Spark plugs for Nissan Almera G15 (K4M): how to select and replace without errors

Nissan Almera G15 with engine K4M (1.6 l, 16 valves) is one of the most popular cars in Russia due to its reliability and ease of maintenance. However, even such a proven engine has weak points, and spark plugs are one of them. Wrong choice or untimely replacement can lead to misfires, increased fuel consumption and even damage to ignition coils due to increased clearance.

In this article we will look at which candles are suitable for Almera G15 K4M according to factory specifications, how to distinguish the original from a fake, when to change them, and why cheap analogues can result in expensive repairs. And also - step-by-step instructions for replacement with photos and videos, typical mistakes of beginners and answers to frequently asked questions.

Original spark plugs for Almera G15 K4M: articles and characteristics

The manufacturer recommends for Nissan Almera G15 with engine K4M candles with article number 22401-JM01A (manufacturer - NGK). This iridium spark plugs with heat number 6, gap 0.9–1.1 mm and carving M14×1.25. Important: original candles are supplied in original packaging Nissan, but are produced NGK by special order.

Alternative original article - 22401-4M015 (also NGK, but for Asian markets). Both options are interchangeable, but the first is more common in Russian dealerships. Service life of original spark plugs: up to 100,000 km, but in practice it is recommended to change them every 60–80 thousand km due to low quality fuel.

• 🔧 Original article: 22401-JM01A (EUR) / 22401-4M015 (ASIA)
• 🔥 Type: iridium, with a thin central electrode
• ⚡ Clearance: 0.9–1.1 mm (no adjustment required)
• 📏 Thread: M14×1.25, length 26.5 mm
• 💰 Cost (2026): ~1,200–1,500 RUR per piece from official dealers

⚠️ Attention: There are often fakes on the market under the article number 22401-JM01A with the inscription "Made in Japan" on the packaging. The original has a holographic sticker Nissan and a serial number on the spark plug, which can be checked through the service Nissan Genuine Parts.

Analogs of original candles: what to choose instead of NGK

Original candles NGK for Almera G15 are expensive, so many owners choose analogues. Main rule: heat number should be 6, and the material of the central electrode is iridium or platinum. Nickel candles (even with the correct heat rating) will last 2–3 times less.

The best analogues in terms of price/quality ratio:

Brand	Article	Type	Gap (mm)	Service life (thousand km)	Note price (₽)
NGK	IFR6A11	Iridium	0.9–1.1	80–100	800–1 000
Denso	IK16	Iridium	0.9–1.1	80–100	700–900
Bosch	0 242 236 566	Iridium	0.9–1.1	60–80	600–800
Beru	Z 322	Nickel (budget)	0.9–1.1	30–40	200–300

Candles Denso IK16 - the most popular analogue among owners Almera G15. They are 30–40% cheaper than the original, but are not inferior in characteristics. Bosch 0 242 236 566 are also good, but some users complain about rapid wear of the side electrode. Beru Z 322 - a budget option for those who are ready to change spark plugs every 30–40 thousand km.

When to change spark plugs: signs of wear and recommendations

The manufacturer recommends replacing spark plugs every 100,000 km, but in Russian realities this interval should be reduced to 60–80 thousand km. Reasons:

• 🛢️ Low quality fuel (additives, sulfur, water)
• 🚗 Frequent driving over short distances (plugs do not warm up to operating temperature)
• 🌡️ Engine overheating due to traffic jams or faulty cooling system

Signs that it’s time to change the spark plugs:

• ⚡ Misfires (the engine “troits”, especially when cold)
• 🔥 Increased fuel consumption (10–15% higher than usual)
• 🚗 Power drop (stupid acceleration, failures when accelerating)
• 💨 Black or white soot on electrodes (checked visually)
• 🔊 Popping sounds in the exhaust system (unburnt air-fuel mixture)

⚠️ Attention: If detected on candles oil deposits (black greasy film), the problem is not in them, but in worn valve stem seals or piston rings. Replacing spark plugs will not help here - the engine needs to be repaired.

What happens if you don't change spark plugs on time?

Driving for a long time on worn spark plugs leads to:

- Damage to ignition coils (due to increased clearance and breakdowns).

- Detonation in the cylinders, which destroys the pistons and valves.

- Catalyst clogging unburned fuel (repairs will cost 30–50 thousand rubles).

- Increased load on the starter (especially in winter).

Step-by-step replacement of spark plugs on Almera G15 K4M: instructions with nuances

Replacing spark plugs with Nissan Almera G15 with engine K4M does not require special skills, but there are several critical nuancesthat are often missed:

1. Disconnect the battery (remove the negative terminal) to avoid short circuit when working with the coils.
2. Use 10 mm socket wrench with extension cord and spark plug head 16 mm with a magnet (candles deep in wells).
3. Before unscrewing the spark plugs blow out the wells with compressed air (dust and debris should not get into the cylinders!).
4. New candles tighten by hand until it stops, then tighten with a torque wrench 20–25 Nm.

