Frequently Asked Questions

My injector failed. What are the reasons why these fail and what can I do to prevent it from happening again?

A. The key cause of injector failures are:

Poor fuel filtration
A common problem with diesel injectors today is ball seat erosion. The heart of the common rail injector is the magnetic valve through which fuel passes at extremely high pressure. The passage opening is sealed using a small ball that is only 1mm in size. A proper seal is critical for proper injector performance. Abrasive contaminants can erode and damage the ball seat causing the ball not to seal properly leading to improper injection.

To ensure exact performance within the designed service life of the injector, use only OE filters or filters having the same OE micron rating and follow the recommended OE filter change interval. Using anything less can cost you more in the long run.

Fuel contamination
Repair statistics show that the majority of diesel engine problems stem from contaminated fuel. One of the most common problems with diesel injectors is corrosion, which is caused by water in the fuel. How does the water get into the fuel? A vented cap allows air to enter the storage tank to equalize pressure as the fuel flows out. The outside air contains moisture and this moisture condenses into water inside the tank.

Always purchase fuel from a reputable service provider and use a proper fuel/water separator.

Incorrect installation
​Missing sealing rings, incorrect tightening torque, incorrect cleaning of nozzle can cause poor performance, misfiring, black smoke and check engine light (MIL) to come on. Always follow the engine manufacturer’s maintenance procedures.


What does “remanufactured” mean?

A. Remanufactured does not mean “used” or “rebuilt”. It means that the part has been manufactured again. 100% of all parts are examined and the non-wearable parts – such as the injector body – are re-used. However, if there are any flaws, the part is discarded. The injector is rebuilt and all wearable components are replaced. The part is then tested before completion. The extent of the remanufacturing and testing process depends on the manufacturer.


Aren’t all remanufactured injectors the same? Does it matter which one I choose?

A. Not all remanufactured injectors are the same. The quality of any remanufactured injector depends on the remanufacturing process. Bosch’s remanufactured injectors are exactly the same as OE injectors in design, engineering, materials, manufacturing and quality control. Bosch remanufactured injectors include all OE updates, so they can often be superior to the OE injectors that they replace.

Bosch common rail injectors are the only ones that are validated to OE manufacturing standards and specifications.


I found a cheaper injector online. Can I purchase and have my diesel mechanic install it?

A. The old adage “you get what you pay for” applies here. Bosch tests all remanufactured parts to OE specifications. Cheaper alternatives can potentially cut corners, limiting the life of the injector and compromising the performance. For example, refinishing vs. replacing a control valve piston can compromise the fit which controls leakage and affects stability. It is better to invest in a quality part that won’t leave you stranded or worse – cause expensive damage to your engine.