Withdrawal procedure intake manifold on cars Nissan This generation has its own design features that differ from older models. The key point is proper access to fasteners, many of which are hidden under decorative overlays and additional components. Without careful preparation and understanding of the sequence of actions, you can damage fragile plastic pipes or break sensors.
In this article we will analyze the dismantling algorithm in detail, focusing on the specifics of the engine compartment Almera. You'll learn what tools you'll need to get the job done, how to safely turn off the electrics, and what to pay special attention to when reassembling.
Preparing the workplace and tools
Before starting any physical impact on vehicle components, it is necessary to create comfortable working conditions. Engine HR15DE Mounted in a cramped engine compartment, access to the top of the manifold may be limited. You will need a good light source and the ability to move your arms freely around the engine.
To carry out the work, a standard mechanic's kit is required, but taking into account the specifics of Japanese cars. Particular attention should be paid to heads and collars, since bolts often stick to the threads due to high temperatures. Using a high-quality thread lubricant during disassembly will greatly simplify subsequent assembly.
- 🔧 Set of socket heads (from 8 to 14 mm) and extensions
- 🔧 Screwdrivers with flat and Phillips blades (medium and small sizes)
- 🔧 Pliers or a puller for clamps on pipes
- 🔧 A can of brake cleaner or carb cleaner
It is also extremely important to have a container ready to drain the coolant if you plan to remove radiator hoses that cross the intake tract. Do not forget about rags and bags for marking the removed connectors and bolts, so as not to mix them up during assembly.
Disabling electrical power and dismantling attachments
The first step is always to de-energize the system and remove components that interfere with access to the collector. On Nissan Almera this involves removing the decorative plastic engine cover, which is secured with rubber clips. Just pull it up, but be careful not to break the latches.
The next step is to disconnect all electrical connectors connected to the sensors on the manifold. These are the throttle valve, absolute pressure sensor (MAP sensor) and idle air control. When disconnecting, press the connector latch and do not pull the wires, otherwise you may break the contact group.
- 🔌 Disconnect the negative battery terminal for safety
- 🔌 Remove the throttle assembly (after unscrewing the 4 mounting bolts)
- 🔌 Disconnect the connectors from the throttle position and pressure sensors
After removing the electrics, it is necessary to remove the vacuum hoses and pipes of the crankcase ventilation system. They often stick to plastic fittings, so it is better to gently rock them, prying them up with a flat screwdriver so as not to damage the seats.
Features of unscrewing mounting bolts
The fasteners for the intake manifold itself are made of steel, but the cylinder head is made of aluminum, which requires special care when unscrewing. The bolts are tightened to a certain torque, and during prolonged use they can become sour. Do not use excessive force to avoid stripping the threads in the cylinder head.
It is important to follow the correct unscrewing sequence. This is usually a diagonal pattern, starting at the edges and moving toward the center to avoid skewing the commutator housing and damaging it. If the bolt does not budge, use a penetrating lubricant and give it time to work.
☑️ Checking the condition of the fasteners
- 🔩 Inspect the bolts for corrosion and damage to the threads
- 🔩 Use a wrench with an extension to access the distant bolts
- 🔩 Don’t forget about the bolts securing the thermal protection bracket
Sometimes there may be bolts for mounting brackets for the generator or other attachments under or near the manifold, which prevent complete dismantling. In such cases, it may be necessary to temporarily remove these units to obtain free movement.
Removing pipes and vacuum system
Intake system Almera G15 Integrated with multiple vacuum lines and air hoses. Most of them are mounted on plastic clamps, which become brittle over time. When removing them, it is better to replace them with new ones, since old ones often crack during dismantling.
Pay special attention to the crankcase ventilation system pipe, which comes from the valve cover. It has a complex shape and sits tightly on the manifold fitting. When removing it, do not pull sharply, but carefully turn it around the axis so as not to break the plastic fitting.
⚠️ Attention: When disconnecting vacuum tubes, be sure to mark their location, as it is very easy to confuse them, which will lead to unstable engine operation.
It is also necessary to remove the pipe coming from the air filter to the throttle body if it interferes with the removal of the manifold. Usually it is attached to one clamp and has a rubber insert that hardens over time.
- Cleaned it yourself
- Contacted the service
- Never filmed
- Just changed the gaskets
Removing the intake manifold from the engine compartment
After all fasteners, hoses and connectors have been disconnected, you can begin to directly remove the assembly. Collector on HR15DE It has significant weight and volume, so removing it requires care so as not to touch adjacent parts.
Start by gently rocking your body to get it out of place. If it does not budge, check again that all pipes and bolts have been removed. Often the cause of a jam is a bracket that is not unscrewed or a vacuum hose that is caught.
