I believe they are what the injectors seat into. But, I am not even sure of that. How long do they last and what makes them go bad?
clydesdale
The injector cup is a brass cup, that is press fit into the injector bore...
It separates the engine coolant from the injector.
Aside from just being "press fit" into the inj bores, a hydraulic (LocTite-type) sealant is used for a better seal than just the press to keep the ~16psi of coolant out of the injector bore.
They typically go bad in a few ways...
heating cycles will cause the Loc-Tite to degrade and lose its' sealing properties...but they are usually 'good' for a couple hundred thousand miles.
OVER-heating (run out of coolant & overheat the cyl head) is another way to cause the cup/sealant to fail...as well as just normal metal fatigue.
the cups aren't directly exposed to combustion...but they are a mere .200"+/- away from the combustion..and pressure within the cylinder...and years upon years, and a few hundred thousand miles can cause the brass to fatigue and crack.
fuel in the coolant system is a BIG clue that you have cup issues.
take care~
Dave
It separates the engine coolant from the injector.
Aside from just being "press fit" into the inj bores, a hydraulic (LocTite-type) sealant is used for a better seal than just the press to keep the ~16psi of coolant out of the injector bore.
They typically go bad in a few ways...
heating cycles will cause the Loc-Tite to degrade and lose its' sealing properties...but they are usually 'good' for a couple hundred thousand miles.
OVER-heating (run out of coolant & overheat the cyl head) is another way to cause the cup/sealant to fail...as well as just normal metal fatigue.
the cups aren't directly exposed to combustion...but they are a mere .200"+/- away from the combustion..and pressure within the cylinder...and years upon years, and a few hundred thousand miles can cause the brass to fatigue and crack.
fuel in the coolant system is a BIG clue that you have cup issues.
take care~
Dave
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