Engine GA15DE (known as FB15 in the back Nissan Sunny N15/B15) is famous for its reliability, but even it is not immune to typical problems with age. One of them is wear and tear. valve stem seals (valve seals), which leads to increased oil consumption, smoke from the exhaust pipe and oiling of the spark plugs. If your Sunny started to “eat” liters of oil, and the compression is normal - the culprit with a 90% probability is the caps.
In this article we will look at step-by-step replacement of valve stem seals on FB15 without removing the cylinder head (cylinder head), taking into account the design nuances GA15DE. You will learn what tools are needed, how to avoid mistakes during disassembly, and why some craftsmen recommend changing caps only paired with valve guides (spoiler: this is not always justified). We will also analyze whether it is worth taking on the work yourself or whether it is better to trust the service.
Signs of wear on oil seals on Nissan Sunny FB15
Symptoms of "tired" caps are often confused with problems with the piston rings or turbine (if there is one). However, GA15DE There are specific “bells” that help accurately diagnose a malfunction:
- 🔥 Blue smoke from the exhaust pipe when starting cold (disappears after 10–30 seconds). This oil, which has accumulated in the combustion chamber overnight, burns out during the first start-up.
- 🛢️ Oil consumption 1–3 liters per 1000 km no visible leaks. The caps allow oil to pass into the cylinders, where it burns along with the fuel.
- 🕯️ Oily spark plug electrodes. If there is black carbon deposits with an oily sheen on the threads or insulator of the spark plug, this is a direct sign.
- 🚗 Power loss at high speeds. Oil in the combustion chamber worsens the knock resistance of the fuel mixture.
It is important to distinguish these symptoms from wear and tear piston ringswhich produce constant smoke (including on a hot engine) and decreased compression. On FB15 With mileage >200 thousand km, a combined problem often occurs - both caps and rings. You can check this oil burn test: If the smoke disappears after warming up, the caps are to blame; if it remains, rings.
⚠️ Attention: On Nissan Sunny FB15 with GA15DE after 2000, caps were sometimes installed green (instead of standard black ones). They are more rigid and last longer, but when replacing they should not be confused with analogues for other engines Nissan (For example, SR20DE).
Tools and consumables: what is needed for replacement
To work you will need specialized tool, without which it is impossible to remove and install the caps without damage. Here's the full list:
| Category | Name | Notes |
|---|---|---|
| Special tools | Oil seal remover | For GA15DE A universal puller with a collet grip is suitable (for example, Lisle 65600) |
| Consumables | Set of caps (16 pcs.) | Original - Nissan 13270-4M000 (black) or 13270-4M001 (green). Analogues: Nipparts J1301004, Elring 523.060 |
| General tool | Set of heads and knobs | A 10 mm socket (for the cylinder head cover) and an extension are required |
| Additionally | Tin or soft wire rod (∅8–10 mm) | For fixing valves in the upper position when removing crackers |
| Other | Sealant for cylinder head cover | Recommended ThreeBond 1215 or analogue (not silicone!) |
Also prepare torque wrench (for tightening the cylinder head cover with a torque of 8–10 Nm) and pneumatic compressor (if you blow out the cylinders to fix the valves). You can do without a compressor, but this will complicate the process.
- Yes, on a Nissan Sunny
- Yes, on a different car
- No, but I plan to
- No and I won't
Engine preparation: removing the cylinder head cover and timing belt
Before starting work necessarily drain the oil and antifreeze (if you are removing the pump or pulleys). Next, follow the algorithm:
- Remove air filter and a pipe from the throttle to the filter.
- Disconnect throttle cable and sensor connectors (temperature sensors, mass air flow sensor, temperature sensor).
- Dismantle cylinder head cover (10 10mm head bolts). Be careful - there may be washers underneath!
- Install the piston 1st cylinder at TDC (top dead center) according to the marks on the crankshaft and camshaft pulley.
- Loosen the tensioner and remove timing belt. On GA15DE it goes through the pump, so check its play.
Important: if you do not plan to change the timing belt, mark its direction of rotation marker and secure the camshafts from turning (for example, with a stopper or a homemade bracket). On FB15 misaligned valve timing will lead to collision of valves with pistons!
What happens if you don't fix the camshafts?
On the GA15DE, when turning the camshafts without a timing belt, the valves can hit the pistons, which will lead to bending of the valves and repair of the cylinder head at a cost of 50+ thousand rubles.
Removing valve springs and replacing caps: step-by-step instructions
This is the most critical stage. The important thing here is not to damage valve guides and not lose crackers (they are small and easily “fly away” when removed). Proceed like this:
Make sure the piston is at TDC|Place a tin rod on the valve plate|Place the puller on the cap and secure it|Blow out the cylinder with compressed air (optional)-->
1. Valve fixation. Insert a tin rod into the spark plug hole and press it against the valve plate. This will prevent the valve from falling into the cylinder when removing the cotters.
