Cylinder head gasket (cylinder head) in Nissan Sunny FB15 - a critical element responsible for the tightness of combustion chambers, oil and cooling channels. Its wear or breakdown leads to antifreeze getting into the oil and overheating the engine. GA15DE and even scuff marks on the cylinder mirrors. In this article we will look at how to diagnose a malfunction, what tools will be needed for replacement, and step by step We'll go through the entire process - from dismantling the valve cover to installing a new gasket and running in the engine.

Feature FB15 (1995–2000) - compactness of the engine compartment and a specific cylinder head mounting design: the bolts are tightened in 4 stages with a clear point. Errors here lead to deformation of the head or repeated burnout of the gasket. We took into account all the nuances, including unique tightening torque for cylinder head bolts for GA15DE - 65–70 Nm in the “inside-out” sequence, and collected checklists to control each stage.

Signs of a broken cylinder head gasket on a Nissan Sunny FB15

Symptoms of a bad gasket are often disguised as other engine problems. However there is 5 key signals, which directly indicate its breakdown:

  • 🔥 Engine overheating for no apparent reason (the fan is running, the thermostat is working). The antifreeze leaves, but there are no leaks under the car - which means it gets into the combustion chambers or oil.
  • 🛢️ "Mayonnaise" under the oil filler cap. A white or coffee-colored emulsion is a sure sign of mixing oil with coolant.
  • 💨 White smoke from the exhaust (even after warming up). Steaming exhaust with a sweetish smell - antifreeze is burning in the cylinders.
  • ⚡ Unstable operation at idle. Coolant entering the cylinders disrupts compression and the engine “troubles.”
  • 🔧 Traces of antifreeze on spark plugs. When dismantling the spark plugs, a white coating or drops of liquid are visible.

If you notice at least 2-3 signs from the list, the car cannot be driven - this leads to scuffing of the piston group and major repairs. For an accurate diagnosis, check:

  • 🔍 Compression in the cylinders (a drop of more than 20% from the norm - 12-13 bar).
  • 🧪 Color and consistency of oil (emulsion or foam).
  • 📉 Antifreeze level (sharp drop without external leaks).
📊 What symptom of a broken cylinder head gasket have you observed?
  • Engine overheating
  • White smoke from the exhaust
  • Emulsion in oil
  • Unstable speed
  • Other

Tools and materials for replacement

To work you will need specialized tool, since standard wrenches are not suitable for cylinder head bolts and pulleys. Here's the full list:

Category Name Note
Tool Torque wrench With a range of 20–100 Nm (for cylinder head bolts)
Tool Sockets 10, 12, 14 mm Extended 10 mm socket for rear cylinder head bolts
Tool Hexagon 5 mm To unscrew the valve cover
Materials Cylinder head gasket Nissan (article 11044-4M000) Original or Ajusa/Elring — avoid cheap analogues!
Materials Sealant Loctite 574 or Permatex Ultra Grey Only for oil channels (do not apply to the surface of the block!)

Additionally prepare:

  • 🧴 Coolant (5 l, Nissan L248 or equivalent).
  • 🛢️ Motor oil (4 l, viscosity 5W-30 or 10W-40).
  • 🔧 New cylinder head bolts (article 11026-4M000) — necessarily, since the old ones are stretched when tightened!
  • 🧯 Rags and solvent for cleaning the surfaces of the block and head.
⚠️ Attention: Never use old cylinder head bolts! They are designed for one puff and when used repeatedly, they do not provide the required force, which leads to gasket breakdown.

Preparation for replacement: draining liquids and dismantling the attachment

Before starting work cool the engine completely (block temperature should not exceed 30°C). Next:

  1. Drain the antifreeze. Unscrew the cap on the radiator (lower right corner) and engine block (14 mm wrench). Place a container with a volume of at least 6 liters.
  2. Remove the air filter. Disconnect the pipe from the throttle valve and unscrew the 4 bolts securing the filter housing (10 mm socket).
  3. Remove the valve cover. Unscrew the 8 bolts with a 5 mm hexagon, remove the cover and remove the gasket (it is disposable!).
  4. Set the piston of the 1st cylinder to TDC. Turn the crankshaft with a 22 mm wrench clockwise, aligning the mark on the pulley with the mark on the front cover.

