2025 Nissan Altima — Coolant Capacity & Type

The 2025 Nissan Altima holds approximately 7.0–7.8 quarts (6.6–7.4 liters) of coolant in a completely drained cooling system.

Quick answer

• Total cooling system capacity: about 7.0–7.8 qt (6.6–7.4 L) when dry; a routine drain-and-fill typically returns less (roughly 4–6 qt) because some coolant remains in the block and heater core.
• OEM coolant spec: Genuine Nissan Long Life Antifreeze/Coolant (Blue), P-HOAT chemistry (phosphated HOAT), blue color; use Nissan “Blue” (e.g., 999MP‑L25500P premix or equivalent that explicitly states Nissan/Infiniti Blue compatibility; silicate/borate/amine/nitrite-free).
• Mix ratio: 50/50 coolant and distilled water (or use Nissan’s 50/50 premix). In extreme cold, up to 60% concentrate max; never exceed 70%.

Capacity by engine option

For the 2025 Altima (North America), the lineup is 2.5L I4 only.

Note: Real-world refill after a standard radiator drain usually takes less than the total dry capacity. If you’ve opened only the radiator drain, expect to add ~4–6 qt before the level stabilizes and final top-off after bleeding.

Flush interval

• Normal service: Nissan’s Blue long-life coolant is typically serviced at about 10 years/135,000 miles (217,000 km) for the first change, then every 5 years/75,000 miles (120,000 km) thereafter. Always verify against the maintenance schedule in your owner’s manual or by VIN.
• Severe duty (frequent short trips, extreme temps, dusty/towing): Consider 5 years/75,000 miles, with annual inspections for level, concentration, and leaks.

How to refill & bleed

1. Start with a fully cool engine. Set the heater to full hot, fan low. Remove the reservoir (pressure tank) cap.
2. Drain: Open the radiator drain cock at the bottom (or remove the lower hose if no petcock). For a more complete service, some techs also open the engine block drain(s) where accessible; use a new sealing washer if specified.
3. Close drains. If equipped, open the air relief/bleeder plug on the engine’s coolant outlet/water outlet housing (top/front of the engine) to help purge trapped air during filling.
4. Fill slowly through the reservoir with Nissan Blue premix (or a 50/50 mix) until coolant runs steadily (no bubbles) from the bleeder; then tighten the bleeder. Continue filling to the COLD MAX mark.
5. Start the engine and let it idle. As it warms, momentarily raise rpm to ~2000 rpm in short bursts to move air. Squeeze the upper radiator hose gently to help burp air. Maintain the level near MAX as it drops.
6. When the thermostat opens and both radiator hoses are hot, the cooling fans should cycle. Check for strong cabin heat. Top up to MAX and install the cap.
7. Road test with the heater on, allow a full cool-down, then recheck and top off to the COLD MAX line. Recheck again the next morning.

Tech tip: A vacuum-fill tool is strongly recommended on the Altima’s pressurized reservoir system to avoid air pockets that can cause no-heat or overheating. If you don’t have a bleeder screw on your specific engine configuration, take extra time during warm-up and hose-burping to ensure a complete air purge.

Common cooling system issues on this generation (2019–2025)

• Air pockets after service: Inadequate bleeding can leave trapped air, leading to fluctuating temperature gauges or weak cabin heat. Always use the air relief point (if equipped) or a vacuum-fill tool.
• Thermostat housing/water outlet seep: Plastic/aluminum housings can develop minor leaks at gaskets or seams over time. Look for dried blue/white crust and address promptly.
• Electric cooling fan or control module faults: May cause overheating at idle or with A/C on. Verify both fan speeds and module command before condemning the radiator or pump.
• Water pump seepage or bearing noise: Check for crust at the weep hole and listen for growl/chirp noises. Replace pump and belt as needed.
• Radiator end-tank seam leaks: Plastic tank crimps can weep with age/heat cycles; watch the upper tank area for staining.
• Reservoir (pressure cap) degradation: A weak cap can lower system boiling point and invite aeration. Replace if the seal is cracked or spring is weak.
• Mixed coolant chemistry: Adding universal green or silicated coolant can shorten component life and precipitate deposits. Stick to Nissan Blue or a verified P‑HOAT compatible equivalent.

If in doubt about capacity, type, or persistent air issues, a professional vacuum fill and pressure test will save time and protect the engine. Find a trusted shop on Repairius.