- 🚗 Carefully lift the collector up, following the exit path
- 🚗 Be careful not to damage the cylinder head gasket (it is disposable)
- 🚗 Remove the assembly from the engine compartment towards the radiator or up
When removing, be prepared for the possibility that some condensate or oil may leak out of the manifold. Cover the area under the engine with a rag or cardboard to avoid staining the body and garage floor.
What to do if the collector is stuck?
If the manifold cannot be removed due to the gasket sticking, do not try to pry it off with a pry bar, as you may damage the surface of the cylinder head. It is better to use a special lubricant and give it time to penetrate the joint, and then gently rock the body from side to side.
Cleaning and preparation for reinstallation
After removing the assembly, it is necessary to thoroughly clean the seats on the cylinder head. The old gasket must be removed completely, without any residue. Use a scraper made of soft metal or plastic to avoid scratching the aluminum surface.
The collector itself also requires cleaning from carbon deposits, oil and dirt. A carburetor cleaner is great for this, as it effectively removes even old deposits. Wipe the internal channels and check the condition of the valves (if any).
⚠️ Attention: It is strictly forbidden to use abrasive materials or metal brushes to clean the contact surface of the commutator with the cylinder head, as this will break the seal.
Be sure to replace the manifold gasket with a new one. An old gasket will no longer provide proper tightness and can lead to air leaks, which will cause an error in the mixture. Also check the condition of the sensors on the manifold and replace them if necessary.
Before installing a new gasket, apply a thin layer of high-temperature sealant to the gasket where it interfaces with the sensors and vacuum fittings for additional tightness.
Checking the system after assembly
Reassembly is carried out in the reverse order of disassembly. It is important to observe the tightening torque of the bolts so as not to deform the collector body. Use a torque wrench and tighten the bolts in a crisscross pattern.
After assembly, it is necessary to check the tightness of all connections. Start the engine and listen carefully to the idle speed. Any unusual noises or whistles may indicate a loose gasket or damage to the hose.
- ✅ Check for errors on the dashboard
- ✅ Make sure the idle speed is stable
- ✅ Inspect the pipes for leaks or kinks
If you removed the battery or disconnected the electrical system, the throttle body may need to be adjusted. This is done by warming up the engine to operating temperature and then turning off the ignition for 30 seconds.
High-quality cleaning and replacement of the gasket is the key to stable engine operation and the absence of mixture errors in the future.
Frequent mistakes and recommendations from experts
Many owners Nissan Almera make typical mistakes when servicing themselves. One of the most common is to use a sealant instead of a gasket. This can cause clogged passages and damage the engine.
Another mistake is not tightening the bolts correctly. Too much force can strip the threads, and too little force can lead to air leaks. Always use a torque wrench and follow the manufacturer's specifications.
How to check for leaks without starting?
You can use a can of cleaner or foam. Spray the product liberally around the manifold joint when the engine is cold. If the speed changes or the foam starts to bubble, it means there is an air leak.
It is also worth paying attention to the condition of the vacuum tubes. If they become tanned and cracked, it is better to replace them immediately to avoid problems in the future.
⚠️ Warning: When working with a hot engine, there is a risk of burns. Wait until the engine has completely cooled before starting work, especially if you plan to remove the coolant pipes.
Remember that regular intake tract cleaning prolongs engine life and saves fuel. Don't ignore signs of contamination such as rough acceleration or increased consumption.
Save the old set of gaskets and bolts in a bag and put them in the trunk. In the event of an emergency breakdown or the need for repeated dismantling, this will save you time and money.
FAQ: Answers to frequently asked questions
Do I need to drain the antifreeze before removing the manifold?
On most versions Nissan Almera G15 The cooling system pipes do not directly cross the manifold, so draining the antifreeze is not required. However, if you plan to remove the bypass hoses, it is better to drain the fluid to avoid flooding the engine.
How long does it take to remove the manifold?
For an experienced master, the procedure takes about 1.5–2 hours. If this is your first time, allow 3-4 hours, including time to study the instructions and find tools.
Can I use sealant instead of gasket?
No, it is not recommended to use sealant instead of gasket. This could cause sealant to leak into the intake and damage the engine. Always use the stock gasket.
How can I check that the manifold is installed correctly?
After starting the engine, check for whistles and air leaks. Also, there should be no mixture errors on the diagnostic scanner (for example, P0171 or P0174).
Is it necessary to adapt the throttle valve?
Yes, after disconnecting the battery or removing the throttle assembly, it is recommended to carry out the adaptation procedure. This is usually done by warming up the engine and turning off the ignition for 30 seconds.