Spark plugs for Nissan Almera G15: how to choose and replace correctly

Nissan Almera G15 - popular sedan with engine HR16DE (1.6 l), which, with proper maintenance, lasts hundreds of thousands of kilometers. But even the most reliable technology requires attention to detail - for example, spark plugs. Not only engine starting in cold weather, but also fuel consumption, acceleration dynamics, and, in the future, the service life of the catalyst and lambda probes depend on their condition.

In this article we will analyze unique nuances of selecting spark plugs specifically for Almera G15 (including restyled versions 2016–2019), we will tell you how to recognize fakes of the original NGK And Denso, and we will give step-by-step instructions for replacement with photos of key points. We will also reveal the myths about “eternal” iridium spark plugs and explain why they are not always worth installing.

Original spark plugs for Nissan Almera G15: articles and analogues

The manufacturer sets the Almera G15 There are two types of candles depending on the year of manufacture and market:

• 🔧 NGK IFR6T11 (article 22401-JM40A) - iridium, with a thin central electrode (0.6 mm). Installed on cars for Europe and Russia from 2013 to 2019.
• 🔧 Denso IXUH22I (article 22401-JM40B) - also iridium, but with a slightly different heat rating. Seen less frequently, mainly on Asian versions.

Both options are interchangeable, but it is important to check gap between electrodes - he must be 1.0–1.1 mm. On fakes this parameter is often inflated to 1.3 mm, which leads to misfires.

Manufacturer	Article	Type	Gap (mm)	Service life (km)
NGK	IFR6T11 / 22401-JM40A	Iridium	1.0–1.1	100 000
Denso	IXUH22I / 22401-JM40B	Iridium	1.0–1.1	100 000
Bosch	0 242 236 566	Iridium (analogue)	1.0	80 000–100 000
Beru	Z 322	Nickel (budget)	1.1	30 000–50 000

If original candles are difficult to find, you can use analogues from Bosch, Beru or Champion, but with a mandatory clearance check. For example, Bosch 0 242 236 566 fits the parameters, but has a slightly different insulator design - this is not critical, but can complicate the visual diagnosis of carbon deposits.

⚠️ Attention: On Almeria G15 with LPG (gas-cylinder equipment), the original iridium spark plugs last 1.5–2 times less due to the higher gas combustion temperature. In this case, it is recommended to set platinum coated spark plugs (For example, NGK LZFR6AP-11) or reduce the replacement interval to 50,000 km.

Signs of spark plug wear: when is it time to change

The manufacturer recommends replacing spark plugs with Almera G15 every 100,000 km (for iridium) or 30,000–50,000 km (for nickel). But in practice, this interval may be shortened due to low-quality fuel, driving short distances or problems with the ignition system. The following symptoms indicate that it is time to check the spark plugs:

• ⚡ "Trippling" of the engine at idle or during acceleration (especially noticeable when cold).
• 🛢️ Increased fuel consumption by 10–15% for no apparent reason (for example, from 6.5 l/100 km to 7.5 l/100 km).
• 🚗 Dips when accelerating, as if the car “jerks” when you press the gas.
• 🔥 Difficulty starting in cold weather (the starter turns, but the engine doesn’t “start” the first time).
• 💨 Black or gray smoke from the exhaust pipe (indicates misfire and incomplete combustion of fuel).

If you notice at least two of these signs, do not rush to buy new candles right away. First unscrew the old ones and inspect them:

• 🔍 Normal Wear: light gray or brown soot, no electrode erosion.
• 🛑 Oil soot (black and bold) - indicates problems with valve stem seals or piston rings.
• ⚡ Electrode erosion (sharp edges, increased clearance) - a sign of long-term operation or the use of low-quality fuel.
• 🔥 Melted electrodes - evidence of overheating (may be caused by incorrect heat rating or detonation).

If the candles are outwardly in order, but symptoms remain, check ignition coils (on Almere G15 they often fail) and high voltage wires. To diagnose coils, you can use a multimeter: the resistance of the primary winding should be within 0.5–1.0 Ohm, secondary - 8–12 kOhm.

Step-by-step instructions for replacing spark plugs on Almere G15

Replacing spark plugs with Nissan Almera G15 does not require special skills, but there are several critical nuancesthat are often overlooked: for example, the order of unscrewing (so as not to damage the threads in the head of the block) and the tightening torque of new spark plugs. Here are the detailed instructions:

Required tools:

• 🔧 16 mm spark plug wrench with rubber seal (so as not to damage the insulator).
• 🔧 Extension cord and ratchet (or wrench).
• 🔧 Torque wrench (optional, but recommended for precise tightening).
• 🧴 Silicone grease or WD-40 (for thread processing before unscrewing).
• 🧲 Magnet or tweezers (to get the candle out of the well).

Work order:

1. Disconnect the negative terminal of the battery (this is necessary to avoid short circuits when working with high-voltage wires).

