About the 4M40 Engine
The 4M40 engine is a diesel engine produced by Mitsubishi Motors. It is a four-cylinder, turbocharged engine commonly used in various Mitsubishi vehicles, including the Pajero, Delica, and Canter. Known for its durability and reliability, the 4M40 engine is often favored for its strong performance and fuel efficiency. Regular maintenance is essential to keep the engine running smoothly, and one critical aspect is ensuring the proper torque settings for the head bolts. This article will provide you with the necessary information on the head bolt torque settings for the 4M40 engine.
Head Bolt Torque Settings for the 4M40 Engine
To ensure the proper sealing and integrity of the engine’s cylinder head, it is crucial to tighten the head bolts to the correct torque specifications. The table below provides the recommended head bolt torque settings for the 4M40 engine in both foot-pounds (ft. lbs.) and Newton-meters (Nm):
| Head Bolt | Torque Specification (ft. lbs.) | Torque Specification (Nm) |
|---|---|---|
| 1 | 29-33 | 39-45 |
| 2 | 29-33 | 39-45 |
| 3 | 29-33 | 39-45 |
| 4 | 29-33 | 39-45 |
| 5 | 59-64 | 80-87 |
| 6 | 59-64 | 80-87 |
| 7 | 59-64 | 80-87 |
| 8 | 59-64 | 80-87 |
Procedure for Torquing the Head Bolts
To properly torque the head bolts on the 4M40 engine, follow these steps:
1. Begin by cleaning the threads of the head bolts and the bolt holes in the engine block to ensure proper engagement and accurate torque readings.
2. Apply a small amount of engine oil to the threads of each head bolt.
3. Start with bolt number 1 and tighten it to the specified torque using a torque wrench. Gradually increase the torque in three equal steps, reaching the final torque specification.
4. Repeat the process for bolts 2, 3, and 4, following the same torque sequence and steps.
5. For bolts 5, 6, 7, and 8, use a higher torque specification and follow the same tightening sequence and steps.
6. Once all the head bolts are torqued to the specified values, recheck each bolt’s torque to ensure accuracy.
7. Finally, double-check the torque sequence and values before proceeding with further assembly.
Importance of Proper Head Bolt Torque
Properly torquing the head bolts is crucial to maintain the integrity of the engine’s cylinder head gasket. Insufficient torque can result in inadequate sealing, leading to coolant leaks, loss of compression, and potential engine damage. On the other hand, over-tightening the head bolts can cause distortion or even fracture the cylinder head. Therefore, following the recommended torque settings is essential to ensure the longevity and performance of the 4M40 engine.
By adhering to the specified head bolt torque settings and following the correct torquing procedure, you can ensure the proper sealing and integrity of the 4M40 engine’s cylinder head. Regular maintenance and attention to torque specifications will contribute to the engine’s longevity and reliable performance.