My Prius Plug-in has clocked in 140,000 trouble-free miles. I’m wondering whether I should do a head gasket replacement this summer, to prevent a more expensive failure later. What do you folks think? Crazy? I’ve noticed that no-one mentions replacement of the timing chain or even the timing chain guides with the head gasket job. Is that because those items haven’t been failure prone in the Gen III engine?
You've done the EGR once? More than once? Are you monitoring the EGR pipe? I can't recall if you put in an Oil Catch Can? I think you're on top of it, let sleeping dogs lie? Especially that one just above, lol. I've got a hunch a carboned-up EGR is the main contributor to head gasket failure, due to raised engine temps. Probably a big factor in piston rings carboning-up as well, increasing oil consumption?
I cleaned the EGR pipe twice — was never very bad — and removed/cleaned the whole EGR and intake manifold once. Replaced the PCV and I bought but haven’t yet installed the catch can. I just moved to a state where it’s legal... an OCC is illegal in California, though surely it’s a very minor infraction since it causes no reduction in emissions performance at all.
How much electric-only usage do you have? 140K on a plug-in may not equal 140K in ICE usage. If I was past 200K on a non plug-in and I regularly used the car for long trips to remote areas, your idea of a preemptive head gasket replacement is not entirely unreasonable. But by that time, most of these engines will be oil burners and it may not make sense to repair them at all. The "infraction" is that you will not pass smog.
To pass inspection, f you cut the PCV hose at the middle to splice in an OCC, pick up an extra hose ($8.53*), and remove the OCC temporarily, swap in the other hose, at inspection time. A little absurd, that a mod that does not increase emissions, and likely helps the engine run cleaner, is an infraction. I guess the key is that it's "unvetted", and there are vented versions that are polluting, gives them all a bad name. Also, a poor hose install could be leaky. PCV hose part no: 12261-37060 * Discounted price, before shipping, through: Hose Ventilation N - Toyota (12261-37060) | Toyota Parts Local dealership parts departments will be able to order it in too.
I second what Mendel mentioned above. I'd continue with the periodic EGR system cleanses and do an OCC. Spend your time and money on a scangauge to keep an eye on engine temperatures and water pump RPMs.
The party in office is concerned about the prospective botched OCC installs such as minor leaks & stuff.
California needs vehicle emission controls; no question. Between the high population and the ecology of the Bay Area and LA Basin, smog will reach very unhealthy levels if not controlled; this is a proven fact. So it boils down to how do you legislate it? When you carve out exceptions, people will use them to circumvent smog controls or they’ll accidentally circumvent them; for instance, selling a used car with an OCC, and the new owner doesn’t know about emptying the can, or the lines leak... it’s just very difficult to legislate, that’s all. It’s not because the policy makers are stupid or that they wish to harm people. Clean air is needed for life, and it needs to be protected.
When you say you've cleaned the pipe, you are referring to this part, right? And peered into the abyss...
Yeah a dirty pipe is just an easy part to use as an indicator. The cooler is really the big part to be cleaned. But it’s not a bad idea to check the throttle body for oil and if there is a pool, clean the intake as well. I have my spare engine apart and at 200k miles of 90% ice usage, the timing chain and guides look barely used. So I honestly am not concerned about those items. -Spiral
An Oil Catch Can should stop most of the pooling. Though, when pulling off the intake manifold a second, after cleaning and OCC install, I noticed a tear of oil at each intake port. Maybe due to Atkinson cycle??