2. Spring compression. Use valve depressurizer (For example, Hazet 2069-2). Compress the spring until the crackers are released from the plate.
3. Removing breadcrumbs. Gently remove them with a magnet or tweezers. Don't drop it! If a cracker falls into the cylinder, you will have to remove the head.
4. Removing the cap. Place the puller on the cap and lightly hit the handle with a hammer to remove it from the guide. If the cap is stuck, do not pull it by force - wet it WD-40 and wait 10 minutes.
5. Installing a new cap. Before installation, lubricate the inner surface of the cap motor oil (this will make installation easier). Place it on the guide and press it in with the puller until it stops.
Repeat the process for all 16 valves. On GA15DE the caps on the intake and exhaust valves are the same, but some experts recommend installing more heat-resistant ones on the exhaust valves (for example, Goetze with a blue mark).
Before installing new caps, check the valve play in the guides. If it exceeds 0.5 mm, the bushings need to be replaced (otherwise the caps will quickly wear out again).
Common mistakes and how to avoid them
Even experienced craftsmen sometimes make mistakes when replacing caps on FB15. Here are the most common:
- 🔧 Re-upholstery of the cylinder head cover. The tightening torque is 8–10 Nm, and not “from the heart.” Otherwise, the cover will become deformed and oil will leak through the gasket.
- 🔄 Incorrect timing belt installation. On GA15DE the marks must match: the crankshaft is at 0°, the camshafts are at “I” (intake) and “E” (exhaust).
- 🛑 Ignoring crackers. If a cracker falls into the cylinder, you can try to remove it with a magnet through the spark plug hole, but more often you have to remove the cylinder head.
- 🔥 Operation without fixing the valves. Without a tin rod or compressed air, the valve will fall into the cylinder and will have to be “caught” with an endoscope.
Another typical problem is damage to camshaft seals when removing the cylinder head cover. On FB15 they often “stick” to the shaft. To avoid this, before removing the cover, carefully pry the seals with a screwdriver and spray WD-40.
⚠️ Attention: After replacing the caps, the engine may smoke a little for the first 500 km - this is normal, as the oil burns out from the cylinder walls. If the smoke has not disappeared after 1000 km, check the correct installation of the caps or the tightness of the guide bushings.
Should I change the caps myself or trust the service?
Replacing oil seals with Nissan Sunny FB15 - a task of medium complexity. If you have experience with engine repairs (such as adjusting valves or replacing head gaskets), you can do it in 6-8 hours. Beginners will have to spend 10–12 hours, and the risk of errors increases.
Cost of work in the service:
- 💰 On your own: 3–5 thousand rubles (caps + consumables).
- 💰 Service: 12–18 thousand rubles (with labor and spare parts).
Is it more profitable to do it yourself? Yes, if:
- 🔧 You have a special tool (puller, desiccant).
- ⏳ You are not limited in time (the work stretches for 1-2 days).
- 🔍 You are ready for possible “surprises” (for example, broken crackers).
If at least one point is not fulfilled, it is better to contact the service. On GA15DE There are often pitfalls:
- 🔩 Coked caps (you have to drill it out).
- 🔄 Broken timing marks (if you do not fix the shafts).
- 🛢️ Oil leak after assembly (if you tighten the cylinder head cover).
If the mileage of your Sunny exceeds 250 thousand km, it is worth replacing the valve guides and camshaft seals at the same time as the caps. This will increase the cost of repairs by 30-40%, but will save time and money in the future.
FAQ: Frequently asked questions about replacing valve stem seals on FB15
Is it possible to replace the caps without removing the cylinder head?
Yes, on GA15DE this is possible due to the design of the engine. However, this requires special puller and ability to work with valve springs. Without experience, it is better to remove the head - this way there is less risk of damaging the guides.
Which caps are better - original or analogues?
Original (Nissan 13270-4M000) last longer, but cost 2–3 times more than analogues. A good alternative is Goetze or Elring. You can take it from the budget ones Nipparts, but their resource rarely exceeds 50 thousand km.
Do I need to adjust the valves after replacing the caps?
On GA15DE valve clearances are adjustable only with washers (no hydraulic compensators). If you did not remove the camshafts or change the washers, no adjustment is required. But check the gaps after 1000 km - they could have changed due to wear on the cams.
After how many km do the caps need to be changed?
The service life of original caps is 150–200 thousand km. Analogs last 80–120 thousand km. If the engine often runs at high speeds or low-quality oil is used, the interval is reduced to 100 thousand km.
Is it possible to drive with worn caps?
Technically yes, but this leads to:
- Increased oil consumption (up to 1–2 liters per 1000 km).
- Contamination of the catalyst (if any).
- Accelerated wear of piston rings due to oil starvation.
If you ignore the problem, after 30–50 thousand km you may need major renovation.