Now you need to disconnect all pipes and connectors, interfering with the removal of the cylinder head:

  • 🔌 Disconnect the coolant temperature sensor connector (located on the thermostat).
  • 🚿 Remove the throttle body and intake manifold heating pipes.
  • ⚡ Disconnect the high-voltage wires from the spark plugs.
  • 🔗 Release the accelerator cable (unscrew the 10 mm nut on the throttle bracket).

Drain the antifreeze and oil|Disconnect the battery (negative terminal)|Remove the air filter and pipes|Set TDC of the 1st cylinder|Disconnect all connectors and cables-->

After dismantling the attachment take photographs of the location of pipes and connectors - this will simplify reassembly. Pay special attention to:

  • 📸 Position of timing marks (on the camshaft and crankshaft pulleys).
  • 📸 Marking of high-voltage wires (so as not to be confused during installation).

Removing the cylinder head: step-by-step instructions

This is the most critical stage. Incorrect order of unscrewing the bolts or a violation of the sequence leads to deformation of the head! Proceed strictly according to the algorithm:

  1. Unscrew the camshaft mounting bolts. Use a 12mm socket, starting with the outermost bolts and working towards the center. The order is important to avoid bending the shaft.
  2. Remove the camshafts. Carefully remove them together with the seals (do not lose the keys!). Place on a clean surface, avoiding scratches on the necks.
  3. Unscrew the cylinder head bolts. Use a torque wrench and be sure to keep order (see diagram below). Start by loosening all bolts 1-2 turns, then unscrew completely.

[Here should be a diagram of the order of unscrewing the cylinder head bolts for GA15DE]

After removing the bolts:

  • 🔧 Remove the block head. If it gets stuck, carefully pry it off with a screwdriver at the joint with the block (do not use a pry bar!).
  • 🧹 Clean the block and head surfaces from the remains of the old gasket. Use a plastic scraper and solvent (eg WD-40). Prohibited use sandpaper - it ruins the flatness!
  • 🔍 Check the head for deformation. Apply a metal ruler to the plane and measure the gap with a feeler gauge. The permissible value is no more than 0.05 mm.
⚠️ Attention: If there are deep scratches or corrosion on the surface of the block or head, the gasket will burn out again. In this case it is required plane grinding (from craftsmen) or replacing the head.
What to do if the cylinder head bolt breaks?

If the bolt breaks off when unscrewing:

1. Drill a hole in the center of the bolt with a Ø3–4 mm drill.

2. Screw in the extractor (left-hand drill) and unscrew the fragment.

3. Check the threads in the block with a tap. If the thread is damaged, you will need a screwdriver (helicoil).

Installing a new gasket and assembling

New cylinder head gasket being installed only on clean and dry surfaces. Follow the instructions:

  1. Check the gasket. It should be free of burrs, with clear holes for bolts and channels. Compare with the old one - all holes should match.
  2. Place the gasket on the block. Focus on the guide bushings (they should coincide with the holes in the block). Do not use sealant on the surface of the gasket!
  3. Install the block head. Carefully lower it onto the gasket, avoiding displacement. Check that the guide bushings fit into the holes.

Now tightening cylinder head bolts - a critical stage. Use new bolts and a torque wrench. Tightening order:

Stage Moment, Nm Order
1st pass 20–25 Tighten all bolts in an inside-out sequence.
2nd pass 40–45 Repeat in the same order
3rd pass 65–70 Final puff
4th pass (after 10 min) Turn 90° Only for bolts 1–10 (see diagram)

After tightening the bolts:

  • 🔧 Install the camshafts, aligning the marks with the marks on the head.
  • 🔌 Connect all pipes and connectors (use your photos!).
  • 🛢️ Fill in new oil and antifreeze (pre-flush the cooling system).
💡

Before adding antifreeze, unscrew the air bleeder on the thermostat - this will speed up pumping of the system and avoid air locks.

