Injector Protector 119802-11870

Function and technical context

The injector protector with reference 119802-11870 is a component of the fuel injection system in Yanmar diesel engines, designed to protect the injector housing in the cylinder head against galvanic corrosion, extreme heat and carbon deposits that accumulate in the contact area between the injector and the combustion chamber. Its function is to act as a sealing and thermal-mechanical insulation element between the body of the injector and the seat of the cylinder head, preventing high-temperature combustion gases from damaging the surrounding metal and compromising the tightness of the assembly. If this protector deteriorates, a gas leak, faulty injector installation or damage to the cylinder head may occur, leading to high-cost repairs. 4 units per engine are required on 4JH series models.

When to replace this part?

Common symptoms of injector guard deterioration include visible gas leaks around the injector, difficulties in removing the injector during maintenance due to sticking or corrosion on the seat, and excessive carbonization in the housing area. It is recommended that these guards be inspected and replaced each time an injector is removed or replaced, as well as at each seasonal inspection on engines with many hours of work. Replacing them preventively along with the injectors prevents more serious damage to the cylinder head and guarantees correct installation of the injection system.