2. Remove the decorative engine cover (it is secured with 4 plastic clips).

3. Disconnect the ignition coil connectors (press the lock and pull up). Be careful - the contacts are fragile!

4. Unscrew the coil mounting bolts (10 mm wrench) and carefully remove the coils. If they get stuck, don’t pull them—sway them from side to side.

5. Before unscrewing the spark plugs necessarily Blow out the spark plug wells with compressed air (or use a brush) to prevent dirt from getting into the cylinders.

6. Place the spark plug wrench on the spark plug and unscrew it counterclockwise. If the spark plug does not budge, do not apply excessive force - treat the thread WD-40 and wait 10 minutes.

7. Remove the old spark plug and inspect the threads in the cylinder head. If there are traces of corrosion, treat them with a special lubricant (for example, Liqui Moly MoS2).

8. Install a new spark plug into the well and screw it in by hand until it stops, then tighten it with a torque wrench 20–25 Nm. Without a torque wrench, tighten 1/2 turn past the stop.

9. Repeat the procedure for the remaining candles. Replacement order: 1–3–4–2 (this reduces the load on the cylinder head).

10. Reassemble everything in reverse order. After connecting the coils, check that the connectors are seated until they click.

⚠️ Attention: Never use a spark plug wrench as a lever - this may break the ceramic insulator. If the spark plug does not unscrew, it is better to contact a service center rather than risk damaging the threads in the cylinder head (its restoration will cost 15–20 thousand rubles).

After replacement, start the engine and check its operation at idle speed. If vibrations occur or the Check Engine, this means that one of the spark plugs is undertightened or overtightened, or the coils are damaged during installation.

Iridium vs platinum vs nickel: which spark plugs are better for Almera G15

On owner forums Almera G15 The debate continues about which spark plugs are better: original iridium, platinum analogues or budget nickel ones. Let's look at the pros and cons of each option:

Candle type	Pros	Cons	Recommendations
Iridium (NGK IFR6T11, Denso IXUH22I)	✅ Service life up to 100,000 km ✅ Stable sparking at low temperatures ✅ Less fuel consumption (3–5%) ✅ Thin central electrode (0.6 mm) for better ignition	❌ High price (RUB 1,200–1,800 per set) ❌ Sensitive to fuel quality ❌ Fakes are common	The optimal choice for most owners. They pay for themselves through fuel savings.
Platinum (NGK LZFR6AP-11, Denso PK20PR-P8)	✅ Resistant to high temperatures (good for HBO) ✅ Last longer on gas (up to 80,000 km) ✅ Less risk of electrode erosion	❌ More expensive than iridium ones (up to 2,500 rubles per set) ❌ Cold starts may be worse (compared to iridium)	Recommended for cars with LPG or for frequent trips at high speeds.
Nickel (Beru Z 322, Bosch FR7DPX)	✅ Low price (300–500 rubles per set) ✅ Easy to find in any store ✅ Less critical of fuel quality	❌ Service life - 30,000–50,000 km ❌ Larger gap over time (requires adjustment) ❌ Acceleration dynamics may worsen	Suitable for temporary replacement or on a limited budget.

Many Almera G15 owners are experimenting with multi-electrode spark plugs (For example, Bosch Super Plus), promising a more stable spark. However, in practice they do not provide noticeable advantages over the original iridium ones, and in some cases they even worsen starting due to a less concentrated spark.

If you decide to save money and install nickel candles, be prepared for the following:

• 🔧 They will have to be changed in 2–3 times more often (every 30–40 thousand km).
• 🛢️ Fuel consumption may increase by 0.3–0.5 l/100 km.
• ⚡ In frosts below -20°C, problems with starting are possible (especially if the battery is not new).

The myth about “eternal” iridium spark plugs

In fact, iridium spark plugs wear out too, just more slowly. The main reasons for their failure:

- Erosion of the central electrode (iridium “burns out” over time).

- Carbon deposits on the insulator due to low-quality fuel or oil.

- Mechanical damage due to careless installation.

Even original NGK IFR6T11 after 80–90 thousand km often have an increased gap and require replacement, despite the stated 100 thousand km.

Top 5 mistakes when replacing spark plugs on Almere G15

It would seem that replacing spark plugs is a simple procedure, but even experienced car owners make mistakes, which are then costly. Here are the most common:

1. Ignoring torque. An overtightened spark plug can damage the threads in the aluminum block head (repair - from 10 thousand rubles). Under-tightened will lead to misfires and vibrations. Optimal moment for Almera G15 - 20–25 Nm.

2. Using inappropriate candles. For example, installing candles with a heat rating 6 instead of 5 (like the original ones) will lead to detonation and overheating of the engine. Always check the labeling!

3. Dirt getting into the cylinders. If you do not blow out the spark plug wells before removing them, sand and dust will enter the combustion chamber and can damage the pistons or cylinder walls. Use a compressor or at least a brush.

4. Damage to the insulator during installation. If you drop a spark plug or hold it by the insulator with a key, microcracks may appear, which will then lead to a spark breaking through to the body.

