Owning a car requires regular maintenance, and one of the most critical operations is servicing the gas distribution system. For owners Nissan Almera G15 with the H4M (HR16DE) engine, this procedure becomes inevitable when a certain mileage or age of the belt is reached. Ignoring replacement dates can lead to catastrophic consequences for piston group, since the design of the motor does not provide protection against valves meeting pistons in the event of a break.
Many car owners are afraid to take on this work themselves, fearing difficulties with tensioning or installing marks. However, if you have a minimum set of tools and strictly follow the sequence of actions, replacing the timing belt with Nissan Almera G15 quite doable in a garage. The main task is to maintain synchronization of the crankshaft and camshafts so that the engine starts and runs stably.
Preparing tools and work area
Before starting work, you need to organize a comfortable space. Under Nissan Almera G15 a pit or lift will be required as access to the underside of the engine is limited. A standard set of wrenches is often not enough, so prepare in advance a specific tool for turning the crankshaft and fixing the camshafts.
You will need:
- 🔧 Set of sockets and ratchets (sizes from 8 to 19 mm)
- 🔑 Ratchet wrench with extension for access to the crankshaft pulley
- 📏 Special tool for fixing camshafts (bar)
- 🔦 Powerful flashlight for illuminating the internal cavities of the engine
Don't forget about the new kit timing belt. It is advisable to purchase an original belt from Nissan or proven analogues, such as Gates or Contitech. It is also worth replacing the tension roller and water pump, since their service life often coincides with the service life of the belt.
It is important to understand that saving on the quality of components can result in multiple engine repair costs in the future.
Removing attachments and protective covers
The first stage of work is to remove all interfering elements. Start by disconnecting the battery to eliminate the risk of a short circuit if you accidentally touch the wiring. Remove the plastic decorative engine cover by unclicking the clips and unscrewing the mounting bolts.
Next, you need to dismantle the right wheel and fender liner to gain access to the lower mudguard. After this, remove the belt of auxiliary units (generator, air conditioner). This is done by loosening the tension roller, which has a special hole for fixing in the non-working position.
- ⚙️ Loosen the tension roller of the auxiliary belt
- 🛑 Remove the belt from the pulleys
- 🔩 Unscrew the fastenings of the fender liner and remove it
- 🚫 Remove the plastic engine protection from below
Pay special attention to removing the upper plastic timing belt cover. It is secured with several bolts and may have fragile latches that can be easily damaged if handled carelessly. Carefully disconnect the crankshaft position sensor if it interferes with the removal of the cover.
- Less than 60,000 km
- 60,000 - 100,000 km
- More than 100,000 km
- I don't know the mileage
Fixing the marks and removing the old belt
This is the most critical stage on which the correct operation of the engine depends. You need to set the crankshaft to the top dead center (TDC) of the first cylinder. To do this, rotate the crankshaft pulley clockwise until the mark on the pulley aligns with the mark on the oil pump housing.
The camshafts must also be aligned. On the rear timing cover there are special grooves at the ends of the camshafts. They must be positioned strictly horizontally. If they do not match, rotate the shafts to the desired position, but only in the direction of closing the valves to avoid the pistons hitting the valves.
To simplify the process, there are special clamps that are inserted into the grooves of the camshafts, locking them in the correct position. If you use such a tool, make sure it fits snugly against the engine housing.
☑️ Checking the position of the shafts
After fixing all the shafts, loosen the tension pulley bolt and remove the old belt. You need to remove it carefully so as not to knock off the marks on the gears. If the marks have moved, repeat the procedure for setting TDC again.
⚠️ Attention: Never turn the crankshaft or camshafts after removing the belt! This is guaranteed to disrupt the valve timing and require a complete re-tuning.
Replacing rollers and water pump
After removing the old belt, it is recommended to replace the tension pulley and idler pulley. Their bearings wear out over time, which can cause the new belt to become misaligned and wear out quickly. When replacing rollers, be sure to use new mounting bolts, as old ones may be deformed or have broken thread geometry.
Water pump (coolant pump) on Nissan Almera G15 driven by the timing belt. Its replacement is strongly recommended every time the belt is replaced. If the pump leaks after 20-30 thousand kilometers, you will have to disassemble half of the engine again, which will significantly increase the cost of repairs.
- 🔩 Unscrew the bolts securing the old pump
- 🧽 Clean the seat from old sealant
- 💧 Install a new pump with a new gasket
- 🛠Tighten the bolts to the recommended torque
When installing a new pump, pay attention to the presence of sealant. Usually a small layer is enough to avoid coolant leaks. Do not apply too much sealant, as excess sealant may get into the cooling system and clog the radiator.
What to do if the old pump has become stuck?
