Vehicle operation Nissan Murano involves regular maintenance, where the ignition system plays a special role. Over time, the life of the spark plugs ends, which leads to loss of power, increased fuel consumption and unstable engine operation. Many crossover owners ignore this nuance until they encounter serious problems, such as misfires or difficult starting in the cold season.
Replacement process on models with engine 3.5 V6 (VQ35DE or VQ35HR series) has its own characteristics due to the dense layout of the engine compartment and the specific location of the rear spark plugs. Incorrect actions can lead to damage to the ceramic insulators or stripping of the threads in the cylinder head. In this article we will analyze in detail the selection of the right components, the preparatory stages and the dismantling and installation procedure itself.
Symptoms of wear and diagnosis of the ignition system
You can determine the need to replace spark plugs not only by mileage, but also by the behavior of the car. Engine VQ35 It is quite responsive, so any malfunctions in the ignition system are immediately noticeable. If you feel a vibration at idle or notice a jerk when accelerating, this is the first sign that the spark has become unstable. Misfires can lead to unburnt fuel entering the exhaust system, which is dangerous for the catalyst.
Drivers often confuse problems with spark plugs with faulty ignition coils. On Nissan Murano coils often fail before spark plugs, but their work is closely interrelated. If one spark plug wears out, the coil feeding that cylinder begins to work harder and may burn out. Therefore, when diagnosing, it is important to check the condition of both components simultaneously.
Also, pay attention to fuel consumption. A sharp increase in gasoline consumption without changing driving style may indicate inefficient combustion of the mixture. A visual inspection of the removed spark plugs will also provide a lot of information: carbon deposits, oil or electrode erosion indicate various problems in the engine.
- π Deterioration in acceleration dynamics and loss of engine power
- π₯ Unstable engine operation at idle (triple)
- β½ Increased fuel consumption and reduced environmental friendliness
- π‘ Check Engine light on dashboard
Choosing the right candles and the necessary tools
The basis for a successful replacement is the correct choice of components. For engine 3.5 l on Nissan Murano (generation Z50, Z51, Z52) the manufacturer recommends using iridium spark plugs. They have a thinner central electrode and are designed to last a long time, providing a stable spark even under high loads. The use of conventional nickel analogues may lead to the need for frequent replacement and problems with starting in cold weather.
The most popular and proven options are original candles Nissan or their high-quality analogues from brands NGK and Denso. It is important to pay attention to the article numbers, since different modifications may be suitable for different years of production. An error in choosing the clearance or thread length will lead to the impossibility of installation or damage to the piston group.
The tools for the job must be specialized. A regular set of wrenches will not work here due to the cramped space in the engine compartment. You will need an extended spark plug head, a torque wrench and thread protectors. Don't forget about compressed air to clean the seats from dust and dirt before unscrewing.
- π§ Extended spark plug head
16 mm(preferably with a magnet or rubber holder) - βοΈ Torque wrench for precise tightening (torque
11-13 Nm) - π¨ Compressed air cylinder and funnel for access to the rear spark plugs
- π§Ό Graphite lubricant or copper thread paste (do not use lithol!)
β οΈ Warning: Never use silicone-based lubricant on spark plug threads. When heated, it can turn into a sticky mass that sticks to the head of the block, and it will be extremely difficult to unscrew the spark plug next time.
- Original Nissan
- NGK Iridium
- Denso Iridium
- Other brand
Preparing the engine for the replacement procedure
Allow the engine to cool completely before starting work. Working on a hot engine is dangerous and technically impractical: the aluminum of the cylinder head expands when heated, and the risk of stripping the thread when unscrewing increases many times over. The ideal temperature is when you can rest your hand comfortably on the valve cover. This rule applies to all engines. VQ series.
Next, you need to remove the decorative plastic engine casing. It is secured with several rubber clips and sometimes with bolts. Be careful when removing to avoid damaging the plastic clips. After removing the casing, you will have access to the ignition coils and high-voltage wires. On Murano the coils are installed directly on the spark plugs, which simplifies the design, but requires care when dismantling them.
