CVT radiator <em>Nissan Murano Z50</em>: signs of breakdown, replacement and selection of spare parts

Nissan Murano Z50 - a crossover that has gained popularity due to its comfort, reliability and powerful 3.5 liter VQ35DE engine, coupled with a variator Jatco JF011E. However, even the most well-thought-out transmission has a weak point - variator cooling radiatorthat clogs, leaks, or becomes ineffective over time. Ignoring problems with this part leads to overheating of the oil, accelerated wear of the belt and cones, and in critical cases, to complete failure of the CVT.

In this article we will look at how diagnose a faulty variator radiator on Murano Z50, what signs indicate the need for replacement, how to choose the right spare part (original or analogue) and perform the work yourself. We will also reveal a unique nuance of the radiator design on this model: it is integrated into the main engine radiator, which complicates diagnostics and repairs.

Signs of a faulty variator radiator on Nissan Murano Z50

CVT radiator Murano Z50 performs two key functions: cools the CVT oil and maintains its operating temperature within the range 80–100°C. When heat transfer is disrupted, symptoms arise that are often confused with breakdowns of the transmission itself. Here are the most characteristic signs:

• 🔥 CVT overheating: The indicator on the instrument panel lights up AT TEMP (especially in traffic jams or when towing), and the oil in the CVT takes on a burning smell.
• 🛢️ Oil leak: reddish spots appear under the car (variator oil color NS-2/NS-3), and the fluid level in the transmission drops.
• ⚡ Jerks and jerks when overclocking or switching modes (D → R), caused by changes in the viscosity of overheated oil.
• 📉 Power drop: the variator is “stupid” when overtaking, the engine speed increases, but the acceleration is weak (belt slipping).

Feature Murano Z50 — combined radiator, where the CVT cooling section is built into the main engine radiator. This means that if CVT oil leaks, it can mix with antifreeze to form an emulsion. Check the antifreeze expansion tank: if pinkish foam appears there, this is a sure sign of a breakdown of the internal radiator channels.

⚠️ Attention: If you ignore oil leakage from the variator into the cooling system, this will lead to jamming of the pump, overheating of the engine and major overhaul of both units. At the first sign of emulsion in antifreeze, immediately stop using the car!

CVT radiator design: why it fails

On Nissan Murano Z50 (2009–2014) in use combined radiator, where the CVT cooling section is located at the bottom of the main radiator. This solution saved space under the hood, but created several vulnerabilities:

• 🔧 Difficulty of diagnosis: A CVT oil leak is often disguised as an antifreeze leak because both fluids mix.
• 🕳️ Clogged channels: Over time, deposits from oil decomposition accumulate in the radiator tubes NS-2/NS-3, reducing heat transfer.
• 💥 Corrosion of aluminum honeycomb: Due to the temperature difference between the sections of the engine and the variator, microcracks occur.

Main causes of breakdowns:

Reason	Consequences	How to prevent
Natural wear (100–150 thousand km)	Oil leaking into antifreeze or out	Replacing the radiator at the first sign of a leak
Using low-quality CVT oil	Clogged channels, overheating	Only original oil Nissan NS-2/NS-3
Mechanical damage (stones, accidents)	Cell breakdown, leakage of both liquids	Installing Radiator Protection
Mixing different types of antifreeze	Corrosion, destruction of seals	Use only Nissan Long Life Coolant

Critical Feature: on Murano Z50 The variator radiator does not have a separate housing - it is soldered into the main radiator. This means that if one section fails you will have to change the entire assembly. Attempts to solder cracks rarely produce long-term results.

Original articles and analogues: what to choose for replacement

When replacing the radiator with Nissan Murano Z50 you have three options: an original part, high-quality analogues or a used unit. Let's look at each of them, indicating the article numbers and average prices (for 2026):

• 🔹 Original: 21410-JK00A (full radiator with CVT section). Price: 25 000–35 000 ₽. Guaranteed quality, but high cost.
• 🔹 Analogues (proven brands):
  • Denso 221-2860 — 18 000–22 000 ₽ (Japanese quality, complete analogue of the original).
  • Koyorad TYC 21410 — 15 000–19 000 ₽ (a good option for budget renovation).
  • Nissens 64304 — 16 000–20 000 ₽ (European manufacturer, reliable soldering).
• 🔹 Used radiators: price 5 000–12 000 ₽, but the risk of purchasing a part with hidden defects is extremely high. We recommend it only after a complete diagnosis by a specialist.

When choosing an analogue, pay attention to:

1. Honeycomb material: must be aluminum (copper corrodes faster).
2. Tube thickness: in cheap fakes they are thinner, which reduces heat transfer.
3. Presence of pressure relief valve (in the original it is located at the top of the radiator).

⚠️ Attention: There are radiators on the market without a variator cooling section (for example, from Nissan Pathfinder R51). They look similar, but don't fit for Murano Z50! Always check the part number and availability of CVT oil pipes.

How to distinguish a fake from the original?

Original radiator 21410-JK00A has:

- logo Nissan on the top bar,

- marking Made in Japan on the label,

- CVT oil pipes with thread for temperature sensor.

Counterfeits often lack a pressure relief valve, and the soldering is crude.

Step-by-step instructions for replacing the variator radiator

Replacing the radiator with Nissan Murano Z50 - a labor-intensive process that requires draining both fluids (antifreeze and CVT oil), removing the front bumper and grille. Opening hours: 4–6 hours for an experienced technician. Below is an algorithm with key nuances.

