How to judge and eliminate the noise caused by the self-locking ability of connecting rod bolts and nuts?

After the car has been used for a period of time, some parts of the car will inevitably become loose, and then make noises. When encountering similar situations, many novice drivers and friends don't know how to check and eliminate, and then we will self-lock the connecting rod bolts and nuts. Let’s talk about the specific judgment and exclusion methods caused by the noise caused by the reduction of ability.

Judging and troubleshooting methods for the reduction of self-locking ability of connecting rod bolts and nuts: (Guide: Common loosening problems of threaded fasteners, anti-loosening measures, anti-loosing structure)

① Carry out spark plug misfire experiment cylinder by cylinder, and find out the cylinders that reflect the upper cylinder. When the nut is severely loosened, the upper cylinder may be reversed. In this way, you can avoid detours and find faults quickly. A similar situation occurs when the connecting rod bearing alloy is severely dropped. Therefore, if there is an anti-loading situation, there are generally more serious failures. You should stop and check immediately, and you can't make do with it.

②For the cylinder with the reverse upper cylinder, you can further check: remove the spark plug of the cylinder, shake the crankshaft to make the piston reach the top dead center, and then go down about 4mm, and then use a screwdriver to extend into the spark plug hole to move the piston toward the top dead center. Press down. If the piston moves down significantly at this time, accompanied by a metal knocking sound, it can be judged to be such a fault. Please note: This situation may also occur when the piston is off the top. The main difference is that the piston off the top and the connecting rod will be seriously out of sync, and even when the crankshaft rotates, the top of the piston does not move at all.

For the above failures, the connecting rod bolts and nuts should be replaced in time, and the connecting rod bearings and connecting rod bushings should be replaced as appropriate.

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