2012 bought with 157k miles

I would not start with high mileage oil; see how it goes first. As you say, once you start with that stuff it’s best to stick with it.

 

have you called the dealerships and ask what they would use for your car/milage ?

send off a sample for testing. then you'll know if it's time to fix something of just drive it, as opposed to worrying.

 

toyota does not recommend anything beyond the initial oil when new, to my knowledge.

you have to dive deeper than the dealer or manufacturer.

 

i'm mean due diligence on high mileage oils from reputable sources, if thatis the direction you're considering.

 

Confident in that Dealer shmealer? I wouldn’t be confident of their knowledge if he said high mileage formulation doesn’t come in 0w-20. In fact, I’d delete the number from my outbound recent calls and never speak of it again.

 

You could go with the new GF6-A spec for a better oil. Not GF6-B.

It is not a given that a dealer or oil change pace will use GF-6A. Most will probably give you a deer in the headlights look. First licensing date and use of GF-6A was May 1, 2020.

"GF-6 motor oils will deliver the following performance benefits: improved fuel economy and lower emissions, better deposit control, and greater protection against timing chain wear and Low Speed Pre-Ignition (LSPI)."

The problem with these engines is not really age related wear. Usually blown engines have little or no bearing wear because they always had full synthetic (although some dealers may have used bulk synthetic blends).

The poor piston and piston ring design in our 2010-14 engines often lead to stuck rings. Toyota knew they were bad and offered warranty replacements during the powertrain warranty, but only if you lost a quart in 1200 miles.

When rings are stuck in their groves they tend to cause uneven wear in the cylinder which starts excessive oil consumption. Once started it gets worse. Increased blowby results from larger piston ring to wall clearances which results in more pcv and egr hydrocarbons in the intake manifold. Leaking head gaskets often result which may lead to hydrolock for the fake facts crowd. Then a rod can break causing mass destruction including a hole in the block.

Changing the oil frequently may keep the rings from sticking.

 

Remember service advisors are on commission and are not mechanics

Pretty much just like yours. The MIG electric motor spins the engine to a much higher rpm than a traditional starter which makes it start faster and smoother. Hard to feel if you are driving but you know it when you are not moving.

 

One of the earlier posts looked like it was about the "other" Prius brake issue, the one where rotors get rusty and sound terrible after being parked in the damp. If we put the brake problems in order by prevalence, this one's on top: I have never (yet!) had to replace an actuator or accumulator on any Prius I've owned, but I have to deal with the horrid scraping sound every time I drive after a night in the rain.

Of course that's not an expensive issue. It goes away just through doing enough friction braking to clean off the rotors. The quick way, if I am driving away and notice the scraping sound, is to shift into neutral for the next couple of stops. No need to brake extra hard; using neutral forces those stops to be done entirely with friction.

It is an expensive issue if you're unaware of it. There was a thread here where an owner posted about going to the dealer every time that awful noise came back, and the dealer happily doing a $900 brake job every time and never mentioning "you know, you could make a couple stops in neutral and the noise would go away."

It may help to kind of break that fact check into pieces. The first part (EGR reduces emissions by lowering the peak combustion temps below where NOx is formed, and improves MPG by reducing pumping loss) isn't in doubt; those are the exact engineering reasons why the car has EGR.

Where the PriusChat theorizing comes in is with the later steps: (a) does Gen 3 have an excessive share of head gasket problems? (b) if it does, is there some connection between those and clogged EGR? (c) if it does and there is a connection, is "higher loaded temps" the explanation of the connection?

There seems to be pretty fair support for (a), that Gen 3s are having more head gasket problems than you'd expect. That's not just from owner posts about it on PriusChat (just about all problems are overrepresented in owner posts, because millions of owners who aren't having problems don't join PriusChat and don't post); it's also in posts by members whose shops are getting lots of Gen 3 head gasket work.

Step (b), some connection between the gasket failures and EGR clogging, seems to have some level of anecdotal support on PriusChat, though drawing conclusions about it is near-hopeless at this point because there are so many posts around saying it's so that any time a new member is having a misfiring issue of any kind, they read all the existing threads and then start a new one saying "OMG I have the head gasket because EGR right?!" and that promptly gets counted as new usable evidence.

Step (c), the idea that if Gen 3 has a head gasket issue and if it has some connection to EGR clogging, then the "higher loaded temps" are what is doing in the head gaskets, seems to be the most tenuous. Even if the connection is real, to find out whether this could even possibly be the explanation would pretty much have to start by finding out what temperatures harm head gaskets and what the temperatures are in cylinders with and without EGR, and whether they are close, overlapping, or not close at all. Even if it survives that step (which no one has done yet), it would still have to be compared with other candidate ways of explaining the same connection.

 

That’s about as expected with those miles. I think you’ll find the cooler/valve pretty socked-in, ditto for the small egr passages in intake manifold.

more info:

Bad Flywheel | PriusChat

 

Yeah as you say, not blocked. But maddening none the less, how that carbon shellac builds up.

Awaitin’ cooler/valve pics.

 

My EGR pipe and manifold looked similar but the EGR cooler was completely clogged. If you can, maybe point a flashlight into it and try to get a peek in there.