Why does nobody talk about how injector tips wear down slowly over time?

I work at a shop in Phoenix and I pulled a set of injectors out of a 2015 Freightliner last month that had 400k miles on them. The tips looked fine from a glance but when I compared them to a brand new set under a magnifying glass the difference was crazy. The orifices had gotten about 15% larger from all the fuel flow and wear. Has anyone else noticed this gradual change causing weird misfire codes that come and go?

3 comments

3 Comments

milesbarnes3h ago

Has anyone checked if that extra fuel flow is washing the oil off the cylinder walls?

caseywalker6h ago

400k miles with 15% bigger holes sounds like your injectors turned into fuel straws, no wonder the ECM is throwing a fit.

finley_smith5h ago

400k miles is crazy. That truck is basically held together with hopes and dreams at this point. Caseywalker, you're right, those injectors are probably just dumping fuel straight into the cylinders now. I bet his fuel economy is measured in gallons per mile instead of miles per gallon. The ECM is probably running on pure confusion. It's seeing a massive fuel leak and trying to compensate, but the poor thing doesn't know what to do anymore. Probably smells like a gas station every time he starts it up.