Exhaust system on a crossover Nissan Murano the second generation (Z51 body) is a complex engineering solution that combines environmental standards and requirements for engine dynamics. Over time, especially under conditions of aggressive operation and the use of low-quality fuel, the corrugated section (flexible element) of the front muffler becomes a critical element. This is where the maximum vibration load from the operation of the motor occurs, transmitted to the rigid pipeline.
Ignoring the first signs of corrugation destruction can lead to serious consequences: from toxic gases entering the cabin to failure of lambda probes and catalytic converter. Replacing corrugations on Nissan Murano Z51 - this is not just a cosmetic repair, but a necessity to preserve the life of the power unit and the correct operation of the engine control system.
Symptoms of malfunction and initial diagnosis
You can determine that the corrugation requires urgent replacement by several characteristic symptoms that are dangerous to ignore. The most obvious sign is the appearance of extraneous sounds, reminiscent of crackling or knocking, especially when starting a cold engine or sharply pressing the gas pedal. These sounds occur due to a leak in the connection through which high-pressure gases escape.
In addition to acoustic signals, pay attention to the operation of the engine. If you notice that no power, fuel consumption has increased or the Check Engine light has come on, the problem may be due to air leaks in the exhaust system. Oxygen sensors installed before and after the catalyst receive incorrect data due to the disrupted geometry of the exhaust gas flow.
A visual inspection under the vehicle will reveal the most obvious defects. Often the owner notices traces of soot around the joints of the corrugation or the most flexible element. In some cases, the rupture is visible to the naked eye, especially if the metal has already been severely thinned by corrosion. However, sometimes the cracks are so small that gases only escape under load, so a thorough inspection is required.
⚠️ Attention: If you hear a hissing or knocking sound from underneath while warming up, immediately stop using the vehicle until diagnostics are carried out. Exhaust gases entering the cabin through the ventilation system can lead to carbon monoxide poisoning.
Choosing quality spare parts for Murano Z51
The auto parts market offers a huge range of corrugations, but the quality of materials varies widely. For Nissan Murano Z51 With a 3.5L V6 engine (VR35DE), it is critical to select stainless steel products that can withstand high temperatures and harsh environments. Ordinary steel quickly oxidizes and deteriorates, which will lead to repeated repairs within a few months.
Pay attention to the design of the flexible element. There are two main types: woven and spiral corrugation. The braided design is more resistant to vibration and stretching, making it ideal for a crossover front muffler. Spiral corrugation is cheaper, but it is less reliable at high temperatures and can quickly lose elasticity.
- 🔍 Check the thickness of the corrugation walls - for a 3.5 l engine it should be at least 1.2 mm.
- 🛡️ Make sure you have a quality certificate and warranty from the manufacturer of the spare part.
- 🔧 Please note that the kit includes flanges or clamps for easy installation.
You should not save on this element, since the cost of replacement work often exceeds the price of the part itself. Installing a low-quality corrugation will result in you having to lift the car onto the lift again. Original spare part or a high-quality analogue from trusted brands (for example, Bosal or Walker) will ensure the durability of the repair.
- Braided stainless steel
- Spiral steel
- Original from the dealer
- Budget analogue
Necessary tools and preparation for work
Before starting work, make sure that you have all the necessary tools. Repairing the exhaust system requires access to the bottom of the car, so an inspection hole or lift is required. Working in a garage without an overpass is extremely inconvenient and dangerous. In addition, you will need hand and eye protection against rust and dirt.
The list of required tools includes: a set of socket heads and wrenches, wrenches for unscrewing clamps, penetrating lubricant (such as WD-40 or equivalent), an angle grinder with a metal disc and a welding machine (preferably argon-arc). If there is no welding, you can use special clamps, but their reliability is lower.
☑️ Tools for replacing corrugations
Pay special attention to the preparation of threaded connections. The bolts securing the manifold and muffler flanges often become tightly stuck due to high temperatures and exposure to reagents. Spray them liberally with lubricant and let sit for at least 15-20 minutes. Trying to unscrew them without preparation will cause the threads to break, which will complicate repairs.
⚠️ Attention: Do not use an open flame to heat stuck bolts near fuel lines and the fuel tank. Use only specialized chemicals for thread decarbonization.