Run-in and check after replacement

After assembly don't start the engine right away! First:

  1. Rotate the crankshaft by hand (with a 22 mm wrench) 2-3 turns to ensure that the pistons do not rest against the valves.
  2. Check the oil and antifreeze levels.
  3. Start the engine and let it idle for 5-7 minutes, observing:
  • 🔥 Temperature (the needle should not rise above the middle of the scale).
  • 💧 Leaks from under the cylinder head or pipes.
  • 🎵 Extraneous noise (knocks or squeaks indicate incorrect assembly).

During the first 500 km adhere to a gentle regime:

  • 🚗 Do not exceed 3000 rpm.
  • 🛑 Avoid sudden acceleration and braking.
  • 🔥 Monitor the engine temperature every 10-15 minutes.
⚠️ Attention: If, after replacing the gasket, the engine continues to overheat or an emulsion appears in the oil again, stop immediately. This is a sign that the bolts are not properly tightened or the head is deformed. Re-disassembly required!
💡

The main break-in rule: the first 100 km - without loads. This will allow the gasket to “settle” and prevent repeated breakdown.

Common mistakes and how to avoid them

Even experienced craftsmen make mistakes when replacing the cylinder head gasket with Nissan Sunny FB15. Here TOP-5 misses and how to prevent them:

  • 🔧 Using old cylinder head bolts. They stretch out when tightened and do not provide the required force. Always take new ones!
  • 🧴 Applying sealant to the entire gasket. It is only needed for oil channels (in a thin layer!). The sealant on the surface of the block will lead to blockage of the channels.
  • 🔩 Violation of tightening order. You cannot tighten the bolts “crosswise” - only according to the “inside-out” pattern!
  • 🧹 Cleaning surfaces with sandpaper. This breaks the flatness. Use only a plastic scraper and solvent.
  • 🚗 Ignoring break-in. Sudden loads in the first 500 km are guaranteed to lead to a breakdown of the new gasket.

Another common mistake is failure to check the head for deformation. If the head “began” due to overheating, it needs to be ground. You can check it yourself:

  1. Place a metal ruler against the plane of the head.
  2. Measure the gap with a feeler gauge. Acceptable value is up to 0.05 mm. If more, the head must be ground.
💡

If you don't have a dipstick, use glass from an old incandescent lamp. Apply it to the plane of the head - if there is a gap, you will see light stripes.

FAQ: Frequently asked questions about replacing the cylinder head gasket

Is it possible to drive with a broken cylinder head gasket if you add antifreeze?

No! Even if you constantly add antifreeze, operation with a broken gasket leads to:

  • 🔥 Overheating and deformation of the block head.
  • 🛢️ Antifreeze gets into the oil and destroys the liners.
  • ⚡ Bullying on the cylinder mirror (due to loss of compression).

The minimum repair in this case is replacing the gasket + grinding the head. Maximum - engine capital.

What sealant should I use for the cylinder head gasket?

For Nissan Sunny FB15 fit:

  • 🧪 Loctite 574 (anaerobic, does not require pre-drying).
  • 🧪 Permatex Ultra Grey (universal, withstands high temperatures).

The sealant is applied only for oil channels thin layer (0.5–1 mm). Apply to the surface of the gasket or block prohibited!

How much does it cost to replace a cylinder head gasket at a service center?

Cost of work in 2026:

  • 💰 On your own: 3–5 thousand rubles. (gasket + bolts + consumables).
  • 💰 In service: 12–20 thousand rubles. (including diagnostics and head grinding if necessary).

The savings on replacement yourself are justified if you have a torque wrench and experience working with engines. Nissan.

What should I do if the engine starts to shake after replacing the gasket?

Reasons for tripping after replacement:

  1. 🔧 Incorrect camshaft installation (timing timing marks are knocked off).
  2. ⚡ Antifreeze getting into the cylinders (cooling system is poorly flushed).
  3. 🛑 Faulty spark plugs or high-voltage wires (check their resistance).

Check first compression And timing marks. If everything is in order, drain the oil and antifreeze, flush the system and replace the spark plugs.

Can I use a cylinder head gasket from another engine?

No! The gasket must be strictly for GA15DE (article 11044-4M000). Analogues from other motors Nissan (For example, GA16DE) are not suitable due to:

  • 🔧 Different diameters of holes for bolts.
  • 🚿 Differences in the location of oil and cooling channels.

Using a non-original gasket will lead to repeated breakdown within 1–2 thousand km.