Step-by-step removal of the valve cover on Nissan Almera N16: instructions with photos and nuances

Nissan Almera N16 — a popular sedan with a reliable engine QG15DE (1.5 l) or QG18DE (1.8 l), but even such engines require maintenance over time. One common procedure is removing the valve cover to replace the gasket, check the camshafts, or fix an oil leak. It would seem like a simple operation, but without knowing the nuances you can encounter problems: from breaking plastic elements to dirt getting into the engine.

In this article you will find detailed instructions with photos, a list of necessary tools, as well as unique tips for working with cover fastenings on Almera N16 - for example, how to properly disconnect the crankcase ventilation system pipes without damaging them. We will also analyze common mistakes that even experienced car owners make and give recommendations on choosing a gasket.

Preparing for work: tools and materials

Before you begin dismantling, make sure you have everything you need. The absence of even one tool can delay the process for hours. Here's the full list:

• 🔧 A set of sockets with a ratchet (a head on the 10 mm)
• 🔨 Screwdriver with flat and Phillips blade (for clamps and clamps)
• 🧲 Magnetic holder or tweezers (for removing fallen nuts)
• 🧴 Sealant for gaskets (for example, Loctite 574 or ABRO 11-AB)
• 🧽 Lint-free rags and carburetor cleaner (for cleaning surfaces)
• 🔄 New valve cover gasket (original Nissan 11044-JA00A or analogues Elring, Victor Reinz)

Pay special attention to the choice of gasket. Original parts from Nissan They last longer, but are more expensive. Alternative brands (eg. Goetze or Corteco) can fail after 30–50 thousand km, especially if the engine often operates at high speeds. Also prepare plastic scraper to remove old sealant - a metal tool scratches the aluminum surface of the block head.

Removing the battery terminal and preparing the work area

The first step is to de-energize the car. This is not only safety, but also protects the electronics from short circuits if you accidentally touch the wires. Disconnect the negative battery terminal (key to 10 mm) and take it aside. Some technicians recommend removing both terminals, but one is enough for this procedure.

Next, prepare your work area:

• 🚗 Place the car on a flat surface, lock the handbrake and engage first gear (or P on automatic transmission).
• 🔥 Allow the engine to cool to below 40°C - hot oil can burn and the plastic parts of the cover become brittle.
• 🧹 Remove debris and dust from the top of the engine to prevent dirt from getting inside after removing the cover.

If you work in a garage, use portable LED lamp — standard lighting often does not allow you to see small details, for example, cracks in ventilation pipes. Also prepare plastic bag And elastic band - they can be used to close open holes after removing the cover to prevent foreign objects from entering.

Removing air ducts and crankcase ventilation pipes

Valve cover on Almera N16 It is closed not only with fastenings, but also with a crankcase ventilation system. Improperly disconnecting the pipes can lead to their rupture - this is especially true for old plastic, which hardens over time. Let's start with the air duct:

1. Loosen the clamps on air filter And throttle assembly (screwdriver or head on 8 mm).
2. Remove the corrugated pipe going from the filter to the throttle. Be careful as condensation may accumulate inside.
3. Disconnect thin ventilation hose (usually black) that goes from the valve cover to the air duct.

Now let's move on to the crankcase ventilation pipes. There are two of them:

• 🔄 Large pipe (diameter ~20 mm) - connects the cover to the oil separator.
• 🔄 Small pipe (diameter ~10 mm) - goes to the intake manifold.

To remove them, first squeeze the plastic clips (they break often, so it's best to buy spares in advance). If the pipes are stuck, do not pull by force - water the connections WD-40 and wait 5-10 minutes. On Almera N16, the small pipe often cracks during dismantling, so it is better to replace it in advance (original article number - Nissan 11770-4M000).

What to do if the pipe clamp is broken?

If the plastic retainer is cracked, you can temporarily secure the pipe with a tie or wire, but it is better to replace it with a new one. As a last resort, use a heat-shrinkable tube of the appropriate diameter, heating it with a hair dryer.

Unscrewing the valve cover fastenings: order and nuances

Valve cover on Almera N16 fastened 15 bolts (on some modifications - 14). They are located around the perimeter and have different lengths, so it is important to remember which bolt was removed from where. Use the diagram below:

Bolt number	Length (mm)	Location	Tightening torque (Nm)
1–4, 10–13	25	On the corners and sides	8–10
5–9, 14	40	Central (near camshafts)	8–10
15	15	Near the oil filler neck	6–8

Unscrewing order: start with central bolts (5–9, 14) and move towards the edges. This will help to evenly relieve pressure from the gasket and avoid its deformation. Use the head on 10 mm with extension cord - access is limited in some areas. If the bolt does not budge, do not apply excessive force: Almera N16 The threads in the aluminum block head are easily stripped.

After unscrewing all the bolts, carefully pry the cover with a flat-head screwdriver plastic nozzle (so as not to scratch). Let's start from the corner 近 of the oil filler neck - there the gasket usually “comes off” first. If the lid is stuck, do not try to tear it off: water the joint penetrating lubricant and wait 15–20 minutes.

