Valve adjustment on Nissan Qashqai: Full technical review

Many crossover owners Nissan Qashqai encounter a characteristic metallic clatter under the hood, which is often confused with the operation of hydraulic compensators. However, the power units of the HR and MR series installed on this model use flat pushers that require periodic monitoring and valve clearance adjustment. Ignoring this requirement can lead to loss of power, increased fuel consumption and, in the worst case, burnt valves.

Procedure for adjusting clearances in Nissan Qashqai has its own technical features that differ from the usual procedures for cars with hydraulic compensators. You will need not only a set of specialized tools, but also a deep understanding of the design features of the engine so as not to damage fragile parts during disassembly.

Signs that your Nissan Qashqai an unscheduled check of the gaps is necessary; they manifest themselves in a change in the sound of the engine. If at idle you hear a distinct knocking sound reminiscent of a diesel engine, this is the first signal of a violation valve thermal clearance. You should also pay attention to unstable idle speed and difficulty starting a cold engine.

There is a misconception that modern Japanese car engines do not require maintenance of the valve mechanism throughout its entire service life. For Nissan Qashqai with engines HR16DE and MR20DE this statement is incorrect. The manufacturer recommends diagnostics every 40-60 thousand kilometers, and full adjustment when deviations are detected.

Design features of the engine and types of valve mechanism

Engines installed on Nissan Qashqai, are reliable atmospheric units, but their design dictates stringent maintenance requirements. Unlike engines with hydraulic compensators, which automatically adjust the gap to the temperature conditions, a system is used here flat pushers. This means that the clearance between the camshaft cam and the tappet must be set manually with high precision.

Valve drive mechanism Qashqai It has a timing chain drive, which simplifies maintenance since the chain lasts longer than the belt. However, the adjustment system itself requires removing the cylinder head or at least the camshafts to access the pushers. An incorrectly set gap entails a violation of the valve timing, which critically affects compression ratio in cylinders.

It is important to understand that there are two main types of tappets in these engines: adjustable and non-adjustable. In most cases on Nissan Qashqai pushers are used, into which adjusting washers are pressed. To change the gap, it is necessary to replace the washer with another one of a different thickness, which makes the process labor-intensive, but reliable.

⚠️ Attention: Never try to adjust clearances on a hot engine. Metal expands when heated, and you will get incorrect data, which will lead to misalignment of the valves after cooling.

For accurate diagnosis, you will need specialized probes. A regular set may not be suitable due to the narrow working gap. It is recommended to use a professional instrument that provides measurement accuracy down to hundredths of a millimeter. Error in 0.05 mm may cause knocking or, conversely, a loose valve fit.

Tools and preparation for the adjustment procedure

Before starting work, you must carefully prepare the workplace and collect all the necessary tools. Adjusting the valves Nissan Qashqai - This is a process that requires accuracy and the presence of specific equipment. You will need a set of sockets, a torque wrench, and measuring instruments to determine the thickness of the washers.

The most important tool is a micrometer or precision caliper. Without the ability to accurately measure the thickness of the old washer, you will not be able to select a new one. A set of adjusting washers is also needed, since during the work it often turns out that the required size is not available. Set of washers should cover the size range from 2.00 mm to 3.00 mm in 0.05 mm increments.

• 🔧 Set of sockets and ratchets (including 10, 12, 14 mm socket)
• 📏 Micrometer with measurement accuracy up to 0.01 mm
• ⚙️ Set of feeler gauges for measuring gaps (from 0.10 to 0.50 mm)
• 🔩 Torque wrench for tightening cylinder head bolts

It is equally important to ensure cleanliness in the work area. Even fine dust getting inside the timing mechanism can lead to rapid wear of the camshafts and pushers. Before removing the valve cover, thoroughly clean it and surrounding surfaces from dirt and oil. Use lint-free wipes and special cleaners.

It is also worth reading the technical documentation in advance. For each engine Nissan Qashqai There are factory clearance standards, which may differ for intake and exhaust valves. Ignoring this information will result in incorrect configuration. Be sure to compare your results with the table in the repair manual.

Step-by-step instructions for removal and diagnostics

The process begins with the removal of attachments that interfere with access to the valve mechanism. You need to remove the air filter housing, disconnect the sensor connectors and remove the ignition coils. On engines MR20DE You will also need to remove the intake manifold to gain free access to the rear of the cylinder head.

Remove the valve cover by unscrewing the bolts in the correct sequence to avoid deformation. Pay attention to the condition of the valve cover gasket. If it has hardened or shows signs of damage, it must be replaced. An old gasket will not provide a tight seal, which will lead to oil leaks and a burning smell in the cabin.

To measure the clearances, it is necessary to set the first piston to the top dead center (TDC) of the compression stroke. This can be done by rotating the crankshaft using a special wrench using the pulley bolt. Align the mark on the camshaft gear with the mark on the bearing housing. Only in this position can measurements be taken for the relevant valves.

• 🔍 Insert the feeler gauge between the camshaft cam and the pusher
• 📏 Assess the tightness of the probe (it should move with little effort)
• ✍️ Record all obtained values ​​in a table for later analysis
• 🔄 Check the clearances for all cylinders by cranking the engine half a turn

If the gaps are outside the permissible limits, it is necessary to begin adjusting them. This will require removing the camshafts to gain access to the lifters. This is the most critical stage, since incorrect installation of camshafts can lead to damage and disruption of valve timing.

How to properly remove camshafts?|To remove camshafts, you first need to loosen the bed bolts in a certain sequence so as not to deform the shafts. Then carefully remove the shafts, taking care not to damage the supporting surfaces. Don't forget to install them back strictly according to the marks.-->

After removing the pushers, they must be marked and numbered so as not to be mixed up. Each tappet is paired with a specific valve, and swapping them around can result in accelerated wear. Use a marker to mark the ends of the pushrods.

Installation and final assembly of the valve mechanism

After selecting new washers, proceed to install them. Carefully insert the washer into the pusher, making sure it sits evenly and does not protrude beyond the edges. In some cases, light pressure is required to get the washer into place. Make sure that the markings on the washer are facing up for ease of later inspection.

Install the pushers back into their seats, strictly following the numbering you made earlier. Never swap pushers, as this will disrupt the operation of the mechanism. Then carefully install the camshafts, following the marks on the gears. This is a critical step that requires maximum precision.

The camshaft bed bolts are tightened in several stages using a torque wrench. First tighten the bolts from the center outwards to a torque 10 Nm, then check the tightening torque. Improper tightening can cause the camshaft to become misaligned and cause rapid wear. Follow the tightening sequence specified in the manual.

• 🔩 Clean the bolt threads from oil and dirt
• 📐 Use a torque wrench for precise tightening
• 🔄 Check the tightening torque in several approaches
• 🔧 Make sure the timing marks are installed correctly

After installing the camshafts, you need to check the clearances again. Although in theory they should be correct, in practice it is always worth double-checking the result. Insert the feeler gauge and make sure the clearances are within specifications. If something is wrong, you will have to repeat the washers selection procedure.