5. Failure to check the gap on new spark plugs. Even original spark plugs in the factory packaging may have the wrong gap. Always check it round probe (flat probe gives inaccurate results).

Another common mistake is replacing spark plugs one at a time. If you unscrewed all four, then you need to replace them as a set, even if three spark plugs look normal. Different wear of the electrodes will lead to uneven operation of the cylinders and increased vibration.

How to check spark plugs without special equipment

If you do not have a diagnostic scanner or a multimeter, you can assess the condition of the spark plugs using improvised means. Here are some methods:

1. Visual inspection

Unscrew the spark plug and inspect it in good light:

• 🔍 Normal soot color: light gray or brown. Indicates proper engine operation.
• ⚫ Black velvety soot: rich fuel mixture (possibly clogged injectors or faulty air flow sensor).
• ⚪ White soot: lean mixture or overheating (check thermostat and spark plug rating).
• 🛢️ Oil soot (black and greasy): oil enters the combustion chamber (rings or caps are worn out).
• 🔥 Melted electrodes: detonation or improper heat rating.

2. Checking the spark

For this you will need arrester (you can make it yourself from two bolts welded to pliers). Algorithm:

1. Unscrew the spark plug and insert it into the spark gap.
2. Place the arrester body against ground (for example, a valve cover).
3. Have a helper turn the starter (without starting the engine).
4. There must be a spark stable, bright blue and jump between the electrodes without skipping. If the spark is weak (orange) or absent, the spark plug is faulty.

3. Test by ear

If it is not possible to unscrew the spark plugs, you can try to identify the faulty one by sound:

1. Start the engine and open the hood.
2. Disconnect the high-voltage wires from the coils one by one (or remove the coil connectors).
3. If the engine sound does not change when one of the cylinders is turned off, the problem is in this spark plug or coil.

⚠️ Attention: When checking the spark, do not hold the spark plug in your hand - the voltage on the electrodes reaches 20–30 kV, which is life-threatening! Use dielectric gloves or tools with insulated handles.

Frequently asked questions about spark plugs for Nissan Almera G15

Is it possible to use candles with a different heat rating?

No, this will lead to serious problems. Candles with lower heat number (For example, NGK BPR5ES instead of BPR6ES) will overheat, causing detonation and damage to the pistons. Candles with a large number (For example, BPR7ES) on the contrary, will quickly become overgrown with carbon deposits and lead to misfires. For Almera G15 only the heat rating is suitable 6.

What happens if you don’t change spark plugs for more than 100,000 km?

After 100 thousand km, iridium spark plugs lose their properties: the gap increases to 1.3–1.5 mm, which leads to:

• 🔥 Increased load on ignition coils (they fail 2-3 times more often).
• 🛢️ Increased fuel consumption by 10–15%.
• 🚗 Loss of power (the car accelerates worse, especially at high speeds).
• 💨 Damage to the catalyst due to incomplete combustion of fuel.

Worst case scenario could happen destruction of the insulator, and its fragments will fall into the cylinder, which will lead to scoring on the mirror and major repairs.

How to distinguish original NGK from a fake?

Fake candles NGK IFR6T11 often sold under original article numbers. Here are the signs of a fake:

• 📦 Packaging: The original has a hologram and barcode on the box, which can be checked on the NGK website.
• 🔍 Marking: on the original candles, the letters and numbers are clear, without blurred edges. Counterfeits often have crooked fonts.
• 🔧 carving: in the original it is perfectly smooth, without burrs. On fakes, traces of sloppy cutting are often visible.
• 💎 Central electrode: The original NGK is thin (0.6 mm) and has clear edges. For fakes, the electrode is thicker and may be uneven.
• 💰 Price: if the candle costs less than 1,000 rubles. per piece - this is 100% fake.

The most reliable way is to buy candles from official dealers or trusted sellers (for example, Exist.ru, Autodoc).

Do I need to lubricate the spark plug threads before installation?

Yes, but only special high temperature lubricant (For example, Liqui Moly MoS2 or NGK CB6). This prevents:

• 🔧 Sticking of the spark plug to the block head (especially relevant for aluminum cylinder head).
• 🔥 Corrosion of threads due to temperature changes.
• 💨 Moisture gets into the threaded connection.

Do not use for lubrication WD-40, Litol or graphite lubricant - they are not designed for high temperatures and can coke.

Is it possible to remove carbon from candles and reuse them?

Theoretically yes, but in practice it is inappropriate. Even after cleaning:

• 🔧 Gap between electrodes already increased due to erosion, and adjust it to the factory value (1.0–1.1 mm) is impossible.
• 💎 Iridium sputtering on the central electrode becomes thinner and the spark becomes less stable.
• 🛠️ Ceramic insulator may have microcracks that will lead to breakdown.

If the candles have served less than 50% of the declared resource, you can try cleaning them sandblaster or ultrasound, but this is a temporary measure. For Almera G15, the price of new original spark plugs (~1,500 rubles per set) is not commensurate with the risks.