2018 Nissan Murano Transmission Problems

The 2018 Nissan Murano, a stylish and comfortable crossover SUV, has been a popular choice for families and commuters alike. However, like many modern vehicles, it's not without its potential issues. One area that has garnered attention is the Murano's Continuously Variable Transmission (CVT). While CVTs offer potential benefits in fuel efficiency and smooth acceleration, they also have unique characteristics and potential failure modes that differ from traditional automatic transmissions. This article will delve into the common transmission problems reported with the 2018 Nissan Murano, explain the technical aspects in an accessible way, and provide practical advice for owners and enthusiasts.

Understanding the CVT in the 2018 Murano

The 2018 Murano typically uses a CVT, specifically the Jatco CVT8 (RE0F10D). A CVT, unlike a conventional automatic transmission with fixed gear ratios, uses a system of belts and pulleys to provide a virtually infinite number of gear ratios within its operating range. Think of it like a bicycle with an incredibly complex and ever-changing chain and sprocket system. Instead of distinct "gears" you feel shifting, the CVT seamlessly adjusts the ratio between the engine and the wheels.

This continuous adjustment allows the engine to stay in its optimal RPM range for either fuel economy or power, leading to advantages in both areas compared to some traditional automatic transmissions. For instance, imagine a traditional automatic in a car like a Toyota Camry. When you accelerate, you feel distinct shifts between 1st, 2nd, 3rd, and so on. With a CVT, like in some Subaru models, the acceleration feels more linear, almost like one long, smooth pull.

How a CVT Works (Simplified)

The key components of the CVT are:

Two Pulleys (Input and Output): These pulleys are cone-shaped and face each other. The distance between the cones changes, effectively altering the diameter of the pulley.
Steel Belt or Chain: This belt or chain connects the two pulleys and transmits power from the engine to the wheels.
Hydraulic System: This system controls the pressure that moves the pulley halves, which changes the gear ratio. It's the "brains" of the operation, responding to throttle input and other sensors.
Transmission Control Module (TCM): This computer monitors various sensors (speed, throttle position, etc.) and tells the hydraulic system how to adjust the pulleys.

As the engine speed increases, the TCM signals the hydraulic system to adjust the pulley ratios, keeping the engine in its optimal power or efficiency range. This happens smoothly and continuously, hence the name "Continuously Variable."

Common 2018 Murano CVT Problems

While CVTs offer advantages, they also have some drawbacks. The 2018 Nissan Murano, unfortunately, has seen reports of several CVT-related issues. It's important to note that not *every* 2018 Murano will experience these problems, but awareness is key.

Shuddering or Jerking: This is a common complaint, especially during acceleration or when maintaining a steady speed. It feels like the transmission is hesitating or vibrating. This is often caused by wear on the belt or chain, or problems with the valve body that controls hydraulic pressure.
Slipping: Slipping occurs when the engine RPMs increase, but the vehicle speed doesn't increase proportionally. It's like the transmission is struggling to hold the gear. This can be caused by low transmission fluid, internal damage to the belt or pulleys, or issues with the TCM.
Overheating: CVTs generate heat, and proper cooling is crucial. If the transmission overheats, it can lead to damage to the internal components. Overheating can be triggered by towing heavy loads, aggressive driving, or a faulty transmission cooler. Symptoms can include warning lights and erratic shifting.
Delayed Engagement: This happens when you shift into drive or reverse, and there's a noticeable delay before the transmission engages. This can be caused by low fluid pressure, worn valve body components, or internal damage.
Complete Transmission Failure: In the worst-case scenario, the CVT can fail completely, rendering the vehicle undrivable. This is usually the result of prolonged neglect of symptoms or severe internal damage.

Why These Problems Occur

Several factors can contribute to these CVT problems:

Design Limitations: Some argue that the CVT design itself is more susceptible to wear and tear than traditional automatics, especially when subjected to high stress or improper maintenance.
Fluid Degradation: CVT fluid is a specialized lubricant that's crucial for the transmission's proper operation. Over time, the fluid degrades, losing its lubricating properties and leading to increased wear and tear. Nissan recommends specific CVT fluid (NS-3), and using the wrong fluid can cause serious damage. It's more critical than simply using "generic" transmission fluid. Think of it like using the wrong type of oil in a high-performance engine; it might work for a short time, but long-term damage is almost guaranteed.
Driving Habits: Aggressive driving, frequent towing, and neglecting regular maintenance can all accelerate wear and tear on the CVT.
Manufacturing Defects: While less common, manufacturing defects can also contribute to CVT problems. A faulty component or improper assembly can lead to premature failure.

