Engine V6 VQ35DE, installed on crossovers Nissan Murano first generation (Z50 body), is considered one of the most reliable units in its class. However, even such a durable power plant has vulnerabilities, and one of the key components of the ignition system is the coils. With a mileage of more than 100,000 km, owners often encounter unstable engine operation, which is directly related to the degradation of these elements. Understanding the principles of their operation and timely diagnosis allows you to avoid costly repairs to the cylinder head.
Ignition system in Nissan Murano Z50 built according to the “coil-on-plug” scheme. This means that each candle has its own individual ignition coil, which eliminates high-voltage wires and minimizes energy losses. Despite its apparent simplicity, the failure of one of these modules instantly affects the operation of the entire system, causing the mixture to misfire. Ignoring the symptoms can lead to catalytic converter failure and serious problems with the electronic engine control unit (ECU).
Main signs of a faulty ignition coil
The first signal that ignition coil started to fail, the indicator lights up Check Engine on the dashboard. In the case of the engine VQ35DE this is often accompanied by vibrations that are transmitted to the body, especially when idling. Owners notice that the car begins to “trouble”, that is, it works unevenly, with noticeable jerks when accelerating or even while stopping.
In addition to visual and tactile sensations, characteristic symptoms are:
- 🚗 Significant increase in fuel consumption due to incomplete combustion of the combustible mixture.
- 🚗 Difficulty starting the engine, especially in the cold season or after a long stay.
- 🚗 Loss of power: the car accelerates poorly and does not respond to pressing the gas pedal with the proper energy.
- 🚗 Unstable idle speed, which can fluctuate from 600 to 1200 rpm.
If you notice at least one of the listed signs, do not delay diagnosis. Misfire in one cylinder lead to unburned fuel entering the exhaust system. IN Nissan Murano Z50 This is especially dangerous for the expensive catalytic converter, which can melt from overheating.
⚠️ Attention: If the Check Engine light is flashing rather than staying on, the engine is in critical condition. In this case, stop driving immediately and call a tow truck to avoid irreversible damage to the engine and catalytic converter.
Ignition system diagnostics and error codes
To accurately identify the faulty cylinder, you must use an OBD-II diagnostic scanner. By connecting the device to the connector located under the steering column, you can read error codes that will indicate a specific problem. In the system Nissan The most common are the P0300 series of errors, which indicate random misfires.
More accurate diagnostics will show which cylinder is not working correctly. The codes look like P0301, P0302, P0303 and so on, where the last digit indicates the number of the problem cylinder. For example, error P0304 will indicate leaks in the fourth cylinder. It is important to understand that the error code itself does not always mean that the coil is broken.
Before you change ignition coil, other reasons must be excluded:
- 🔧 Malfunction itself spark plugs (electrode wear, carbon deposits).
- 🔧 Problems with the fuel injector (clogging or jamming).
- 🔧 Air leak in the intake manifold.
- 🔧 Low compression in the cylinder due to wear of the piston group.
The most reliable way to check is the permutation method. If you have a spare, working coil, you can swap the suspicious module and the module from the adjacent cylinder. After clearing the errors and starting the engine, if the error code moves to another cylinder, then the coil is at fault. If the code remains in the same place, the problem lies in the spark plug, wiring or mechanical part of the engine.
- P0300 (Random Missing)
- P030X (cylinder specific)
- P035X (coil circuit)
- No errors, but triples
Original and analogues: choosing the best spare part
When choosing ignition coils for Nissan Murano Z50 You should pay close attention to the manufacturer. Original parts are marked as Nissan and have a catalog number 22448-EB00A or modifications thereof. These products are distinguished by high quality insulation and stable characteristics throughout their entire service life, but their cost is significantly higher than their analogues.
There are many manufacturers on the auto parts market offering worthy alternatives. The most popular and trusted brands are Denso, NGK and Delphi. Products Denso Often supplied as original equipment to Nissan production lines, the quality of these reels is almost identical to the original ones. In this case, the price can be 20-30% lower.
Comparison table of popular reel options for VQ35DE:
| Manufacturer | Type | Average price (RUB) | Features |
|---|---|---|---|
| Nissan (OEM) | Original | 8 500 - 11 000 | Maximum reliability, long service life |
| Denso | Analogue (OEM) | 5 500 - 7 000 | Excellent quality, often goes to the conveyor |
| NGK | Analogue | 4 500 - 6 000 | Stable work, good availability |
| Delphi | Analogue | 3 500 - 4 500 | Budget option, average resource |
| Uncle/China | Chinese noname | 1 500 - 2 500 | Low quality, high risk of rapid failure |
Budget Chinese analogues often do not withstand even 20-30 thousand kilometers. Their insulation may burn out, and the magnetic field may not be sufficient for reliable sparking. Saving on such parts often leads to the fact that after a couple of months you have to buy the coil again and pay for the replacement work, which ultimately ends up being more expensive than buying a quality brand outright.
