Nissan Almera N16 with engines QG16DE And QG18DE - reliable cars, but their gas distribution mechanism requires periodic maintenance. Adjusting the valves on these engines is not a whim, but a necessity: incorrect clearances lead to loss of power, increased fuel consumption and even piston breakdowns when the timing belt breaks due to clamped valves. In this article, we will look at when and how to make adjustments, what tools are needed, and what mistakes car owners most often make.

Unlike modern engines with hydraulic compensators, Almera N16 equipped with mechanical lifters, where valve clearances increase over time due to wear. The manufacturer recommends checking them every 90–100 thousand km, but in practice the interval depends on the quality of the oil, driving style and operating conditions. If you hear a characteristic “clunking sound” from under the valve cover on a cold engine that does not go away after warming up, this is a sure sign that it’s time to grab the dipsticks and wrenches.

When valve adjustment is needed on Almera N16: signs and frequency

Official regulations Nissan instructs to check valve clearances Almera N16 every 90,000 km, but this interval is relevant for ideal conditions: high-quality oil, quiet driving, no overheating. In the realities of Russian roads and fuel, it is better to shorten the period to 60–70 thousand km. This is especially true for cars with an engine QG18DE, where thermal loads are higher due to the larger working volume.

The main symptoms that the valves require attention are:

  • 🔊 Knocking or knocking in the upper part of the engine, worsening when cold. The sound does not disappear after warming up or becomes quieter, but does not disappear completely.
  • 📉 Power reduction and “dullness” of the engine during acceleration, especially at low speeds.
  • ⛽ Increased fuel consumption (by 10–15%) for no apparent reason.
  • 🔥 Unstable idle or “triple” if the gaps are critically large and the valve does not close completely.

If you ignore these signs, the consequences can be serious: from burnt-out valves to pistons meeting plates when the timing belt breaks. For example, on QG16DE when the valves are clamped, the risk of bending if the belt breaks is 80%, while with the correct gaps - no more 20%.

⚠️ Attention: If after replacing the timing belt or camshafts you notice valve knocking, this is normal in the first 500–1000 km. The parts are ground in and the sound should disappear. If not, adjustment is required.

What valve clearances should be on Almera N16 (QG16DE and QG18DE)

Valve clearances at Almera N16 differ for intake and exhaust valves and also depend on engine temperature. The manufacturer specifies values for cold engine (temperature not higher than +20°C). If you adjust on a hot engine, the gaps will be too high, since the metal expands when heated.

Official clearance values for engines QG16DE And QG18DE:

Valve type Gap (mm) Tolerance (mm)
Intake 0.25–0.35 ±0.03
Graduation 0.30–0.40 ±0.03

Important: clearances are checked only on a cold engine. If the ambient temperature is below 0°C, a slight reduction in the gap is allowed (by 0.02–0.03 mm), since the metal is compressed. For accuracy use set of probes with a step of 0.01 mm - cheap probes with a step of 0.05 mm will give an error.

In practice, many craftsmen recommend setting the gaps closer to upper tolerance limit (for example, 0.33 mm for intake and 0.38 mm for exhaust). This is due to the fact that over time the clearances decrease due to wear on the camshaft cams and tappets. If you set them at the lower limit, a knock may appear after 20–30 thousand km.

📊 How often do you adjust the valves on your Almera N16?
  • Every 60 thousand km
  • Every 90 thousand km
  • Only when there's a knock
  • Never regulated
  • I don't know when was the last time this was done

Tools and materials for valve adjustment

For self-adjustment of valves on Almera N16 you will need a specialized tool. Do not try to make do with “improvised means” - this is fraught with errors and repeated disassembly. Here's the full list:

  • 🔧 Set of probes (necessarily in increments of 0.01 mm, for example, Jonnesway or Kingo).
  • 🔩 10 mm socket wrench to unscrew the valve cover.
  • 🔧 Open-end wrench 13 mm for adjusting bolts.
  • 🔧 14mm locknut (Sometimes there is a size of 13 mm - check before purchasing!).
  • 🛠️ Flat blade screwdriver for turning the camshafts.
  • 🧲 Magnetic holder or tweezers for removing washers (if replacement is required).
  • 🧴 Valve cover sealant (For example, Loctite 574 or ABRO 99-003).
  • 🧹 Carburetor Cleaner or kerosene for washing parts.

