The ignition system is one of the most critical components in the engine Nissan Murano first generation (Z50 body). The VQ35DE engine that powers these vehicles has a high compression ratio and specific sparking requirements. If you notice a loss of power, an increase in fuel consumption, or unstable engine operation at idle, most likely the problem lies in the spark plugs.
Many crossover owners ignore the scheduled replacement periods, believing that modern iridium elements last forever. However, in the conditions of Russian roads, with temperature changes and not always high-quality fuel, the service life of spark plugs is reduced significantly. Timely maintenance allows you to avoid costly repairs of ignition coils and catalysts.
The process of replacing spark plugs Nissan Murano Z50 has its own technical features related to the layout of the engine compartment. In this article, we will look in detail at how to choose the right components, what needs to be prepared, and how to do the work yourself without the risk of damaging expensive components.
Maintenance schedule and signs of wear
The manufacturer recommends replacing spark plugs every 45,000 kilometers mileage However, in practice this interval often has to be shortened. If the car is operated primarily in the urban cycle with frequent traffic jams, the service life of the parts may be reduced to 30,000 km. It is important to understand that even a visually serviceable spark plug may have microscopic cracks in the insulator or a depleted electrode, which disrupts the combustion process of the mixture.
You can determine the need for replacement not only by mileage, but also by the behavior of the car. The first warning sign is misfire, which feels like jerks or dips when you press the gas pedal. The engine begins to run rough and the Check Engine light may come on intermittently or stay on. Another characteristic feature is the difficulty of starting the engine in the cold season.
Another important factor is the condition of the ignition coils. In design Nissan Murano Z50 The coils are installed directly on the spark plugs. If you have not changed the spark plugs for a long time, carbon deposits can damage the coil insulators, which will lead to their failure and the need to replace the entire module. Therefore, diagnosing candles should be a regular procedure, and not an emergency measure.
⚠️ Attention: Operating a vehicle with faulty spark plugs may allow unburned fuel to enter the catalyst, causing it to overheat and destroy. Replacing a catalyst costs tens of times more than a set of spark plugs.
Choosing the right spark plugs for the VQ35DE engine
Original spark plugs supplied for Nissan Murano, have a catalog number Nissan 22401-ED010 (or similar depending on the year of manufacture). They are equipped with iridium coating, which ensures long service life and a stable spark. However, it is not always worth buying the original, since there are high-quality analogues on the market from leading manufacturers, which are often cheaper and are in no way inferior in characteristics.
Among the popular alternative brands it is worth highlighting NGK and DENSO. The NGK Laser Iridium (PN ILZKR7B-11) or DENSO Iridium TT (FX22TT) are excellent options for the VQ35DE engine. It is important to make sure that you buy iridium or platinum spark plugs, since ordinary copper elements will quickly fail under the load of this motor.
When choosing, pay attention to the packaging and the presence of protective holograms. Counterfeit spark plugs often have rough castings, incorrect clearances and poor threads, which can cause the element to jam in the cylinder head. Always check the production date, as electrodes oxidize over time, even in packaging.
- ✅ Check the electrode gap: for this motor it should be exactly
1.1 mm(although iridium plugs usually come with a factory adjusted gap). - ✅ Make sure there is an iridium tip on the central electrode and a platinum plate on the side.
- ✅ Compare the length of the threaded part: it must exactly match the original sample so as not to damage the piston or valves.
Preparing tools and work area
Before starting work, you need to prepare a set of tools. You will need a quality ratchet wrench, an extension (extension rod) and, most importantly, a spark plug wrench with a magnetic holder or rubber insert. Standard size of spark plug wrench for Nissan Murano — 16 mm (5/8 inch). The use of a conventional open-end wrench is strictly not recommended due to the risk of stripping the threads or damaging the insulator.
You also cannot do without a can of penetrating lubricant (WD-40 or equivalent) and compressed air. Before unscrewing the spark plugs, it is necessary to thoroughly blow out the spark plug wells so that dirt and dust do not get inside the cylinder. This is a critical step that many beginners skip, which leads to rapid wear of the cylinder-piston group.
Additionally, it's worth preparing a new set of gaskets if you plan to replace them (although reusable copper washers are often used on iridium spark plugs, but it's better to be safe). Don't forget about gloves and contact degreasing agent if you decide to clean the ignition coils.
- Original Nissan
- NGK
- DENSO
- Other brand
Step-by-step instructions for replacing spark plugs
The first step is to remove the decorative plastic engine cover. It is secured with several latches and sometimes bolts. Gently pull the cover up to gain access to the ignition coils. After this, disconnect the connectors with wires from each coil by pressing the latch.
Unscrew the ignition coil mounting bolts with a 10 mm wrench. Remove the coils from the spark plug wells. If the reel is tightly seated, you can wiggle it slightly, but do not apply excessive force so as not to break the plastic housing. Now you see the candles themselves. Spray a generous amount of penetrating lubricant into the area where the spark plug and cylinder head meet to make unscrewing easier.
