Engine cooling system Nissan Murano the second generation (Z51 body) is a complex engineering unit, the serviceability of which directly affects the life of the power unit. The central element of this system is water pump, ensuring the circulation of antifreeze through the radiator, cylinder block and interior heater. Owners of crossovers are often faced with the fact that after a mileage of about 100-120 thousand kilometers, the service life of the standard pump comes to an end, which requires immediate intervention.
Ignoring signs of malfunction can lead to overheating, deformation of the cylinder head and costly major repairs. For series engines QR25DE and VQ35DE, installed on this model, are characterized by specific problems with bearings and seals. It is important to recognize the symptoms in time in order to avoid critical situations on the highway or in a traffic jam.
Design features of the pump for Nissan Murano Z51
In car design Nissan Murano The Z51 water pump is made as a single unit, which is driven from the crankshaft through a timing belt. This means that when replacing the camshaft belt necessarily you need to inspect (check) or immediately change the pump itself. The pump body is made of aluminum alloy, which provides good heat transfer, but makes it vulnerable to electrochemical corrosion when using low-quality antifreeze.
Installed inside the case bearing and an impeller (impeller). For V6 engines (VQ35DE), the load on the unit is much higher than for in-line “fours” (QR25DE), so wear occurs faster. The impeller axis is sealed with an oil seal, which over time loses its properties under the influence of high temperatures and pressure. Coolant leakage through the oil seal is the most common failure scenario.
The manufacturer sets a certain resource, but actual operation under the conditions of our roads and climate often shortens this period. Particular attention should be paid to the assembly quality of the unit: distortions during production can lead to shaft runout and rapid destruction of the bearing. It is also worth noting that access to the pump on the engine VQ35DE limited due to the tight layout of the engine compartment.
Main symptoms of malfunction and diagnostic methods
The problem can be identified at an early stage by a number of indirect and obvious signs. The first “signal” is often extraneous noise from the engine compartment, which has a characteristic howl or hum that increases with increasing engine speed. This sound occurs due to wear of the rolling bearing, inside of which play appears and the tracks are destroyed.
The second critical symptom is the appearance smudges coolant. On Nissan Murano Z51 antifreeze may leak through the drain hole under the pump shaft or through the housing gasket. If you notice a puddle under the car after parking or traces of dried white/pink residue on the pump body, this is a sure sign of a leak.
- 🔊 A characteristic howl or hum from the timing belt area when the engine is running
- 🌡️ Increase in coolant temperature above normal in traffic jams
- 💧 The appearance of antifreeze stains under the car or on the pump body
- 🌀 Shaft runout when checking play by hand (with the belt removed)
Sometimes the problem manifests itself in the form of engine overheating only under certain operating conditions, for example, when driving uphill or at high speeds. This is due to the fact that a worn impeller cannot provide a sufficient volume of fluid pumping. In such cases, the radiator fan may operate at maximum speed constantly, creating a lot of noise.
⚠️ Attention: Do not try to add antifreeze and continue driving if you notice obvious noise from the pump or severe overheating. This can cause the engine to seize within minutes.
Consequences of ignoring pump problems
Neglect of diagnosis and timely replacement water pump on Nissan Murano Z51 has serious consequences. If the bearing fails completely, the shaft can become dislodged and damage the timing belt. For engines VQ35DE and QR25DE This is a catastrophic scenario: if the valve belt breaks, the valves collide with the pistons, leading to distortion of the valves and possibly destruction of the piston group.
Even if the belt does not break, antifreeze leakage will lead to a decrease in the fluid level in the system. This causes air pockets to form that block circulation. As a result, local overheating occurs, which can lead to burnout of the cylinder head gasket (cylinder head). Replacing the cylinder head gasket with Nissan - a labor-intensive and expensive procedure that requires the removal of many nodes.
In addition, leaking antifreeze can contact the timing belt, causing it to swell and lose elasticity. This accelerates the wear of all attachments driven by this belt. Complete pump failure on a VQ35DE engine in 90% of cases results in a major engine overhaul. Therefore, preventive replacement after a mileage of 100,000 km is an economically justified measure.
- Less than 100,000 km
- 100-150,000 km
- More than 150,000 km
- I'm planning to buy a high mileage one
DIY pump replacement process
Replacing the pump with Nissan Murano The Z51 is a technical challenge that requires some experience and a range of tools. Work must be carried out on a cold engine, after draining the coolant from the radiator and cylinder block. Accessing the pump on a VQ35DE engine often requires removing the top of the intake manifold and some accessories.
The first step is to remove the timing belt. This requires the use of special tools to secure the crankshaft and camshafts. If you are not confident in your abilities, it is better to entrust this stage to professionals. An error in setting the valve timing will result in engine inoperability. After removing the belt, unscrew the bolts securing the pump to the cylinder block.
