2011 Prius Head Gasket Failure

I'm not sure I follow. Isn't that piping something like 12 mm diameter? When not occluded, with intake manifold vacuum at one end and exhaust manifold pressure at the other, and the valve wide open (tiny? looks like it has a bore comparable to the pipe), the flow volume could be pretty respectable.

And the ECU really does have to control that valve according to rpm and load; opening it even a small fraction of the way is enough to asphyxiate the engine at idle.

 

There were several previous comments that maybe high speed driving, hill climbs, or whatever could "blow the carbon out". I'm thinking the rate of flow is way too low for that.

 

True statement. Bill Norton say otherwise

 

Prius engine runs at low manifold vacuum (high MAP) most of the time, unlike most.

 

If running a Prius WOT will burn off the carbon, my EGR system should have looked like polished chrome.

 

Bill the science guy would say the carburetor needs tuning.

Pixel XL ?

 

Plus, to be super pedantic, the EGR valve closes when the demand is high, so WOT might clean something but it won't be the EGR path. ( And I tested this today going up a steep hill while watching Torque dials: when the HSI pushed to the top end of red, EGR step dropped from 60-ish to 0. Wikipedia got something right! )

 

Not only directed at Avi, as everyone is welcome to comment.

Do you have a preference on Head Sets (Toyota, Beck Arnley, Fel-Pro, etc) -- are any actually better and why?

Knowing that Federal-Mogul owns Beck Arnley and Fel-Pro (Hybrid 911 claims to use Fel-Pro head sets), is the overall quality the same for either? It looks like both come with or are missing extra gaskets or pieces parts.

Here is the $89 Beck Arnley head set at RA : https://www.rockauto.com/en/moreinfo.php?pk=8383384

Here is the $114 Fel-Pro head set at RA : https://www.rockauto.com/en/moreinfo.php?pk=6787428

Here is an $69 ebay head set that includes head bolts and a single tube of RTV : Head Gasket Bolts Set Fit 10-13 Lexus CT200H Toyota Prius 1.8 2ZRFXE | eBay

Another ebay listing that appears to be the same as above, and also doesn't include the timing tensioner gasket, the pictured parts sheet makes mention of the Federal-Mogul website, though unsure if this set is FM : Fits 10-15 Toyota Prius V Lexus CT200h 1.8L Hybrid Head Gasket Set Bolts 2ZRFXE | eBay

 

The FelPro head gasket set that I used when reinstalling my Gen 3/4 engine had a head gasket that looked like the OE gasket. I can’t prove that it was a Toyota part in the box, but most of the FelPro head gaskets stocked in my store are blue, not the black color the OE one and the one I installed were. Is it possible that one bought the gasket from the other, yes. But there is really no way to prove who bought from whom.

 

Is Toyota the only one that makes a full gasket kit, that one that's got the head gasket plus most other rubber gaskets, O-rings, valve guides and so on?

It's indicated as this p/n:

04111-37315

in the attached TSB.

 

So I replaced HG, put everything together, car is idling rough. Turned out I skipped chain one tooth on crank shaft. So I took cover off, put chain where it supposed to be, still idling rough with P0301 code. I did compression test, cylinder 1 has 0 compression, others around 90psi. Took everything apart again, now I found intake valves on cyl1 were not closed all the way. My question is: could 1 tooth off timing chain cause valves to bend?

 

Yes, now that you started it and had it running. This was discussed in another thread.
I don't remember where it's at though, sorry.
ALWAYS rotate the engine by hand 720 degrees and check the timing marks.
If you can't turn it over by hand, then the timing is off.

If you think about it, you probably heard a loud "clank" when(if) the piston hit the valve.
Since you have it apart, you can replace the valves, seat them in, then make SURE you get
the timing marks correct.

Then rotate the crank 720 degrees and the marks should be lined up.

 

My suspicion is that on assembly of the cam bridge to the head, the cams were not located properly. As the bridge bolts were tightened down, the number one valves opened. This caused the bend to the valves. The manual says to lock the cams before the bridge is removed and unlock them only after the chain is on and tensioner applying tension. One tooth one way or the other is not far enough out of time to bend valves.

 

2 intake valves on cyl 1 were bent. Good thing they are not too expensive. After replacing them engine runs smooth. I still get little bit of shaking/vibrating at 1500rpm. Will take intake manifold out and clean very good with some kind of degreaser. See if that helps.

The Critic: I did not take head to machine shop. The head seamed to be in good shape.

 

Thanks for the follow up!

 

Another true statement:
The OP had to do all this work replacing the HG after doing all the Right Stuff, according the the forum Gurus.

Could it be- Toyota just has a weak link with this engine design?
Could it be- that the Gen 4's are NOT looking much better as to how long a Prius can go before the HG goes bad,,,
like clock work.

All cars eventually have an engine failure at some high mileage point.
With the Prius engine it is the Head Gasket.

I'm glad only 1 of my 3 cars has a head gasket. It's a +240k mile Honda.

 

I witnessed rather big black cloud coming out 2010 Prius tailpipe when being floored at highway speeds. We were driving car home after purchase and had to drive hundreds of kilometers with just short breaks when it happened. I was in another car following Prius and after some 400km driving my son started overtaking a truck - and with Prius one obviusly put the pedal to metal- and then PUFF happened. From what i understood about previous owner, she apparently had been doing lot of city driving. At that time odometer was at 210kkm (about 130kmiles). Going to egr+cooler+im cleaning within few days. MPG around 45. Hope to get better

 

That's good.

First link in my signature has info.

Additional tip: the EGR cooler has a hard-to-reach nut on the underside. You can remove this in advance, without disturbing anything else. It's a good strategy to get that off first. My 2 cents, don't bother putting it back on. Ever. I've also (permanently) removed the stud that nut screws onto. Might make it easier extricating the cooler. You'll need an E8 Torx socket for that.