Step by step process:

16mm spark plug wrench with magnet|10mm socket wrench and extension|Torque wrench (optional)|Compressor or can of compressed air|Dielectric grease (for coils)|New spark plugs (4 pcs.)-->

1. Remove the decorative engine cover (snap off the 4 plastic clips).

2. Disconnect the ignition coil connectors (press the lock and pull up).

3. Unscrew the coil mounting bolts (torx T30 or key to 10 mm).

4. Remove the coils (pull gently up, do not pull the wires!).

5. Unscrew the old spark plugs counterclockwise. If the candle is stuck, do not use force - treat the well WD-40 and wait 10 minutes.

6. Install new spark plugs, having first checked the gap with a feeler gauge (should be 0.9–1.1 mm).

7. Reassemble everything in reverse order, making sure that the coil connectors are seated until they click.

Typical mistakes when replacing spark plugs and their consequences

Even experienced car owners sometimes make mistakes that lead to serious problems. Here are the most common:

• 🔧 Re-upholstery of candles - leads to damage to the threads in the cylinder head (repair will cost 15–20 thousand ₽).
• 🧲 Using spark plugs with the wrong gap - too large a gap causes misfires, too small - a weak spark.
• 🔥 Debris getting into the cylinders — even fine dust can become an abrasive and damage the cylinder mirror.
• ⚡ Connecting the coils in the wrong order - the engine will rev and the dashboard will light up Check Engine.
• 🛑 Ignoring the error code after replacement - if Check Engine does not go out, you need to reset the error with the scanner (for example, ELM327).

⚠️ Attention: If after replacing the spark plugs the engine begins to run worse (vibrations, misfires), check:

- Correct connection of the coils (order: 1–3–4–2, when viewed from the radiator).

- The gap on new spark plugs (even with the original it can “leave” during transportation).

- Condition of high-voltage wires (cracks or insulation breakdowns).

How to check spark plugs without removing them: diagnosis based on symptoms

It is not always possible to unscrew the spark plugs for inspection. In such cases, they are diagnosed by indirect signs:

• 🔍 Vibration at idle - a sign of misfire in one or more cylinders.
• 📉 Drop in speed when turning on the air conditioner — spark plugs do not produce sufficient spark under load.
• 🚦 Jerks during acceleration (especially at speeds of 60–90 km/h) - the air-fuel mixture burns unevenly.
• 🔥 Smell of gasoline from the exhaust pipe — the fuel does not burn out due to a weak spark.

For an accurate diagnosis, use OBD-II scanner (For example, ScanTool Pro or Launch CReader). Error codes related to candles:

• P0300 — random misfires;
• P0301–P0304 — misfires in a specific cylinder (1–4, respectively);
• P0351–P0354 - ignition coil malfunction.

If the scanner shows errors P030X, change the spark plugs first. If the error remains, check the coils, wires and compression in the cylinders.

FAQ: Frequently asked questions about spark plugs for Almera G15 K4M

Is it possible to use platinum spark plugs instead of iridium spark plugs?

Yes, but only if the heat rating and gap meet the requirements (6 and 0.9–1.1 mm, respectively). Platinum candles (eg NGK PFR6A11) are slightly cheaper than iridium ones, but last 10–15% less. The main thing is not to use nickel candles, even if they are the right size.

What happens if you install spark plugs with a gap of 1.3 mm?

Increased clearance leads to:

• Misfires (especially at high speeds);
• Increased load on the ignition coils (they can burn out);
• Impaired engine starting in cold weather.

If you have already purchased spark plugs with the wrong gap, you can adjust it with a special tool (but not a hammer!).

How often should candles be cleaned?

Cleaning spark plugs (sandblasting or ultrasonic) is a temporary measure. It can extend their life by 10–15 thousand km, but will not return their original characteristics. If the spark plugs have worked for more than 50 thousand km, it is better to replace them. Cleaning is only justified for iridium/platinum spark plugs with low mileage (for example, if carbon deposits appeared due to poor fuel).

Why do new spark plugs quickly become covered with soot?

Reasons:

• Malfunction lambda probe (over-enriched mixture);
• Wear valve stem seals (oil enters the combustion chamber);
• Low quality fuel (additives do not burn completely);
• Incorrect driving style (frequent short trips without warming up).

If carbon deposits appear after 5–10 thousand km, diagnose the engine.

Is it possible to drive with one broken spark plug?

Technically possible, but highly undesirable. Long-term driving with misfires leads to:

• Overloading the catalyst (it may melt);
• Increased wear of the piston group;
• Increased fuel consumption by 20–30%.

If the spark plug “died” on the road, drive to the service station at minimum speed (not higher than 3,000 rpm).