Drain the antifreeze (through the tap on the cylinder block)|Drain the oil from the variator (through the pan plug)|Disconnect the battery (negative terminal)|Remove the front bumper and radiator grille|Prepare new clamps and O-rings-->

Step 1: Drain liquids:

1. Drain the antifreeze through the valve on the cylinder block (lower left side of the engine). Use a container with a volume of at least 10 liters.
2. Drain the oil from the variator: unscrew the plug on the CVT pan (the key is on 24 mm). Wait until the drain is complete (approx. 7–8 liters).

Step 2. Dismantling the radiator:

• Remove the front bumper (unscrew the bolts under the wings and below, disconnect the clips).
• Unscrew the radiator grille (4 bolts under the hood and 2 below).
• Disconnect the antifreeze and CVT oil pipes (loosen the clamps first). Attention: The variator oil pipes have O-rings - they need to be replaced!
• Unscrew the radiator mountings (2 bolts on top and 2 on bottom) and carefully remove it.

Step 3. Installing a new radiator:

1. Move the variator temperature sensor from the old radiator (if it is working).
2. Install new O-rings on the CVT oil pipes.
3. Secure the radiator, connect the pipes (first antifreeze, then oil).
4. Refill with fresh antifreeze (Nissan Long Life Coolant) and oil to the variator (NS-3, volume 9.5 liters).

Step 4. Bleeding the system:

After replacement, it is necessary to remove air from the cooling system:

1. Start the engine, let it run 5–10 minutes at idle speed.
2. Check the antifreeze level in the expansion tank - add if necessary.
3. Warm up the variator to operating temperature (80–90°C) and check for smooth shifting.

Common replacement mistakes and how to avoid them

Even experienced craftsmen make mistakes when working with a variator radiator on Murano Z50. Here are the most common mistakes and ways to prevent them:

• 🚫 Using old CVT oil: Many people drain the oil, but fill it back in after replacing the radiator. This is strictly prohibited — it already contains wear and contamination products.
• 🚫 Savings on O-rings: CVT oil pipes have rubber seals that harden over time. Their replacement is mandatory!
• 🚫 Incorrect antifreeze pumping: If air is not removed from the system, the engine will overheat. Use a vacuum pump to fill.
• 🚫 Ignoring CVT adaptation: After draining the CVT oil, the transmission requires relearning. Without this, jerks and delays when switching are possible.

Another common mistake is tightening of clamps on the pipes. This leads to deformation of the rubber tubes and subsequent leaks. Tightening torque must be 1.5–2 Nm (use a torque wrench).

⚠️ Attention: If, after replacing the radiator, the variator begins to “kick” or makes noise, immediately check the oil level! An air lock may have formed during filling. To remove it, warm up the CVT to 60°C and switch the selector several times to all modes (P → R → N → D).

Prevention: how to extend the life of a variator radiator

The service life of the variator radiator is Nissan Murano Z50 can be significantly increased by following simple operating and maintenance rules. Here are the key recommendations:

• 🔄 Regular CVT oil change: every 60,000 km (or once every 3 years). Use only Nissan NS-3 (article KLE52-00004).
• 🧹 Radiator flushing: once every 100,000 km flush the variator cooling system with special compounds (for example, Liqui Moly Kuhler-Reiniger).
• 🚗 Avoid overload: Do not tow heavy trailers (maximum weight for Murano Z50 — 1,500 kg).
• 🌡️ Temperature control: in hot weather use the mode Sport less often - it increases the load on the CVT.

Additional measures:

measure	Effect
Installing Radiator Protection	Prevents punctures from rocks and debris
Using an external CVT cooler	Reduces oil temperature by 10–15°C
Check pipes every 30,000 km	Allows you to detect cracks in time

Important: If you frequently drive off-road or in high-temperature conditions (such as in southern regions), reduce the CVT oil change interval to 40,000 km. This will prevent deposits from forming in the radiator.

FAQ: Answers to frequently asked questions about the variator radiator Nissan Murano Z50

Is it possible to drive with a CVT radiator leak?

No! If CVT oil leaks, its level drops, which leads to oil starvation and accelerated wear of the belt and cones. If there is a leak in the antifreeze section, there is a risk of engine overheating. Operation prohibited until the problem is resolved.

How to check if CVT oil and antifreeze are mixed?

Open the cap of the antifreeze expansion tank. If there is pink emulsion or oil stains - liquids are mixed. Also check the variator dipstick: if the oil has become lighter or bubbles are visible in it, this is a sign of antifreeze ingress.

How much does it cost to replace a radiator at a service center?

Cost of working at an official dealer Nissan — 12 000–18 000 ₽. In independent services the price is lower: 8 000–12 000 ₽. Total amount with spare parts: 30 000–50 000 ₽ (depending on the choice of radiator).

Is it possible to repair a CVT radiator?

Theoretically, you can solder cracks or replace pipes, but this is a temporary solution. Due to the design (soldered-in CVT section), high-quality repairs are almost impossible. We recommend a complete replacement of the radiator.

What kind of oil should I pour into the variator after replacing the radiator?

Only original Nissan NS-3 (article KLE52-00004). Volume for complete replacement: 9.5 liters. The use of analogues (for example, Idemitsu CVTF) is acceptable, but reduces the life of the CVT.