Before removing the spark plugs, it is extremely important to clean the area around them from dust and dirt. If you just start revving, carbon particles will get into the cylinders, which can lead to scoring and costly repairs. Use compressed air to blow out the seats, especially if you're working in a dusty garage.
- βοΈ Allow the engine to cool to room temperature for at least 2 hours
- π§Ή Thoroughly blow out the area around the coils with compressed air
- π Disconnect the negative terminal from the battery for safety
- πΈ Take a photo of the location of the wires and coils for ease of assembly
If you don't have a compressed air compressor, use a soft brush and vacuum cleaner, but do it as carefully as possible so as not to scatter dirt around the engine.
Step-by-step instructions for dismantling and installation
The replacement process begins with access to the ignition coils. Disconnect the electrical connector from each coil by pressing the latch. Then unscrew the bolt securing the coil and carefully remove it from the landing well. Do not pull on the wire, only pull on the coil body. If the reel is tight, use a gentle rocking motion to free it from stuck rubber.
The next stage is unscrewing the candles. Insert the extended spark plug head onto 16 mm and begin to slowly loosen the spark plug. If the spark plug is tight, use a torque wrench in the loose setting to control the torque. Unscrew the spark plug by hand until the end so as not to damage the insulator. Pay special attention to the rear spark plugs (cylinders 2, 4, 6), which are difficult to access and often require the use of an angle attachment or flexible extension.
Installing new spark plugs requires compliance with the tightening torque. Apply a drop of copper paste or graphite lubricant to the threads (threads only, not the insulator!). Screw the spark plug in by hand as far as it will go so as not to distort it. Then use a torque wrench. Tightening torque for engine spark plugs VQ35 is strictly 11-13 Nm. Over-tightening can lead to destruction of the ceramics, and under-tightening can lead to burnout of the head gasket.
ΠΠΎΠΌΠ΅Π½Ρ Π·Π°ΡΡΠΆΠΊΠΈ: 11-13 ΠΠΌ (8-10 ft-lb)After installing the spark plugs, replace the ignition coils. Make sure they click until they click and are pressed tightly against the candles. Secure them with bolts and connect the electrical connectors. Assemble the decorative engine cover and connect the battery. Start the engine and check idle speed. If the vibrations have disappeared and the engine runs smoothly, the job has been completed successfully.
β οΈ Attention: If you hear a hissing sound or the engine is shaking when starting, immediately turn off the engine and check that the spark plugs are tightly screwed in and the coils are installed. Hissing indicates air leakage through a loose spark plug seal.
βοΈ Check before launch
Features of access to rear spark plugs on Nissan Murano
The hardest part of the job Nissan Murano β this is replacing spark plugs in the rear row of cylinders (closer to the passenger compartment). Due to the tight layout of the engine compartment, especially on models with heavy-duty air conditioning or attachments, direct access is not possible. It is often necessary to remove or move aside the throttle body, crankcase ventilation system pipes, and even part of the intake manifold.
To access the rear spark plugs, it is recommended to use a special extension with an angled adapter or a flexible cardan. Regular rigid extension cords may not be suitable due to the lack of room to turn the handle. Some craftsmen prefer to remove the coils completely and use a magnetic attachment to push the spark plug down and then unscrew it through the top, but this requires great precision.
If you are not confident in your abilities or do not want to disassemble half of the engine, it is better to turn to professionals. Improper manipulation of the intake manifold can damage sensors or gaskets, which will result in additional costs. Remember that saving time on replacing the rear spark plugs may cost you time to eliminate the consequences of errors.
- π οΈ Use a flexible driveshaft or an angle attachment for the rear cylinders
- π If necessary, remove the throttle assembly to improve access
- π Use a flashlight to visually control the twisting process
- 𧀠Wear gloves to protect your hands from sharp edges of parts
Do I need to remove the intake manifold?
On most Murano models (Z51, Z52), complete removal of the intake manifold is not required; just unscrew the throttle and move the pipes to the side. However, on early versions of the Z50, access may be even more limited, and partial removal of the manifold becomes inevitable.
