Replacing valve stem seals on a Nissan Murano Z50: when is it needed and how to do it right

Replacement valve stem seals on Nissan Murano Z50 (first generation, 2003–2007) - a procedure that many owners put off until the last minute, until the engine literally begins to “eat oil.” Meanwhile, worn valve seals lead not only to increased oil consumption, but also to the formation of carbon deposits on the pistons, clogging of the catalyst and even risk of water hammer during cold startif oil has accumulated in the cylinders. In this article we will look at how to diagnose the problem, which caps to choose for VQ35DE (3.5 l) and VQ25DE (2.5 l), and we will also describe in detail the replacement process, taking into account the nuances of this particular crossover.

Is it worth going to a service center or can you handle it yourself? If you have experience repairing cylinder head or at least basic skills in working with tools, the task is quite doable in the garage. The main thing is not to rush and take into account all the pitfalls, which we will discuss below. And for those who doubt, here is a comparison of the cost of work in the service and independent replacement: the difference can reach 20–30 thousand rubles.

Signs of worn valve stem seals on a Nissan Murano Z50

The first and most obvious symptom is increased oil consumption (more than 1 liter per 1000 km). But there are other “bells” that are often ignored:

• 🔵 Blue smoke from the exhaust pipe when you press the gas sharply (especially after a long period of inactivity). This is oil that burns in the chamber along with the fuel.
• 🔥 Carbon deposits on spark plugs. If the electrodes are covered with a black oily coating, the caps are definitely “tired”.
• 🛢️ Oil in the air duct (check the pipe from the valve cover to the throttle body). If there are oil deposits, the seals are leaking.
• 🚗 Engine tripping to cold. Oil that accumulates in the cylinders overnight interferes with normal combustion.

On Nissan Murano Z50 with motor VQ35DE (the most common option) wear of the caps often appears after 150–200 thousand km. But if the car was operated under difficult conditions (frequent cold starts, aggressive driving, low-quality oil), the problem may arise earlier. The caps on cylinders 1 and 4 are especially vulnerable - the temperature is higher there and the rubber hardens faster.

⚠️ Attention: Don't confuse symptoms of cap wear with piston ring problems! With rings, the oil flows out evenly and the smoke comes out constantly, and not just when changing gases. A compression test or an endoscope will help accurately diagnose.

If you ignore the problem, the consequences will be serious:

• 🔥 Poisoning of piston rings due to carbon deposits.
• 💥 Destruction of the catalyst (oil burns with the formation of soot).
• 🛑 Risk of water hammer during a cold start (if oil has accumulated in the cylinder).

Which valve stem seals to choose for Nissan Murano Z50

There are three cap options on the market for VQ35DE/VQ25DE:

Brand	Article	Price per set (16 pcs.)	Features
Nissan OEM	13270-4M000 (VQ35DE) 13270-5M000 (VQ25DE)	3 500–4 200 ₽	Original, best quality rubber, but often counterfeited.
Nipparts	NIP-132704M000	2 800–3 300 ₽	A good analogue, soft rubber, suitable for harsh climates.
Ajusa	14018600	2 200–2 600 ₽	A budget option, but the tires are harder and can leak after 50–60 thousand km.
Elring	444.170	3 000–3 500 ₽	German quality, long service life, but rarely found in stores.

For Nissan Murano Z50 we recommend original or Nipparts. Ajusa and other cheap analogues often lead to repeated replacement after 30–50 thousand km. Please note cap color: original - black with gray O-ring. If you are offered completely black or brown ones, it is a fake or a low-quality analogue.

Also, when purchasing, check:

• 📦 Packaging — the original must have a hologram and an article number stamped on plastic.
• 👆 Rubber hardness — the caps should not feel “oaky” to the touch.
• 🔍 Presence of spring - it should be smooth, without jagged edges.

Tools and preparation for replacement

To work you will need:

• 🔧 Set of heads and knobs (10, 12, 14 mm).
• 🔨 Torque wrench (for tightening the cylinder head bolts).
• 🛠️ Oil seal remover (or needle nose pliers).
• 🔩 Valve desiccant (can be rented).
• 🧲 Magnetic stick (to extract crackers).
• 🧴 Valve cover sealant (For example, Loctite 574).
• 🔥 Gas burner or hair dryer (to heat the caps during installation).

Also prepare:

• 📋 Marker - to mark wires and hoses.
• 🧹 Rags and carburetor cleaner - for cleaning the cylinder head.
• 🚗 Jack and stands — if you remove the wheel to access the timing belt.

Before starting work:

1. Drain the oil and antifreeze (if you are removing the cylinder head).
2. Disconnect the negative terminal of the battery.
3. Remove the ignition coils and intake manifold (on VQ35DE this is mandatory).

Drain the oil and antifreeze|Disconnect the battery|Remove the ignition coils|Mark the wires and hoses|Clean the cylinder head from dirt-->

⚠️ Attention: On Nissan Murano Z50 with VQ35DE When removing the valve cover, the plastic guides of the spark plug wells often break. Buy spares in advance (22442-JK00A) or carefully remove the cover by prying it off with a screwdriver.

