INFINITI FX35 Radiator: A Guide to Replacement and Common Issues (2003-2012)
Keep your FX35's powerful VQ engine from overheating by understanding its radiator and choosing the right replacement.
- Radiator failure is common due to cracks in the plastic end tanks; inspect them regularly.
- When replacing the radiator, also replace the radiator cap, thermostat, and hoses for reliability.
- Use a blue-colored Asian vehicle P-HOAT coolant to protect your engine and cooling system.
- Premium aftermarket brands like Denso, CSF, and Nissens offer OEM-quality without the dealer price tag.
Understanding Radiator Failure in Your FX35
The radiator in the 2003-2012 INFINITI FX35 is a durable part, but it's not invincible. Over time, the constant cycles of heating and cooling can cause the plastic end tanks to become brittle and crack. Road debris can damage the cooling fins, and internal passages can get clogged by old, degraded coolant. When this happens, your engine's health is at risk.
Key Failure Symptoms to Watch For
- Engine Overheating: The most obvious sign. If your temperature gauge is in the red or you see steam from the hood, pull over immediately.
- Coolant Leaks: Puddles of green or blue fluid under the front of your car are a clear sign of a leak. You might also notice a sweet smell after driving.
- Low Coolant Light: If you're constantly having to top off your coolant reservoir, you likely have a leak somewhere in the system.
- Visible Damage or Corrosion: Look for cracked plastic tanks, bent fins, or white, crusty deposits on the radiator itself.
Known Issues: Plastic Tanks and Radiator Caps
The most common failure point for the FX35 radiator is the plastic end tanks cracking with age. This leads to coolant leaks and potential overheating. Additionally, a faulty radiator cap can cause issues. Infiniti issued a Technical Service Bulletin (TSB) for many models from this era regarding radiator caps where the gasket could swell, causing an improper seal and leading to coolant loss or overheating symptoms. If you are replacing your radiator, replacing the cap is a cheap and essential piece of preventative maintenance.
Choosing the Right Aftermarket Radiator
You don't need to buy a radiator from the dealership to get a quality part. Many aftermarket brands offer excellent quality, often meeting or exceeding original equipment (O.E.) specifications. Here’s a breakdown of some available brands:
- Premium Aftermarket (OEM-Equivalent): Brands like Denso, CSF, and Nissens are well-regarded in the industry. Denso is an original equipment manufacturer for many car brands, ensuring high quality. CSF and Nissens are known for their robust construction and good fitment, often with reinforced tanks and high-quality cores. Forum users frequently recommend Denso for its reliability and value.
- Standard Aftermarket: Spectra is a very common choice available at many local auto parts stores. While many users have success with them, some online reviews mention concerns about long-term durability and potential for internal failures compared to premium brands.
- Economy Brands: Brands like APDI, Onix, and Pro Parts fall into the budget-friendly category. These can be a viable option if cost is the primary concern, but they may not offer the same longevity or perfect fit as higher-tiered brands.
Pro Tip: When you replace your radiator, it's the perfect time to also replace the upper and lower radiator hoses, thermostat, and radiator cap. It's also critical to flush the system and refill with the correct coolant, which for the FX35 is typically a blue-colored Asian Phosphated HOAT (P-HOAT) type antifreeze.
Cost of Replacing an INFINITI FX35 Radiator
The cost can vary significantly based on the parts you choose and whether you do the work yourself. A DIY replacement is very feasible for those with moderate mechanical skill.
| Part/Service | Estimated Cost |
|---|---|
| New OEM Radiator | $620 - $800 |
| New Aftermarket Radiator | $142 - $449 |
| Shop Labor | $170 - $310 |
| Total Professional Replacement (Aftermarket Part) | $312 - $759 |
Frequently Asked Questions
Can a bad radiator damage my transmission?
Yes. The automatic transmission fluid is cooled by a circuit inside the radiator. If this internal cooler fails, coolant and transmission fluid can mix, creating a destructive pink, milky substance often called the "strawberry milkshake." This can quickly ruin a transmission, leading to a much more expensive repair. While this issue is famous on other Nissan models, any vehicle with an integrated cooler is susceptible if the radiator fails internally.
Is it difficult to replace the FX35 radiator myself?
For a moderately experienced DIY mechanic, it is not an overly difficult job. It involves draining the coolant, removing the airbox and fan shroud, disconnecting hoses and transmission cooler lines, and unbolting the radiator. It can typically be done in 2-4 hours. 🎬 Watch this step-by-step walkthrough of the full radiator replacement process. It is possible to do the job without disconnecting the A/C condenser.
🎬 Watch how to remove the radiator without disturbing the AC system.What type of coolant should I use in my 2003-2012 FX35?
You should use a blue or green long-life coolant specifically designed for Asian vehicles. These are typically Phosphated Hybrid Organic Acid Technology (P-HOAT) coolants. Using the wrong type of coolant can lead to corrosion and damage to the cooling system. Always use distilled water if mixing with concentrate.
Should I replace my radiator hoses and thermostat at the same time?
Yes, it is highly recommended. The cooling system is already drained and accessible, making it the perfect time to replace these relatively inexpensive wear items. Old hoses can become soft or brittle, and a thermostat can fail without warning, so replacing them with the radiator is smart preventative maintenance.
🎬 See how to replace the thermostat while your radiator is out.Helpful Videos
Technical Specifications
OEM Part Numbers: 21460-CG000 21460-CM80B 21460-1BH0A 21460-1CB0A
The radiator for the 2003-2012 INFINITI FX35 features an aluminum core for heat dissipation and plastic end tanks. It is a cross-flow or down-flow design and includes an integrated concentric transmission oil cooler with hose barb fittings for automatic transmission models.
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The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- INFINITI FX35: