1HZ timing belt
Toyota 1HZ Timing Belt Guide
The Toyota 1HZ is a 4.2L inline-6 diesel engine commonly found in Land Cruiser models, such as the 70 Series, 80 Series, and 100 Series. Known for its durability and reliability, the 1HZ engine uses a timing belt (not a timing chain), which must be replaced periodically to prevent serious engine damage.
1. Does the Toyota 1HZ Have a Timing Belt or Chain?
✅ The Toyota 1HZ engine uses a timing belt.
✅ It is a non-interference engine, meaning if the belt snaps, the pistons and valves will not collide, reducing the risk of severe engine damage.
However, a broken timing belt will cause the engine to stop running, which could be dangerous if it happens while driving.
2. Recommended Timing Belt Change Interval
Toyota recommends replacing the 1HZ timing belt at:
🔹 Every 100,000 km (62,000 miles) or every 5 years, whichever comes first.
👉 Many Toyota owners replace the belt earlier (at 80,000 km) to be extra cautious, especially in harsh conditions (off-roading, towing, or extreme heat).
3. Symptoms of a Worn Timing Belt
⚠️ Signs that your 1HZ timing belt needs replacement:
✅ Cracks or fraying on the belt
✅ Ticking noise from the engine
✅ Difficulty starting the engine
✅ Loss of power or misfires
✅ Check engine light (some models have a timing belt warning light)
Important: The 1HZ engine has a timing belt warning light on the dashboard that comes on at 90,000-100,000 km to remind you to replace the belt. After replacing the belt, this light needs to be reset.
4. Cost of Replacing a 1HZ Timing Belt
🔧 Parts & Labor Cost:
| Service Type | Estimated Cost |
|---|---|
| DIY (Parts Only) | $40 – $150 |
| Mechanic (Parts + Labor) | $200 – $600 |
👉 Recommended Parts to Replace Along With the Timing Belt:
✔ Timing belt tensioner & idler pulley
✔ Water pump (if leaking or due for replacement)
✔ Crankshaft & camshaft seals (if worn)
5. Steps to Replace the Toyota 1HZ Timing Belt
🛠 Tools Required:
- Socket set
- Torque wrench
- Timing belt kit (belt, tensioner, idler)
- Crankshaft pulley removal tool
Basic Steps:
1️⃣ Disconnect the battery to ensure safety.
2️⃣ Remove the radiator fan & belts for access.
3️⃣ Remove the timing belt cover.
4️⃣ Align the timing marks on the camshaft and crankshaft.
5️⃣ Loosen the tensioner and remove the old belt.
6️⃣ Install the new timing belt, ensuring proper alignment.
7️⃣ Reinstall the tensioner and adjust belt tension.
8️⃣ Turn the engine manually to ensure everything is aligned.
9️⃣ Reassemble all removed components and restart the engine.
🚨 Warning: If the timing belt is not installed correctly, the engine may not start or run poorly. If unsure, it’s best to have a professional mechanic do the job.
6. What Happens If the Timing Belt Breaks?
Since the Toyota 1HZ is a non-interference engine, a snapped belt won’t damage the valves or pistons. However, the engine will stop running immediately, which can be dangerous if you’re driving at high speeds or in remote areas.
To avoid unexpected breakdowns, always replace the belt on time.
7. Resetting the Timing Belt Light on a Toyota 1HZ
After replacing the timing belt, you must reset the “Timing Belt” warning light:
Steps to Reset Timing Belt Light:
1️⃣ Locate the timing belt warning light reset switch on the dashboard (near the speedometer).
2️⃣ Press and hold the reset button with a small screwdriver or pin.
3️⃣ Turn the ignition to ON (without starting the engine).
4️⃣ Hold the button for about 5-10 seconds until the light turns off.
5️⃣ Release the button and turn the ignition off.
Now, the light should stay off until the next 100,000 km interval.
8. Conclusion: Should You Replace the Timing Belt?
✅ Yes! Replacing the timing belt at the correct interval is essential for engine longevity and reliability.
🔧 If you’re a DIY enthusiast, the 1HZ timing belt is relatively easy to replace compared to other engines. But if you’re unsure, it’s best to take it to a mechanic.
Would you like a detailed step-by-step guide with pictures? 🚗🔧