Also useful torque wrench for tightening the valve cover (torque - 8–10 Nm). If it is not there, tighten the bolts crosswise in 2-3 approaches, avoiding distortions. Do not use sealant over the entire area of ​​the lid - just a thin layer around the perimeter, otherwise excess may get into the oil.

⚠️ Attention: On some Almera N16 After 2004, there are adjusting bolts with left-hand threads on the exhaust valves. Before starting work, check the direction of the thread so as not to break it when tightening!

Cool the engine (temperature no higher than +20°C)|Disconnect the battery terminal|Remove the air filter and pipes|Clean the valve cover from dirt|Prepare tools and probes-->

Step-by-step instructions: how to adjust valves on Almera N16

Valve adjustment process Almera N16 requires accuracy and consistency. If you have never performed such work, it is better to practice on a removed cylinder head or invite an experienced technician. Below are detailed instructions taking into account the nuances QG16DE And QG18DE.

Step 1. Preparation and dismantling

1. Make sure the engine is cold (it has been standing for at least 4-5 hours).

2. Remove the negative terminal from the battery.

3. Remove the air filter, pipes and throttle cable (on the manual transmission).

4. Unscrew the 8 bolts of the valve cover (10 mm socket wrench) and remove it. Be careful - there may be oil residue under the lid.

Step 2. Installing the piston of the 1st cylinder at TDC

1. Remove the spark plug of the 1st cylinder (from the timing belt side).

2. Insert a screwdriver or a long feeler gauge into the spark plug hole - this will help determine TDC.

3. Turn the crankshaft clockwise (using the pulley bolt or the starter) until the mark on the camshaft pulley matches the mark on the rear cover and the piston of the 1st cylinder reaches top dead center (TDC).

Step 3: Checking and adjusting gaps

On Almera N16 the valves are adjusted in a strict order, since the camshaft cams at TDC point in different directions. Sequence for QG16DE/QG18DE:



1-й цилиндр: выпускной (6), впускной (3)


3-й цилиндр: выпускной (2), впускной (5)


4-й цилиндр: выпускной (8), впускной (1)


2-й цилиндр: выпускной (4), впускной (7)

To check the gap:

1. Insert a feeler gauge between the camshaft cam and the adjusting bolt.

2. The probe should enter from light effort - if it passes too freely or does not enter at all, adjustment is required.

3. Loosen the locknut with a 14 mm wrench and rotate the adjusting bolt (13 mm wrench) until the desired clearance is achieved.

4. Tighten the locknut, holding the bolt from turning, and recheck the clearance.

Step 4. Check and assembly

1. Rotate the crankshaft 2 turns and recheck the clearances of the 1st and 3rd cylinders.

2. Install the valve cover onto the new sealant and tighten the bolts crosswise.

3. Connect all pipes and battery terminal.

4. Start the engine and check for knocking noises and oil leaks.

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If after adjustment a knock appears on a hot engine, check the clearances again - perhaps you used the wrong feeler gauges or did not tighten the locknuts.

Common mistakes when adjusting valves and how to avoid them

Even experienced craftsmen sometimes make mistakes that lead to repeated disassembly or accelerated wear of parts. Here are the most common mistakes when working with Almera N16:

  • 🔥 Adjustment on a hot engine. Hot clearances will be too high, since the aluminum head expands more than steel pushers. Always cool the engine before operating.
  • 🔧 Using inaccurate styli. Cheap feeler gauges with 0.05 mm pitches do not allow you to set the gap with the required accuracy. An error of 0.02 mm is already critical for exhaust valves.
  • 🔩 Improper tightening of locknuts. If you tighten it, the adjusting bolt may turn; if you don’t tighten it enough, the gap will “go away” after 1000 km. Always use a torque wrench (torque 18–22 Nm).
  • 📏 Violation of the adjustment order. If you adjust the valves out of the TDC sequence, you will get incorrect clearances. For example, cylinders 2 and 4 are often confused.
  • 🧴 Saving on sealant. Cheap sealants tan and crumble, which leads to oil leaks. Use only specialized valve cover compounds.

Another common mistake is ignoring post-assembly checks. Always turn the crankshaft 2 turns and re-measure the clearances. If at least one valve has moved more than 0.02 mm, the adjustment must be repeated.

⚠️ Attention: On engines QG18DE after 2003, “floating” gaps are sometimes encountered due to wear on the seats of the adjusting bolts. If after adjustment the gap changes during inspection, the pushers need to be replaced.
What happens if the valves are adjusted incorrectly?

If the gaps overpriced, the valves will not open completely, which leads to a loss of power (up to 15–20%), increased fuel consumption and overheating of the exhaust valves (risk of burnout). If the gaps underestimated, the valves do not close tightly, which causes loss of compression, “tribbing” and the risk of meeting the pistons if the timing belt breaks. On QG16DE this almost guaranteed leads to bent valves and major repairs.

Cost of valve adjustment: do it yourself or go to a service center?

Valve adjustment price Almera N16 in services varies from 3,000 to 6,000 rubles, depending on the region and service station level. At official dealerships Nissan the cost can reach 8,000–10,000 rubles, but they guarantee accuracy and use original consumables. Self-adjustment will cost 500–1,500 rubles (cost of probes, sealant and cleaner), but it will require time and accuracy.

When to go to the service:

  • 🔧 If you do not have experience working with timing belts or special tools (torque wrench, precision feeler gauges).
  • ⏳ If it is important for you to save time, adjustment in the service takes 1.5–2 hours, but you will spend 4–6 hours on your own.
  • 🔍 If after self-adjustment there is still a knock or the engine is unstable.

When you can do it yourself:

  • 💰 If the budget is limited, but your hands “grow from the right place.”
  • 📚 If you are ready to study the process and follow the instructions.
  • 🔧 If you have an assistant to scroll the crankshaft or fix the camshafts.

Average cost of work and spare parts for service:

Service/Material Price (RUB)
Valve adjustment (operation) 3 000–6 000
Valve cover sealant 300–800
Valve cover gasket (if replaced) 500–1 200
Test leads (set) 500–1 500
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If you decide to adjust the valves yourself, be sure to take a photo or mark with a marker the position of the camshafts and TDC marks before disassembling. This will help avoid assembly errors.

Frequently asked questions about adjusting Almera N16 valves

Is it possible to adjust valves on a hot engine?

No, this is a grave mistake. Gaps on Almera N16 indicated for a cold engine (up to +20°C). On a hot engine, the aluminum head expands more than steel pushers, so the clearances will be too high. Adjusting “hot” will lead to valve knocking after cooling.

How often do you need to adjust the valves if you drive on gas?

When operating on HBO The thermal load on the exhaust valves is higher, so adjustments should be carried out more often - every 50–60 thousand km. It is also recommended to check the gaps at every maintenance (every 15 thousand km), since gas burns slower than gasoline, which increases the temperature in the combustion chamber.

What should I do if there is still a knocking sound after adjustment?

There may be several reasons:

  • Inaccurate feeler gauges - repeat adjustment with a quality tool.
  • Incorrect tightening of locknuts - check the torque (18–22 Nm).
  • Worn camshaft cams or tappets require replacement.
  • If oil or dirt gets under the adjusting bolt, clean the parts.

If the knocking noise does not go away, contact a service center for diagnostics.

Is it possible to drive with knocking valves?

For a short time (up to 1,000–2,000 km) it is possible, but this will accelerate the wear of the camshafts and pushers. Long driving with a knock leads to:

  • Reduced power and increased fuel consumption.
  • Burnout of exhaust valves (due to overheating).
  • Risk of valve bending if the timing belt breaks.

Don't put off adjustment for too long!

Do I need to change the oil after adjusting the valves?

If you removed the valve cover and dirt could get into the engine, yes. It is also recommended to change the oil if it has already used up more than half of its service life. Use oil with viscosity 5W-30 or 5W-40 (For example, Liqui Moly Special Tec AA or Mobil 1 ESP Formula).