- 🔧 Be sure to use a torque wrench to tighten the pump bolts
- 🧼 Carefully clean the adjacent surface of the block from old sealant
- 🛠️ Check the condition of the timing belt teeth before installing a new one
- 💧 Prepare new antifreeze for filling and removing air pockets
When installing a new pump, it is important not to overtighten the mounting bolts, as the aluminum body cracks easily. The recommended tightening torque is usually about 10-12 Nm, but it is better to check the instructions. After assembly, it is necessary to fill the cooling system and start the engine, monitoring the fluid level and the absence of leaks. The process of removing air from the system may take several warm-up and cool-down cycles.
☑️ Preparing to replace the pump
Before starting work, be sure to remove the terminal from the battery to avoid a short circuit if the tools accidentally come into contact with the wiring.
Selection of original spare parts and high-quality analogues
In the spare parts market for Nissan Murano There are many Z51 offerings, but not all of them are of equal quality. Original pump Nissan (catalog number often starts with 21010- or 21020-) is characterized by high quality casting, a reliable oil seal and a balanced impeller. This guarantees long service life and absence of vibrations.
However, original spare parts are not cheap, and many car owners are looking for worthy analogues. There are a number of manufacturers that supply pumps to the assembly line or have high reliability ratings. Among them are brands GMB, Aisin and SKF. These companies use the same production technologies as the original, but offer products at a more affordable price.
When choosing an analogue, you should avoid the cheapest offers from unknown brands. Cheap pumps often have a plastic impeller, which can become deformed due to temperature, or a low-quality oil seal that will begin to leak after 10-15 thousand kilometers. Always check the manufacturer's markings and the quality of the packaging.
| Manufacturer | Impeller type | Average resource (km) | Approximate price |
|---|---|---|---|
| Nissan (Original) | Metal | 150 000+ | High |
| GMB | Metal | 120 000+ | Average |
| Aisin | Metal | 130 000+ | Average |
| Cheap analogues | Plastic/Low grade metal | 30 000 - 50 000 | Low |
How to distinguish an original from a fake?|Original Nissan packaging has a hologram, clear font and high-quality printing. The pump itself must have a laser engraved part number that matches what is listed in the catalog. The casting quality of the body must be perfect, without burrs and holes.-->
Recommendations for maintenance and prevention
To extend the life of your water pump, you need to regularly monitor the condition of the cooling system. Using high-quality antifreeze recommended by the manufacturer (usually liquids based on Long Life Coolant organic acids) prevents corrosion and scale deposits. Never mix antifreezes of different colors and chemical compositions.
Timely replacement of the timing belt also plays an important role. If the belt is overtightened, it puts excess stress on the pump bearing, accelerating wear. If the belt is loose, it may jump, causing the pump to malfunction. When replacing the belt, always inspect the pump for play and signs of leakage.
- 🔍 Conduct a visual inspection of the cooling system every 15,000 km
- 🧪 Change antifreeze strictly according to regulations (usually once every 4 years or 100,000 km)
- 🌡️ Monitor the temperature sensor readings on the dashboard
- 🛑 When replacing the timing belt, change the pump prophylactically, even if it is not leaking
⚠️ Attention
⚠️ Attention
If you use cheap water instead of antifreeze, corrosion inside the pump will begin within a few months, which is guaranteed to lead to its failure.
Cost of work and spare parts
The total cost of replacing a pump consists of the price of the part itself and the cost of labor. The original pump on Nissan Murano Z51 can cost from 15,000 to 25,000 rubles, depending on the type of engine (2.5 or 3.5 liters). High-quality analogues from trusted brands will cost 8,000 - 12,000 rubles.
The cost of work at the service center varies from 7,000 to 15,000 rubles, since the procedure takes a lot of time (from 4 to 8 hours). If you decide to change the pump yourself, you will save on work, but will waste time and effort. Don't forget to take into account the cost of consumables: gaskets, sealant, clamps and new antifreeze.
Sometimes it is advisable to replace not only the pump, but also the timing belt, rollers and tensioner if their service life is exhausted. This will save you the hassle of having to disassemble the engine again in the future. A comprehensive replacement of all components of the gas distribution and cooling system ensures maximum reliability for the next 100,000 km.
When purchasing a timing belt kit, it often includes a pump. Check the kit before purchasing, this can significantly save your budget.
How much does it cost to replace a pump at an official dealership?
At the official dealership Nissan the cost of work is usually higher than in specialized service stations. The estimated turnkey price (with spare parts and fluid) can reach 40,000 - 50,000 rubles. However, you receive a guarantee for work and the use of only original spare parts.
Is it possible to drive with a leaking pump?
Short-term - yes, if the antifreeze level in the expansion tank is normal and you constantly monitor it. However, this is risky: a sudden leak can lead to overheating and engine failure. It is better to fix the problem as soon as possible.
Do I need to change the pump when replacing the timing belt on a Nissan Murano Z51?
It is highly recommended to change the pump at the same time as the timing belt. Since access to the pump requires removal of the belt, re-disassembly after 50,000 km will cost the same as replacing the belt. Preventive replacement saves money and hassle in the long run.
What antifreeze is best to use?
For engines Nissan Original Nissan Long Life Coolant fluids (blue or red depending on the year of manufacture) are best suited. You can also use high-quality analogues based on carboxylate technologies (G12, G13), but be sure to check compatibility with aluminum cylinder blocks.