What is the reason for the diesel engine decompression not working?

[Haley]

The reasons why the diesel engine decompression is not working are: 1. The ambient temperature is too low; 2. The fixing screws of the valve cover are loose; 3. The decompression device is severely worn; 4. The decompression spring is dislocated; 5. The valve is in an open or faulty state. Solution: There is a large tightening nut on the decompression valve. Loosen it and use an open-end wrench to rotate the shaft. The shaft has an eccentric amount. Adjust it so that the engine has compression without pulling the handle, and the decompression works when the handle is pulled down. Then fix the shaft and tighten the nut. A diesel engine is an engine that burns diesel to obtain energy release. Its advantages are high torque and good economic performance.

[GabrielaFitz]

I've been repairing diesel engines for many years and found that when decompression doesn't work, it's mostly due to decompression device issues. The most common problems are broken springs or jamming, especially in cold weather when thermal expansion and contraction can cause metal components to stick. Severe connecting rod wear can also lead to decompression failure, while loose control rods and valve blockages are frequent culprits. I recommend first checking for rust or lack of lubrication at the connecting rod joints, and manually testing if it can move. If not, it needs to be disassembled for cleaning or part replacement. Don't force this job yourself—it's best handled by a professional repair shop because starting a diesel engine without decompression is very strenuous and can damage the engine if forced. Regular maintenance like cleaning carbon deposits and adding lubricants can significantly reduce failures.

[VanIan]

I've been driving diesel trucks for over a decade and have encountered several instances of decompression failure. One winter morning, the engine failed to start, and I discovered severe wear on the decompression lever linkage, causing the valve to jam. The main culprit was inadequate maintenance, such as insufficient engine oil leading to increased friction and rapid corrosion. The decompression function helps reduce the load during startup; when it fails, you might need to crank the engine multiple times, sometimes even seeing white smoke, which can significantly damage engine components. Remember, maintaining proper lubrication is key. Inspect the decompression components every six months, and if you notice stiffness or unusual noises during operation, address it immediately. For safety, never overlook minor issues when parking, especially before long trips—test the decompression operation several times to ensure smooth startups.

[Nigel]

I've been driving a diesel car for a short time, and the decompression isn't working properly, possibly due to old age or dirt. For example, the decompression lever might be stuck due to dust accumulation, or the valve might be rusted and immobile, especially in cold weather when problems are more likely to occur. Simply put, regular cleaning and lubrication can prevent this. If it fails, don't force a start to avoid engine damage. Just drive straight to the repair shop and let the mechanic check it out.

[MaggieMarie]

I enjoy DIY repairs on diesel engines. Ineffective decompression is usually a mechanical issue, such as a loosely installed decompression valve or internal rust causing it to stick. When working on it, first disconnect the power, then manually check the flexibility of the decompression mechanism. If it's stiff, it indicates a lack of lubrication or wear, requiring grease application or spring replacement. A bent connecting rod can also cause malfunction, so ensure proper alignment during reassembly to avoid misalignment. Avoid testing during startup as it's highly dangerous. A common mistake is insufficient engine oil accelerating wear; regular maintenance and cleanliness can extend its lifespan. Once, I fixed my neighbor's car, saving a lot on repair costs.