Replacing Nissan Murano Z51 Spark Plugs: A Complete Guide

Proper maintenance of the ignition system is the foundation for long and reliable operation of the power unit on a crossover Nissan Murano second generation. Engine VQ35DE, installed on the model Z51, is highly responsive and powerful, but requires the spark elements to be in perfect condition. Ignoring routine maintenance to replace spark plugs can lead to an increase in fuel consumption and a decrease in acceleration dynamics.

Many owners are faced with the need to carry out this procedure themselves in order to save on service work or to ensure the quality of the installed parts. Unlike in-line engines, access to the rear cylinders here requires some preparation and care. A competent approach to the replacement issue will avoid damage to fragile components and ensure stable operation of the engine at high mileage.

Why is it important to change spark plugs on a VQ35DE engine on time?

Ignition system on Nissan Murano Z51 operates in extreme conditions of constant vibration and high temperatures. The standard replacement interval for this engine is 100,000 kilometers, but the actual service life often depends on the quality of the fuel and driving style. If you notice floating speed at idle or jerking during acceleration, diagnosing the spark plugs should be a priority.

Wear of the electrodes causes the gap to increase, which causes the ignition coil to produce higher voltage. This creates a tremendous burden on ignition coils, which are on Murano are an expensive and vulnerable element. Misfires caused by old spark plugs can lead to catalytic converter failure, which can cost significantly more to repair than a new batch of spark plugs.

Timely replacement allows you to maintain an ideal mixture of fuel and air, which is critical for the environmental friendliness and efficiency of the crossover. Regular Maintenance The ignition system prevents the accumulation of carbon deposits on the cylinder walls and valves. You shouldn't wait for one of the cylinders to completely fail before deciding to visit the garage.

Selecting suitable components and tools

For a successful procedure, you will need original parts or high-quality analogues that meet the manufacturer's specifications. At the factory in Nissan Murano Z51 Iridium spark plugs are installed, which have a long service life and a stable spark. The use of cheap copper analogues may lead to the need for replacement after 30-40 thousand kilometers.

• 🔥 Original candles Nissan 22401-ED000 or their iridium versions with markings PLFR5A-11.
• 🔧 Special spark plug wrench with extension and soft insert to protect ceramics.
• 💨 Compressed air or a can of compressed air to clean spark plug wells.
• 🧴 Graphite thread lubricant and silicone lubricant for O-rings.

Having a quality tool is key. A regular set of keys may not be suitable due to limited space in the engine compartment. You will need a spark plug wrench with an extension that will allow you to reach the rear spark plugs located closer to the interior. Also be sure to have a torque wrench ready to properly tighten the threads.

⚠️ Attention: Never use WD-40 or liquid lubricants on spark plug threads, as this can cause sticking and stripping of the threads in the cylinder head. Use only special heat-resistant pastes based on graphite or copper.

It is also important to check the condition of the ignition coils before installing new spark plugs. Often on older cars, carbon or oxidation forms on the coil contacts, which impairs spark transmission. If you are changing spark plugs, it is worth cleaning the coil contacts and checking the integrity of the rubber caps.

Preparatory stage and safety

Make sure the engine is completely cool before starting work. Working with a hot engine can lead to burns, as well as deformation of the aluminum parts of the cylinder head due to a sharp temperature change when screwing in cold spark plugs. Open the hood and disconnect the negative battery terminal to eliminate the risk of a short circuit.

Remove the decorative plastic engine cover. It is attached to several plastic clips, which easily break if removed carelessly. Lift the lid straight up without applying any lateral force. After this, you will see six ignition coils arranged in two rows of three.

• 🚫 Do not operate on a hot engine to avoid thread deformation.
• 🔌 Be sure to disconnect the battery before starting work.
• 🌬️ Clean the area around the candles from dust before twisting.
• 🧤 Use protective gloves to protect your hands from oil and dirt.

Pay special attention to cleaning the spark plug wells. Dust and dirt that gets into the cylinder when the spark plug is removed can cause serious engine damage. Use a can of compressed air or a powerful blower to blow out the area around the candles. This is a critical step that inexperienced craftsmen often skip.

Step-by-step instructions for replacing spark plugs

Start the procedure by removing the high-voltage wires or the ignition coils themselves. On Nissan Murano Z51 Individual coils are used, which are secured with one bolt. Unscrew the bolt securing the coil and carefully pull it up. If the reel is tight, use special pliers or gently rock it from side to side.

After removing the coil you will see a spark plug. Insert the spark plug wrench and extension all the way, making sure it fits snugly onto the edge of the spark plug. Unscrew the spark plug counterclockwise. If the spark plug is tightened too tightly, apply force, but do it smoothly so as not to strip the threads in the aluminum cylinder head.

Carefully inspect the removed old spark plug. The color of the deposit can tell you about the condition of the engine: black deposits indicate a rich mixture or oil problems, white deposits indicate overheating. If you see oil marks on the threads, this may indicate wear on the valve stem seals or valve cover gasket.

Install a new spark plug. Hand tighten it until it stops so as not to damage the threads. Then use a torque wrench for final tightening. Tightening torque for engine spark plugs VQ35DE is approximately 13 Nm. If you don't have a torque wrench, use the wrench to tighten the spark plug 1/8 to 1/4 turn after it rests against the gasket.

What to do if the candle is stuck?

