I wanted a thread to track the headgasket failure on 3rd Gen Prius 2010-2015. Is a headgasket failure a if or just when it's going to fail? I also heard the EGR gets dirt and plugged. Do Prius owners actually services these parts and clean them? Please reply with following: Headgasket: Year of Prius?: How many miles?: How many years of ownership before it happened? Did you replace the headgasket before engine failure? Did you replace engine because it couldn't be saved? EGR: Year of Prius? How many miles before EGR engine code come on? How many years of ownership before EGR started to fail? Was there any problems following the EGR plug? Hopefully this thread will help other 3rd Gen Prius owners track these problems and give an expectation time frame and experience.
unfortunately, threads don't work that way. we have no idea how common it is, because there are millions of prius owners who aren't members here. toyota does not divulge this information. here's my best guess based on spending a lot of time reading posts: it is not a when, but it is an if most egr circuits reported here show some amount of clogging. it is always worth checking. an ounce of prevention... otoh, we are not sure what the actual cause is, because toyota updated the rings in 14 and pistons in 15.
Some additional information has been accumulated over recent months: There are ways you can non-invasively check the flow of your EGR system, and use that to inform whether you dive into a knuckle-busting weekend project "just because", or see an indication that the time has come. We've identified in interesting possible failure mode of the EGR valve actuator, which can be another cause of a low-flow situation, independent of clogging. So the state of knowledge doesn't stay completely static forever. It plods along, just doesn't match the pace of the most avid speculators.
I’m guessing now BOTH pistons and rings were changed at the same time, sometime in model year 2014: apparently new rings don’t work with old pistons, or vice versa.
I've wondered if I have the new rings or pistons in my car (3/29/14). It could be both, neither, or one of them. I still don't know.
