Correctly applying torque to engine fasteners is critical to maintaining engine integrity and reliability. Engine parts such as cylinder heads, main bearing caps, and intake manifolds are engineered to require exact torque values. Too little torque can lead to leaks, component movement, or even catastrophic failure. Too much torque can stretch or break bolts, strip threads, or warp critical surfaces.

Start your process using an accurate torque measuring device. Any of the three common wrench types—beam, click, or digital—can be used, but ensure it’s been recently calibrated and matches your required specs. Do not rely on air or electric impact wrenches to finish tightening unless the manual permits it, as it can easily over-torque fasteners.

Consult the factory service manual for لوازم یدکی چری تیگو 7 پرو precise torque values. These values are not arbitrary—they are calculated based on bolt material, thread size, lubrication, and component design. 3, then full torque. Others may require a torque-to-yield sequence, where the bolt is tightened to a specific torque and then turned an additional number of degrees. Always follow the specified sequence.

The presence or absence of lubricant dramatically affects clamping force. Torque ratings are calibrated for oiled or greased fasteners. If the bolt is dry, the actual clamping force can be significantly higher than intended, increasing the risk of bolt failure. Follow the manual’s directive: apply engine oil, assembly grease, or anaerobic sealant to both threads and bearing surface. When the manual forbids lubrication, leave the bolt completely dry.

Adhere strictly to the factory tightening sequence. Head fasteners require a methodical approach, not arbitrary tightening. There is usually a specific sequence, often starting from the center and working outward in a crisscross pattern. An improper pattern can lead to uneven compression and distortion of aluminum or cast iron surfaces.

Always replace torque-to-yield bolts. Once stretched, they no longer provide consistent clamping force. Reinstalled stretch bolts often fail under heat and pressure due to lost tension.

Verify every fastener after torquing. Once the sequence is complete, re-inspect every bolt to confirm torque values and eliminate omissions. Some alloys and gaskets require a settling period before final torque verification.

The extra effort in torque discipline avoids catastrophic failures and delivers peak engine performance. If specifications are unclear, refer to OEM documentation—never rely on intuition.