New Head Gasket!

That's great! I hope you get at least another 172,000 on it!

 

Your hg want at 130k? I'm in Lakeland. What part of FL?

 

does anyone has the torque specs for the top engine cover? I could not find them in the manual

 

Very minor, 7 foot/pounds.

 

Hello
anyone here is willing to share complete repair manual for this job? Thanks.

 

I used the search function and YouTube

 

Pretty sure there's no 'complete repair manual' resident on this forum. You just have to look around and try to piece things together.

Searching on YouTube can be very fruitful, altho you're also likely to get poorly produced vids or ignorant vids. YMMV.

One way I've found to get productive searches done is to Google (not PriusChat search) something like: '2010 Prius replace head gasket', or '2010 Prius head gasket' (I have a 2010 Prius; you might substitute '2012 Prius'). What you'll get is nice bunches of related threads on PriusChat in your Google result, and you can look through those. Along the way, you should find a link to a video of two experienced guys replacing a 2010 Prius head gasket (it's on YouTube, of course). They move along at a blistering pace, but they know what they are doing.

PriusChat search might also be useful, but I really liked the above method.

I got LOTS of Prius info, of all sorts, not just head gasket related, using it.

EDIT: BTW, the title of that HG video: Toyota Prius 2ZR head gasket replacement (complete step by step). Be sure to look at the video description for info on tools required for the job.

 

Read this Entire Tread:
Just Bought a 2012 For $700 with a Blown Head Gasket | PriusChat

It should answer a lot of your questions

 

I'm not sure I buy their explanation, think the EGR clogging plays a big part. I've commented on this, on their YouTube location. See they've responded, and I've just replied.

I like their videos, think they're invaluable, but their explanations are maybe too pat.

 

Thanks. Just finished job, put everything back together, started car in maintenance mode. It runs rough and stalls with code P3190. Which has to do something with fuel.

 

Dirty Injectors?

 

What was it you did exactly?

 

I did head gasket change. Injectors were really gunky. I used break cleaner to clean them. I also cleaned intake manifold and throttle body at the same time. I guess next thing I’ll try is cleaning fuel system. Car hasn’t been started for at least 3 month until today after I finished HG change.

 

Maybe an intake manifold gasket leaking? Did you change all IM gaskets? If not, doing so is maybe $50 and relatively easy.

 

I bought gasket kit from Toyota that someone recommended here on priuschat for this job. I didn’t use all of them, but I did replace intake manifold for sure.

 

What kind of head bolts stretch more?

 

If you are referring to the issue discussed in the video above ...

Titanium bolts would have about half the stiffness (modulus of elasticity, Young's modulus, etc.) as the same sized steel bolts, with similar strength. Titanium has other issues being screwed into an aluminum block. But I believe in some applications, such as race motorcycle engines where engine teardown may be a common thing, they are sometimes used. Higher maintenance.

If you stick with steel, the stiffness does not vary much, even across different alloys and heat treating.

So what they (engine designers) typically do to make the head bolts more compliant is simple - they use thinner bolts. Obviously those will stretch more. An M10 bolt is thinner than an M12, with about 44/144 less surface area and proportionally less stiffness.

To get the strength they still need, with that extra compliance, they use very strong bolts to begin with - e.g., Class 12.9. And then they are plastically deformed when installing = torque to yield, TTY. The work hardening that occurs during the TTY process makes them even stronger. It has to be done carefully, but when it is, you have strong bolts that are also compliant. So that's the main reason why high grade / class, TTY, steel bolts are typically used for head bolts. The TTY process also leads to more uniform clamping force across the head, which is another reason.

And if that's not what you were asking, hopefully it's helpful to someone else.

 

Can someone tell me the purpose of disconnecting the battery; batteries? In the old days, cars had an alternator and starter, which had live wires going to each. A Prius doesn’t have that. I did the head gasket and did not disconnect either battery. It was funny to hear the solar running the hvac fan, however, all the work I did had no affect on anything. After thoroughly cleaning the tops of the cylinders and reseating the valves. I went from 50 to 55 mpg at 192000 miles.

 

Soyou can do electrical work related on the car or clear memory stuff, and not get a electrocuted by the high voltage.