If the pump does not unscrew, do not use excessive force. Use a penetrating lubricant (WD-40) and give it time to work. You can carefully pry off the housing with a screwdriver, but be careful not to damage the engine block.
Installing a new belt and tensioning
Timing belt tension is a critical parameter. Too little tension will cause the marks to slip and break, and too much tension will cause rapid wear of the roller bearings and tension. On Nissan Almera G15 An automatic tensioner is used, which requires proper installation.
Install the new belt starting at the crankshaft pulley, then tension it over the intake camshaft pulley, idler pulley, exhaust camshaft pulley, and finally onto the tensioner pulley. Make sure the belt teeth engage tightly with the pulleys.
For correct tension, the tension roller must be rotated to a certain position. There is a mark on the roller body that should match the mark on the bracket. After aligning the marks, tighten the roller mounting bolt.
Before final tightening the tension roller bolt, turn the crankshaft two turns clockwise and check the alignment of the marks again. If the marks are lost, the procedure must be repeated again.
Control check and assembly
After installing the new belt and rollers, you must ensure correct assembly. Rotate the crankshaft two full turns (720 degrees) by hand. The marks on the crankshaft and camshafts must line up perfectly. If this happens, it means that the valve timing is set correctly.
Now you can reassemble the engine in reverse order. Install the upper timing cover, fender liner, right wheel and accessory belt. Connect the battery.
| element | Recommended tightening torque | Features |
|---|---|---|
| Crankshaft bolt | 105-115 Nm + additional turn | Needs replacement |
| Tensioner pulley bolt | 20-25 Nm | Tighten after installing the belt |
| Camshaft pulley bolt | 100-110 Nm | Fix the shaft with a key |
| Pump bolts | 10-12 Nm | Evenly around the circle |
| Alternator pulley bolt | 50-60 Nm | Check status |
Refill with coolant if it was drained when replacing the pump. Start the engine and let it idle. Listen to extraneous sounds. If the tension is correct, the belt should operate quietly.
⚠️ Attention: If you hear a metallic knocking or grinding noise after starting, turn off the engine immediately. This is a sign of incorrect belt installation or faulty rollers.
Correct timing belt tension guarantees long engine life and no starting problems. Neglecting this step can lead to belt breakage after just a few thousand kilometers.
Frequent mistakes and advice from professionals
One of the most common mistakes is incorrect installation of marks on the camshafts. On Nissan Almera G15 they must be strictly horizontal, but some craftsmen allow an error of one tooth, which leads to unstable engine operation and loss of power.
Another mistake is using an old crankshaft bolt. This bolt is a one-time use and can stretch when used repeatedly, causing the pulley to loosen and break off while driving.
- 🚫 Don’t skimp on the quality of the belt and rollers
- 🔍 Always check the condition of the camshaft seals
- 🛡 Use only original gaskets
- 📏 Check the tightening torque with a torque wrench
If you doubt your abilities, it is better to entrust this work to professionals. However, if you decide to do it yourself, follow the instructions carefully and take your time.
How to distinguish an original belt from a fake?
The original belt has clear markings and straight teeth. Counterfeits often have a smoother surface and less clear writing. The packaging of the original belt must be of high quality, with a hologram.
Results and conclusion
Replacing the timing belt with Nissan Almera G15 - this is a difficult but doable task for an experienced car enthusiast. The main thing is patience, attentiveness and compliance with all technical requirements. Do not neglect replacing the pump and rollers, as their service life often coincides with the belt service life.
Regular maintenance of the gas distribution system prolongs the life of the engine and ensures its reliable operation. Replace on time, and your car will serve you faithfully for many years.
⚠️ Attention: A timing belt failure on an H4M (HR16DE) engine is guaranteed to result in bent valves and costly cylinder head repairs. This is the most important reason not to delay replacement.
Frequently asked questions (FAQ)
What mileage is allowed before replacing the timing belt?
The recommended replacement interval is 60,000 km or 4 years of operation, whichever comes first. When driving in difficult conditions (dust, heat, traffic jams), it is better to reduce the interval to 40,000 km.
Is it possible to replace just the belt, without the rollers?
Theoretically it is possible, but it is highly not recommended. Old rollers have worn bearings that can seize or become noisy, causing the new belt to break. Replacing the kit is cheaper than rebuilding the engine.
Do I need to change the belt if the car has not been driven for a long time?
Yes. Over time, rubber hardens and loses its properties, even if the car has not been used. The age of the belt plays no less a role than the mileage.
How to check if the belt is installed correctly?
Rotate the crankshaft two turns by hand and check that all marks match. You can also start the engine and check the phases with an OBD2 scanner if in doubt.
What happens if you mix up the marks on one tooth?
The engine will run unstably, with loss of power and increased fuel consumption. In the worst case, the pistons can hit the valves at certain speeds.