⚠️ Attention: When purchasing a reel, be sure to check the integrity of the plastic case and the absence of signs of burning on the electrical connector. Even microcracks can lead to breakdown of the housing under high humidity.
Buy coils as a set if the mileage of your Murano Z50 exceeds 150,000 km. Often wear occurs evenly, and replacing one part will lead to the rapid breakdown of the next one after a couple of thousand kilometers.
Step-by-step instructions for replacing the coil
Replacement ignition coils on the engine VQ35DE does not require complicated removal of units, but access to some cylinders may be difficult due to the design features of the engine compartment. The process takes from 40 minutes to an hour with a basic set of tools. You will need 10 mm socket wrenches, an 8 mm socket for spark plugs and a ratchet with an extension.
Before starting work, it is necessary to de-energize the vehicle by disconnecting the negative terminal of the battery. This will prevent accidental short circuits and airbag deployment. Removing the decorative plastic motor cover is also required to gain access to the upper parts of the coils.
Checklist for successful replacement:
☑️ Preparation for replacement
The algorithm of actions is as follows:
- 🛠️ Disconnect the electrical connector from the faulty coil by gently pressing the latch.
- 🛠️ Unscrew the two mounting bolts holding the module to the cylinder head.
- 🛠️ Pull the coil out of the well by pulling up with a little force. Be careful not to damage the rubber O-ring.
- 🛠️ Clean the seat from dirt and carbon deposits to prevent debris from entering the cylinder.
Before installing a new part, it is recommended to lubricate the inside of the rubber cap with dielectric grease. This will improve contact, prevent the coil from sticking to the spark plug and protect against breakdown. Install a new one reel, tighten the fastening bolts and connect the connector until it clicks.
Features of access to the rear coils
The rear coils (cylinders 4, 5, 6) are located under the intake manifold. To replace them, it is often necessary to remove the throttle assembly and inlet pipe, which greatly complicates the procedure. It is recommended to change them only if you have experience or at a service station.
⚠️ Attention: Never try to pull out the coil without unscrewing the mounting bolts. Plastic case Nissan Quite brittle at low temperatures and may crack, requiring the purchase of a new part.
Common mistakes when servicing the ignition system
Many owners Nissan Murano Z50 make typical mistakes that shorten the life of new reels. One of the most common is the use of low-quality spark plugs. Coil works in tandem with the spark plug, and if the spark gap is too large or the electrode has defects, the coil operates in overload mode. This leads to rapid failure of the module.
Another critical mistake is ignoring the state of the connector. Over time, the contacts oxidize, which increases resistance and causes heat. If you notice burnt or oxidation on the contacts, they need to be cleaned or the entire connector replaced. Trying to simply insert a new coil into an old rotten connector is doomed to failure.
It is also important to observe the tightening torque of the fastening bolts. Excessive force can damage the threads in the cylinder head, and weak tightening will lead to vibrations and poor contact. Use a torque wrench if possible, or tighten the bolts until they are tight without applying excessive force.
Compliance with the regulations for replacing spark plugs and the use of high-quality consumables extends the life of ignition coils by 2-3 times compared to non-systemic maintenance.
Influence of fuel quality and driving style
The operation of the ignition system directly depends on the quality of the fuel mixture. The use of low octane gasoline or the presence of impurities in the fuel can lead to detonation and unstable combustion. Nissan Murano Z50 with engine VQ35DE designed for fuel not lower than AI-95. Filling AI-92 can provoke early ignition, which creates additional load on the coils.
Driving style also plays a role. Aggressive driving with constant hard acceleration and high engine speeds forces the coils to work to the limit of their capabilities. If you use kick-down mode frequently, the lifespan of the modules may be reduced. In such conditions, it is recommended to carry out more frequent diagnostics of the ignition system.
In addition, temperature conditions of operation have an impact. In harsh winter conditions and frequent cold engine starts, the coils experience thermal shock. Proper operation of the engine cooling system also indirectly affects the reliability of the ignition elements, since engine overheating accelerates the degradation of insulating materials.
FAQ: Answers to frequently asked questions
Is it possible to drive with a faulty ignition coil?
Technically possible, but highly not recommended. Driving with a misfire leads to overheating of the catalyst, which can break down and clog the exhaust system. This also causes unstable engine operation and increased wear of other components.
Do I need to change all the coils at once or just one?
If one coil fails after a mileage of more than 100,000 km, it is recommended to replace everything at once or at least a set for one side of the engine. They have approximately the same resource, and the rest may soon fail, which will require repeated disassembly.
How to check a coil with a multimeter?
Testing with a multimeter only gives an approximate picture. It is necessary to measure the resistance of the primary and secondary windings and compare them with the manufacturer’s passport data. However, a multimeter cannot always detect an interturn short circuit, which only appears under load.
Why does the error not disappear after replacing the coil?
The error may be stored in the ECU memory. It is necessary to erase error codes with a scanner. If the error returns immediately, check the serviceability of the spark plug, wiring or the presence of air leaks in this cylinder.