Bolts are unscrewed in the correct order|Vent pipes are disconnected|Battery terminal is removed|Work area is cleared of debris|Bag bags are prepared to cover the holes-->

Removing the cover and inspecting the internal elements

When the cover has separated from the block head, carefully lift it vertically so as not to damage it. valve stem seals And camshafts. On Almera N16 oil often accumulates under the cap in the area VTC (variable valve timing system), so be prepared for it to leak. Place the lid on a clean surface upside down - this way you will avoid dirt getting inside.

Now check:

• 🔍 Gasket condition - if it is oak or has cracks, replacement cannot be avoided.
• 🔍 Camshafts and cams - there should be no scoring or wear.
• 🔍 Valve seals - if they are covered with oil on top, this is a sign of wear.
• 🔍 Ventilation channels — clogged holes lead to increased crankcase gas pressure.

Please note oil in the lid: if it is black with metal shavings, this is a signal about problems with the oil pump or camshaft bearings. In this case, a more in-depth diagnosis will be required. Also check condition of o-rings under the cover bolts - they often lose their elasticity and need to be replaced (article number Nissan 11045-JA00A).

Cleaning surfaces and installing a new gasket

Before installing a new gasket, it must be thoroughly cleaned. seating surfaces on the cover and head of the block. Use plastic scraper And carburetor cleaner (For example, HI-GEAR HG3210). Do not use sandpaper or metal brushes - they will leave scratches that will later lead to oil leakage.

Cleaning algorithm:

1. Remove old sealant from the cover and head.
2. Wipe the surfaces with a cloth soaked in gasoline or acetone.
3. Blow out the crankcase ventilation ducts with compressed air (clogged ducts are a common cause of gasket leaks).
4. Apply a thin layer of sealant to cover corners (not on the gasket!).

When installing a new gasket, make sure that:

• ✅ It lay flat, without distortions (the holes must match the guides).
• ✅ The O-rings under the bolts were in place.
• ✅ The sealant did not get inside the engine (remove excess immediately).

On Almera N16 often make the mistake of applying sealant to the entire gasket, which is why later it “floats” and blocks the oil channels. It is enough to process only corners and joints! Also, do not tighten the bolts immediately - let the sealant dry for 10-15 minutes.

Assembly and leak testing

Installing the cover is performed in the reverse order, but taking into account several nuances:

1. Start with hand tightening all bolts (without a ratchet!) in the reverse order of removal.
2. Tighten the bolts criss-cross in 2-3 approaches so that the gasket sits evenly.
3. Use torque wrench with the moment 8–10 Nm (for oil filler neck bolt 近 - 6–8 Nm).

After assembly:

• 🔧 Connect all pipes and check the clamps.
• 🔋 Connect the battery terminal.
• 🚗 Start the engine and let it idle for 5-10 minutes.
• 🔍 Inspect the joint of the lid for oil leaks.

If after starting the engine you hear extraneous noise (knocking or rustling sound), turn off the engine immediately. This may mean that a foreign object has entered the cover or the gasket has become dislodged. Also check oil pressure — if the lamp on the dashboard blinks for more than 3–5 seconds, the oil receiver may be clogged.

FAQ: Frequently asked questions about removing the valve cover on Almera N16

Can I reuse an old gasket?

No, even if visually it looks intact. The rubber loses its elasticity after the first crimp, and when reinstalled, the gasket will not provide a tight seal. The exception is temporary repairs in the field, but in this case use sealant on both sides.

What should I do if after assembly oil leaks from under the cap?

The reasons may be as follows:

• Uneven tightening of bolts (need to be tightened with the correct torque).
• The seating surface of the cylinder head is damaged (needs to be ground).
• The gasket is defective (replace with the original).
• The crankcase ventilation ducts are clogged (clean them).

In 80% of cases, the problem is solved by reassembly, observing the tightening torque.

Do I need to use sealant if the gasket is new?

On Almera N16 The manufacturer recommends applying sealant only on the corners of the lid, even with a new gasket. This is due to the design of the engine: oil often accumulates in the corners, and additional sealing prevents leaks. For other areas, sealant is not necessary if the gasket is of good quality.

How often should the valve cover gasket be replaced?

Regular replacement period - every 100–120 thousand km, but in practice it depends on the operating conditions:

• If the engine overheats frequently - every 60–80 thousand km.
• When using low-quality oil - every 50–70 thousand km.
• When driving aggressively (high revs) - every 80–100 thousand km.

Also, the gasket is changed when any removal of the cover, even if it is outwardly intact.

Is it possible to drive with an oil leak from the valve cover?

Short-term - yes, but it is fraught with consequences:

• Oil will get on Timing and alternator belts, reducing their resource.
• Oil consumption will increase, which will lead to oil starvation.
• If the leak is severe, oil may get onto exhaust manifold and catch fire.

If the leak is small (drops at the junction), you can go to a service station, but it is better to fix the problem right away.