Step-by-step instructions for dismantling and installation
The replacement process begins with dismantling the old corrugation. First you need to unscrew the clamps securing the front muffler to the exhaust pipe and manifold. If the bolts do not budge, you can carefully cut them off with a grinder, but do this extremely carefully so as not to damage the threads on the manifold flanges. Collector - this is an expensive element that you don’t want to change.
After removing the old element, clean the flange surfaces from carbon deposits and rust. This will ensure the new connection is tight. If there are cracks or deformations on the collector, they must be repaired before installing a new corrugation. Install a new corrugation, first applying heat-resistant sealant to the flanges.
Tighten the clamps evenly, alternating sides to avoid distortion. If welding is used, the seam must be continuous and welded on both sides. Seam quality directly affects the service life of the corrugation and the absence of vibrations. After installation, check that all elements are securely fastened.
What to do if the flanges don't match?
If, after removing the old corrugation, you notice that the flanges do not match due to deformation or improper installation, do not try to force them together with clamps. This will lead to rapid destruction of the new part. In this case, it is necessary to either bend the flanges or use an adapter that compensates for the difference in geometry.
Rubber muffler hangers must operate normally, compensating for thermal expansion and vibration. If the corrugation is installed in tension, it will quickly fail.
Correct installation of the corrugation eliminates any mechanical stress on the metal; all loads must be absorbed by rubber hangers and the elasticity of the corrugation itself.
Comparison of repair options and their costs
Many car owners are wondering: what is more profitable - replacing only the corrugation or buying the entire assembly? Replacing only the flexible element is cheaper, but requires more time and skilled technicians. Purchasing a new assembly (front muffler with corrugation) simplifies the process, but costs much more.
Let's look at a table comparing repair options for Nissan Murano Z51:
| Repair option | Complexity of work | Approximate cost | Service life |
|---|---|---|---|
| Replacing only the corrugations | Average | Low | 2-3 years |
| Replacing the assembly | Low | High | 5-7 years |
| Welding old corrugation | High | Very low | Up to 6 months |
The choice depends on your budget and the condition of the rest of the system. If the flanges and pipes are still in good condition, it makes sense to replace only the corrugation. If the pipes are rotten, it is better to install a new assembly to avoid repeated problems in the near future.
Before ordering a spare part, measure the length and diameter of the corrugation with a caliper, as there may be slight deviations in dimensions in different markets, which are critical during installation.
Nuances of operation after repair
Once work is completed, the sealant must be allowed to dry completely and harden before starting the engine. This usually takes from 1 to 4 hours depending on the type of composition used. Starting the engine immediately after installation may lead to a violation of the tightness of the seams.
For the first few days after repair, keep an eye out for sounds coming from underneath. If you notice a new noise or vibration, something may have been installed incorrectly. Vibration may be caused by improper alignment or missing gaskets. Do not ignore these signals, as they can lead to the destruction of other elements of the system.
Perform visual inspections of the exhaust system regularly. Cleaning the underbody of the car from reagents and dirt after winter will help extend the service life of not only the corrugations, but also other elements. Nissan Murano - a reliable car, but its exhaust system requires attention and care.
⚠️ Attention: Do not allow water to get on the hot corrugation immediately after a long trip. Sudden cooling can lead to the formation of microcracks in the metal due to thermal shock.
How to check the tightness of the system?
To check for leaks, you can use a soap solution. Apply it to all joints and seams with the engine running. The appearance of bubbles will indicate the location of the leak. This method is safe and effective for detecting small cracks.
Frequently asked questions and answers
Is it possible to replace the corrugation without welding?
Yes, you can use special heat-resistant clamps and gaskets, but the reliability of such a connection is much lower than when welding. Clamps can become loose over time due to vibration.
How long does it take to replace a corrugation?
If you have a lift and the necessary tools, replacement takes from 1.5 to 3 hours. If the bolts are stuck, the time may increase to 4-5 hours.
Do I need to change the flange gaskets?
Definitely yes. Old gaskets lose their elasticity and will not provide a tight seal. Use new copper or asbestos gaskets.
Does replacing corrugation affect the environmental class?
If the new corrugation is installed correctly and there are no leaks, the environmental indicators do not change. If there is air leakage, the lambda probe readings may be incorrect.
What should I do if the Check Engine light is on after replacement?
This may indicate a leak or the sensors are not working correctly. Check the system for leaks and, if necessary, reset errors using a diagnostic scanner.