If the spark plug cannot be removed, do not use excessive force. Apply penetrating lubricant to the threads and let it sit for 10-15 minutes. You can lightly heat the area around the candle with a hair dryer, but do not overheat the coils. If the spark plug still doesn’t work, it’s better to contact a professional so as not to break it in the block head.

⚠️ Attention: It is strictly forbidden to use lubricant to tighten the spark plug threads if it is not provided by the manufacturer. Excess lubricant can enter the combustion chamber and cause detonation or carbon deposits.

Nuances of working with rear cylinders

The hardest part of replacing spark plugs is Murano Z51 — this is access to the rear spark plugs (cylinders 4, 5, 6). They are located closer to the cabin partition and access to them is very limited. You will need a special extension and possibly a flexible cardan to secure the key properly.

When working on the rear spark plugs, be extremely careful not to damage any fuel lines or wiring harnesses running nearby. Make sure that the coils and wires are not pinched during assembly. Owners often forget that after installing new spark plugs, they need to put the coils on correctly and secure them with bolts.

Check the condition of the o-ring on the reel. If it has lost elasticity or cracked, oil may leak into the spark plug well. This will create conditions for carbon deposits to form on the new spark plug. If necessary, replace the O-ring or use silicone grease to restore it.

Table of characteristics and service intervals

To make it easier to compare different types of candles and their characteristics, we have prepared a summary table. This data will help you choose the best option for your driving style and vehicle operating conditions. Please note that deviations from specifications may adversely affect engine performance.

Candle type	Resource (km)	Electrode material	Tightening torque (Nm)
Original (Iridium)	100 000	Iridium	13
Analog (Platinum)	60 000	Platinum	13
Copper candles	30 000	Copper/Nickel	13
Forced (Sport)	20 000	Iridium/Platinum	13

Please note that even when using iridium spark plugs, their condition should be checked every 50,000 kilometers. A visual inspection will help identify ignition problems at an early stage. If you often drive around the city in traffic jams, the replacement interval should be reduced to 80,000 kilometers due to increased carbon formation.

Checking engine operation after replacement

After installing all the new spark plugs and coils, replace the decorative engine cover and connect the battery. Start the engine and let it idle. Listen to the engine: it should run smoothly, without vibrations or misfires. If you hear unusual noises or see a flashing Check Engine light, stop immediately and check the coil connections.

Take it for a test drive, paying attention to the response of the gas pedal. The engine should pick up speed smoothly and without jerking. If power loss is felt, one of the spark plugs may have been installed incorrectly or may have a manufacturing defect. In this case, repeat the procedure for checking all cylinders.

It is also worth checking for errors in the engine management system using a diagnostic scanner. Even if the Check Engine Light is not illuminated, old misfire-related error codes may remain in memory. Clear the error memory and make sure that they do not return after a short trip.

⚠️ Attention: If the engine runs unevenly after replacing the spark plugs, check to see if any dirt or oil particles have entered the spark plug wells. This may cause a short circuit or unstable spark operation.

Frequent maintenance errors

One of the most common mistakes is using the wrong tool. Trying to unscrew a spark plug with a regular open-end wrench or without an extension often leads to chips of the ceramic. A broken insulator part may fall into the cylinder, which will require serious engine repairs with disassembly of the cylinder head.

Another mistake is incorrect tightening torque. Tightening too weak will lead to the passage of exhaust gases and overheating of the spark plug, and too strong will lead to deformation of the threads or destruction of the ceramic insulator. Always use a torque wrench and follow the manufacturer's recommendations.

• ❌ Do not use lubricant on threads without special recommendations.
• ❌ Do not ignore cleaning spark plug wells before replacing.
• ❌ Do not change only part of the candles, change the set immediately.
• ❌ Do not install coils without checking their contacts.

Remember that ignition system is a complex and interconnected system. Replacing spark plugs is not just a mechanical procedure, but an opportunity to diagnose the condition of the engine. Regular maintenance and attention to detail will help your Nissan Murano Z51 remain a reliable companion for many years.

Frequently Asked Questions

Is it possible to replace spark plugs yourself without experience?

Yes, replacing spark plugs with Nissan Murano Z51 Even a beginner can do it with a basic set of tools and attentiveness. The main thing is to be careful when working on the rear cylinders and not allow dirt to get into the engine.

What is the tightening torque for spark plugs for a VQ35DE engine?

The recommended tightening torque is 13 Nm. If you don't have a torque wrench, screw the spark plug all the way in, then tighten it 1/8 to 1/4 turn.

How often do you need to change spark plugs on a Murano Z51?

Official regulations require replacement every 100,000 kilometers for iridium spark plugs. However, when driving actively around the city, it is recommended to check their condition every 50,000 km.

What to do if the spark plug is stuck in the cylinder head?

Do not try to unscrew it by force. Apply penetrating lubricant to the threads, give it time to soak in, and try again. If this does not help, it is better to contact a specialized service to avoid thread failure.

Can I use regular copper spark plugs instead of iridium spark plugs?

Technically it is possible, but they have a significantly shorter lifespan (about 30,000 km) and require more frequent replacement. This can lead to increased fuel consumption and stress on the ignition coils.

Why does the Check Engine light come on after replacing the spark plugs?

If the Check Engine light comes on after replacing the spark plugs, it is possible that old errors have been stored in the engine memory. Try clearing errors using a diagnostic scanner or disconnecting the battery for 10 minutes. If the error returns, check that the coils are installed correctly and that there is spark.