Comparison table of popular candles for Murano
To choose the best option, letβs compare the main characteristics of popular candles available on the market. The original always remains the standard, but quality analogues often offer better value for money. It is important to consider the electrode material and recommended replacement interval.
| Brand and model | Electrode material | Resource (km) | Approximate price |
|---|---|---|---|
| Nissan (Original) | Iridium | 60 000 - 80 000 | Average |
| NGK Laser Iridium | Iridium | 90 000 - 100 000 | High |
| Denso Iridium Power | Iridium | 80 000 - 90 000 | High |
| Champion Copper Plus | Copper | 20 000 - 30 000 | Low |
Please note that copper spark plugs, despite their low price, require replacement every 20-30 thousand kilometers. For Nissan Murano with its powerful motor this is not practical as frequent replacement increases the risk of thread damage. Iridium spark plugs are the only right choice for modern VQ35 engines, ensuring stable operation throughout the entire declared service life.
When purchasing, always check the packaging for holograms and protective quality marks. Counterfeits are common, and the use of low-quality spark plugs can lead to failure of the ignition coils and catalyst. Buy components only from trusted suppliers or official auto parts stores.
β οΈ Attention: Avoid buying candles secondhand or in markets without a guarantee. Fake iridium spark plugs often have a copper electrode coated with a thin layer of iridium, which wears off after the first hundred kilometers.
Iridium spark plugs are not just marketing, but a necessity for VQ35 engines, ensuring long service life and stable operation of the ignition system without the need for frequent maintenance.
Common mistakes and ways to prevent them
Even experienced craftsmen sometimes make mistakes when replacing candles with Nissan Murano. The most common problem is stripped threads in the cylinder head. This happens if the spark plug is screwed in crookedly or with excessive force without a torque wrench. Repairing such damage requires installing an insert (footer), which is a complex and expensive procedure.
Another mistake is ignoring the condition of the ignition coils. If you change the spark plugs but keep the old coils, they may not provide the proper breakdown voltage. This will lead to new spark plugs working ineffectively and their service life will quickly decrease. Always inspect the coils for cracks, signs of breakdown and oxidation of the contacts.
It is also worth mentioning the problem with the rubber tips of the wires (if any) or the coil seals. Over time, the rubber becomes dull and cracks. When removing the coil, its body can be damaged if it is stuck to the spark plug. Use a spray lubricant to remove any rust or dirt, but do not allow it to get inside the cylinder.
- π« Do not tighten candles βby handβ without controlling the tightening torque
- π Always check the condition of the coils before installing new spark plugs
- π§Ό Never remove a spark plug if there is oil or dirt in the cylinder
- π Use an extension to avoid distortion when screwing
What to do if the spark plug breaks while unscrewing?
If the ceramic part of the insulator breaks off and remains in the well, do not try to remove it with a magnet, as fragments may fall into the cylinder. Use a vacuum suction or epoxy resin syringe (with caution) to draw out the shards. In the worst case, the cylinder head will need to be removed.
FAQ: Answers to frequently asked questions from owners
How many spark plugs are needed for a complete replacement on a Nissan Murano?
On all models Nissan Murano with gasoline engine 3.5 l 6 cylinders are installed, therefore, a complete replacement requires a set of 6 spark plugs. Don't skimp and replace them all at once, as they wear out about the same.
Can I use regular spark plugs instead of iridium spark plugs?
Technically possible, but not recommended. Conventional spark plugs have a shorter lifespan and require more frequent replacement. On the engine VQ35 this can lead to unstable operation and increased fuel consumption. Iridium plugs provide better gap and spark stability.
How often do you need to change spark plugs on a Nissan Murano?
The manufacturer recommends replacing every 60,000 - 80,000 km mileage for iridium spark plugs. However, if you operate the car in difficult conditions (urban cycle, traffic jams, short trips), it is recommended to check their condition every 40,000 km.
What should I do if the engine is unstable after replacement?
First check that the spark plugs are screwed in correctly and that the coils are installed correctly. If the problem persists, there may have been an error in the tightening torque or a poor-quality part was installed. It is also worth checking the condition of the coils and high-voltage wires.
Do I need to remove the battery before replacing spark plugs?
Yes, it is recommended to disconnect the negative terminal of the battery before starting work. This will eliminate the risk of a short circuit if the tools accidentally touch metal parts of the engine or wiring.