Technical Deep Dive: The Valve Body and TCM

Two key components play a significant role in CVT performance and are often implicated in problems: the valve body and the Transmission Control Module (TCM).

The Valve Body: Hydraulic Control Center

The valve body is a complex network of channels, valves, and solenoids that control the flow of hydraulic fluid within the transmission. It's like the central nervous system of the CVT, directing fluid to the correct locations to adjust the pulley ratios.

Over time, the valve body can become clogged with debris, or the valves and solenoids can wear out. This can lead to erratic shifting, slipping, and other performance problems. Imagine a complex plumbing system where some pipes are partially blocked or the valves are sticking; the whole system won't function properly.

The TCM: The Brain of the Operation

The TCM is the computer that controls the CVT. It receives input from various sensors (speed sensors, throttle position sensor, etc.) and uses this information to determine the optimal pulley ratio. It then sends signals to the valve body to adjust the hydraulic pressure accordingly.

A faulty TCM can cause a wide range of problems, including incorrect shifting, slipping, and complete transmission failure. Sometimes, the TCM can be reprogrammed or replaced to fix the issue. It's analogous to the engine control unit (ECU) in your car. If the ECU malfunctions, the engine won't run correctly, and the same is true for the TCM and the CVT.

Preventative Maintenance and Troubleshooting

The best way to avoid CVT problems is to follow a strict maintenance schedule and be aware of potential warning signs.

Regular Fluid Changes: This is the most important thing you can do to prolong the life of your CVT. Follow Nissan's recommended service intervals for CVT fluid changes, and use only the specified NS-3 fluid. Don't wait until you experience problems; preventative fluid changes are much cheaper than a transmission replacement.
Avoid Aggressive Driving: Aggressive acceleration and hard braking can put excessive stress on the CVT. Drive smoothly and avoid unnecessary strain.
Don't Tow Heavy Loads: Towing heavy loads can overheat the CVT and cause damage. If you need to tow, make sure your Murano is properly equipped and follow Nissan's towing guidelines.
Monitor for Warning Signs: Pay attention to any unusual noises, vibrations, or shifting problems. If you notice anything out of the ordinary, take your Murano to a qualified mechanic for inspection.
Consider an Auxiliary Cooler: If you live in a hot climate or frequently tow, consider installing an auxiliary transmission cooler to help keep the CVT from overheating.

Troubleshooting Steps

If you suspect you're experiencing CVT problems, here are some basic troubleshooting steps:

Check the Fluid Level: Make sure the CVT fluid level is correct. Consult your owner's manual for the proper procedure.
Inspect the Fluid Condition: The fluid should be a light green or blue color. If it's dark brown or black, it's likely degraded and needs to be changed. Also, check for a burnt smell.
Scan for Diagnostic Trouble Codes (DTCs): Use an OBD-II scanner to check for any DTCs related to the transmission. These codes can provide valuable clues about the source of the problem. Note that some advanced codes related to transmission may only be read by professional level scanners.
Consult a Qualified Mechanic: If you're not comfortable performing these checks yourself, or if you suspect a more serious problem, take your Murano to a qualified mechanic who specializes in CVTs.

Practical Takeaways

Here's what you, as a 2018 Nissan Murano owner or enthusiast, should take away from this information:

CVT maintenance is paramount. Adhere strictly to the recommended fluid change intervals using the correct NS-3 fluid. This is the single most important thing you can do.
Be observant. Pay close attention to how your Murano shifts and feels. Any unusual shuddering, slipping, or delays should be investigated promptly.
Don't ignore warning lights. If the transmission warning light illuminates, don't delay in getting it checked out. Early diagnosis can prevent more significant damage.
Choose a reputable mechanic. CVTs require specialized knowledge and equipment. Ensure your mechanic has experience working on CVTs, especially Nissan CVTs.
Consider your driving habits. If you frequently tow or drive aggressively, adjust your maintenance schedule accordingly and consider adding an auxiliary cooler.

By understanding the intricacies of the 2018 Nissan Murano's CVT and taking proactive steps to maintain it, you can significantly increase its lifespan and avoid costly repairs. Remember, preventative maintenance is always cheaper than a full transmission replacement.