any swollen hoses. Use Nissan Genuine Blue Long Life Coolant (or an equivalent silicate‑free, phosphate‑based premix) at about 50/50 with demineralised water. In typical AU/NZ conditions, plan coolant replacement roughly every 5 years or 100,000 km, and sooner if you’re towing, off‑roading, or running in hot climates. Always bleed the system properly — heater on, bleed screw opened where fitted, and no air pockets left under the bonnet.

If the Pathfinder runs hot, the temp gauge yo‑yos, there’s a sweet smell after a drive, or coolant looks rusty or oily, get a pressure test done and inspect the plastic tank seams. Owners of 2005–2010 autos should be alert for any milky “strawberry” contamination — a sign of the known radiator ATF cooler issue. Preventive steps include regular inspection, using an updated radiator, or fitting an external trans cooler as appropriate.

When replacing the radiator, go OEM‑quality or better, swap in new hoses and clamps, renew the cap and thermostat, and refill with the correct coolant. After a shakedown drive, recheck levels and for any weeps. Treat it right and the Pathfinder’s cooling system will handle Aussie summers and Kiwi alpine trips without breaking a sweat.

• Technical sources: Nissan 2009 Pathfinder (R51) Factory Service Manual — Cooling System (CO) section.
• Nissan Electronic Parts Catalogue — Radiator Assembly and cooling components for 2009 Pathfinder.
• Nissan technical communications on 2005–2010 Pathfinder radiator/ATF cooler contamination risk.

FAQs

How often should the coolant be changed on a 2009 Pathfinder in Australia or New Zealand?
Nissan’s long‑life blue coolant is built for extended intervals, but a practical schedule is about every 5 years or 100,000 km, with an annual condition check. If the vehicle sees heavy towing, beach work, or lots of low‑range off‑roading, shorten the interval. Always use demineralised water with the correct coolant type.

What are the signs the radiator is failing on a 2009 Pathfinder?
Watch for overheating, fluctuating temps, low coolant with no obvious leaks, white/pink crust at the tank seams, a sweet coolant smell, or discoloured fluid. For autos, any pink/milky mix in the overflow or ATF needs immediate attention due to the known internal cooler issue.

Can a competent DIYer replace the radiator at home?
Yes, it’s a moderate DIY. You’ll drain the system, remove the fan shroud, disconnect hoses and (on autos) the trans cooler lines, swap the radiator, then refill and bleed. Capture and recycle old coolant responsibly, and double‑check for leaks and proper level after a test drive.