Blow out the spark plug wells with compressed air. This will remove accumulated dust and remaining oil. Now you can start unscrewing the spark plugs with a spark plug wrench. Do it slowly and smoothly. If the spark plug does not budge, do not use brute force, but let the lubricant work for a few more minutes.
☑️ Preparing to replace spark plugs
After unscrewing the old spark plug, carefully inspect its insulator and electrode. Compare its color and condition with the new one. If the carbon deposits are black and greasy, there may be a problem with the crankcase ventilation system or fuel quality. If the carbon deposits are white and dry, the engine may overheat. Install the new spark plug, tightening it by hand until it stops so as not to damage the threads.
Tighten the spark plug with a torque wrench 20-25 Nm. If you do not have a torque wrench, tighten the spark plug with a spark plug wrench, focusing on the resistance: after the spark plug rests on the gasket, tighten it another 1/4 or 1/2 turn (for new spark plugs with a gasket). Excessive force can lead to a crack in the cylinder head.
⚠️ Attention: Remember the procedure for installing candles. If you are replacing them all at once, be careful not to mix up the ignition coils, as they may have different levels of wear. It is better to mark them or change them strictly in the order of the cylinders.
What to do if the spark plug does not unscrew?
If the spark plug is stuck, do not try to unscrew it with a jerk. Moisten with penetrating lubricant and let stand for 15-20 minutes. Try lightly tugging up and down to break up the carbon deposits. If this does not help, heat the area around the spark plug with a hair dryer (not open fire!) so that the metal expands and the gap increases.
Common mistakes and how to avoid them
One of the most common mistakes is using the wrong spark plug wrench or missing a magnetic holder. The candle may fall into the well when lowered. If this happens, do not panic and do not try to pry it out with a screwdriver. Use a special magnetic hook or tube with a magnet inside to carefully remove the part.
Another mistake is ignoring the condition of the ignition coils. When removing coils, it is often discovered that their insulators are covered with soot or cracks. In this case, the coil must be thoroughly cleaned or replaced. Ignoring this factor will lead to the fact that even new spark plugs will not work correctly due to breakdown in the body.
Owners often forget to check the gap on new spark plugs. Although manufacturers claim factory settings, transportation and storage can affect the electrode geometry. Checking the gap with a feeler gauge will only take a couple of minutes, but will save you from future starting problems.
| Parameter | Value for VQ35DE | Note |
|---|---|---|
| Key size | 16 mm (5/8") | Standard size for Murano Z50 |
| Torque | 20-25 Nm | Use a torque wrench |
| Electrode gap | 1.1 mm | Check with a probe before installation |
| Thread type | M14 x 1.25 | Thread length 26.5 mm |
Before installing the ignition coils, apply a thin layer of dielectric grease to the inner walls of the wells and to the spark plug contacts. This will prevent the coils from sticking and protect against breakdown.
Results and recommendations for use
Replacing spark plugs with Nissan Murano Z50 is a procedure that every owner can perform with a minimum set of tools. The main thing is to be careful, take your time and use high-quality components. Regular replacement of spark plugs guarantees stable engine operation, economical fuel consumption and no starting problems.
Don't forget that the VQ35DE engine requires quality maintenance. If you notice that after replacing the spark plugs the problem does not go away, it is worth checking the condition of the coils, fuel injectors and crankcase ventilation system. An integrated approach to diagnostics will reveal the true cause of the malfunction.
Remember that timely replacement of spark plugs with iridium elements can extend the life of the catalyst and ignition coils by tens of thousands of kilometers. Saving on consumables often leads to much higher repair costs in the future. Take care of your car and follow the recommendations for routine maintenance.
The use of high-quality iridium spark plugs and compliance with the tightening torque are the key to long and reliable operation of the Nissan Murano Z50 engine.
Frequently Asked Questions
Is it possible to mix old and new candles?
No, it is strictly not recommended to mix old and new spark plugs in the same engine. Varying degrees of wear and resistance to sparking will lead to imbalance in cylinder operation, loss of power and increased fuel consumption. Always change the entire set.
What to do if the candle spins crookedly?
If you feel that the candle is misaligned, stop tightening immediately. Unscrew it completely and inspect the threads. If the threads on the spark plug or cylinder head are not damaged, try tightening it again, starting by hand. If the threads are stripped, the cylinder head will need repair or the use of threaded inserts.
Do I need to change spark plug gaskets?
For iridium spark plugs that are installed on Nissan Murano Z50, gaskets are often part of the design and do not require replacement at every service. However, if the gasket shows signs of deformation or carbon deposits, it is better to replace it with a new one to ensure the tightness of the combustion chamber.
How long does it take to replace all spark plugs?
With experience and the right tools, replacing all 6 spark plugs takes between 45 minutes and 1 hour. For a beginner without experience, this process may take 1.5–2 hours, especially if it requires cleaning the spark plug wells and removing stuck parts.