Step-by-step instructions for replacing valve stem seals

The process is labor-intensive, but if you follow the steps, everything will work out. The main thing is do not drop the crackers into the cylinders and do not mix up the assembly order.

Step 1: Removing the Valve Cover and Camshafts

1. Remove the air duct, throttle body and intake manifold.

2. Unscrew the valve cover bolts (8 pcs.) and carefully remove it. If it sticks, pry it off with a screwdriver, but do not force it so as not to break it.

3. Install the piston of the 1st cylinder to TDC (place marks on the crankshaft and camshaft pulley).

4. Unscrew the camshaft mounting bolts (2 bolts for each shaft) and remove them. Do not turn over the shafts - can damage the bed.

Step 2: Removing Valve Springs and Keepers

1. Place the desiccant onto the valve spring and compress it until the crackers are released.

2. Using a magnetic stick, remove the crackers and carefully remove the spring plate.

3. Remove the spring and oil seal. If it is “stuck”, pry it off with a thin screwdriver or a special puller.

What to do if a cracker falls into the cylinder?

If the cracker does fall, don't panic. Using a magnet or tweezers, carefully remove it through the spark plug hole. If that doesn’t work, remove the block head and take it out from below. Under no circumstances try to “push” the cracker with the piston - this will lead to scuffing on the cylinder bore!

Step 3: Installing New Caps

1. Before installing new caps Lubricate their inner surface with engine oil.

2. Place the cap on the valve guide and carefully press it in until it stops (you can use a tube of a suitable diameter).

3. If the cap is tight, heat it with a hair dryer - the rubber will become softer.

4. Install the spring, plate and dry the valve with a desiccant.

Step 4: Assembly and Testing

1. Install the camshafts in place, aligning the marks. Tighten the bolts with a torque wrench until 10–12 Nm.

2. Apply sealant to the valve cover and install it. Tighten the bolts crosswise with force. 8–10 Nm.

3. Reassemble the remaining components in reverse order.

4. Fill with new oil and antifreeze, start the engine. For the first 5–10 minutes it may stall - this is normal (oil burns out of the cylinders).

Common mistakes and how to avoid them

Even experienced craftsmen sometimes make mistakes when replacing caps on Nissan Murano Z50. Here are the most common:

• 🔧 Retightening camshaft bolts. This leads to deformation of the beds and knocking of the shaft. Always use a torque wrench!
• 🔥 Installing caps without lubrication. Dry tires may tear when first started.
• 🛑 Timing timing marks mismatch. If the belt jumps, the valves will meet the pistons. Always check the marks after assembly.
• 🧲 Loss of crackers. If the cracker remains in the cylinder, it must be removed - otherwise it will damage the piston.

Another typical problem is oil leak after change. Most often this happens due to:

• Poor quality sealant on the valve cover.
• The cover is skewed when tightening the bolts.
• Damage to the intake manifold gasket (on VQ35DE she often tans).

⚠️ Attention: After replacing the caps, avoid high speeds (more than 3000 rpm) for the first 500 km. This is necessary for the new caps to “grind in” to the guide bushings.

Cost of work: service vs independent replacement

Prices for replacing valve stem seals Nissan Murano Z50 vary greatly depending on the region and service:

Type of work	Cost in service (₽)	On your own (₽)
Replacing caps (without removing the cylinder head)	15 000–25 000	3,500–4,500 (spare parts)
Replacing caps (with removal of cylinder head)	30 000–50 000	4,000–5,000 (spare parts + sealant)
Replacing caps + guide bushings	40 000–60 000	6 000–7 000
Diagnostics (compression test, endoscope)	2 000–5 000	0 (if there is a compression gauge)

As you can see, replacing it yourself allows you to save money. 10–40 thousand rubles. However, if you are not confident in your abilities, it is better to trust the professionals - mistakes when working with the cylinder head are very expensive.

FAQ: Frequently asked questions about replacing valve stem seals

Is it possible to replace the caps without removing the cylinder head?

Yes, on Nissan Murano Z50 it is possible, but difficult. You need to use a special puller and be very careful not to drop the crackers. If you have little experience, it is better to remove the head - it’s more reliable.

How long does it take to replace?

Service time: 4–6 hours. On your own (for the first time) – 8–12 hours with breaks. The main thing is not to rush and check every step.

What kind of oil should I fill in after replacing the caps?

For VQ35DE fits 5W-30 or 5W-40 with permission API SN or ILSAC GF-5. For example, Nissan Strong Save X 5W-30 or Mobil 1 ESP 5W-30.

After how many km do I need to change the caps again?

High quality caps (original or Nipparts) serve 100–150 thousand km. Cheap analogues - 30–50 thousand km. Service life also depends on driving style and oil quality.

Is it possible to drive with worn caps?

It is possible, but not advisable. Risks: increased engine wear, catalyst clogging, water hammer. If the oil consumption is more than 1 liter per 1000 km, change the caps immediately!