Suddenly getting misfires on all four cylinders

Oh, it is completely different. I had the whole engine shimmy and shake routine when my head gasket went south (17K ago), so I'm *very* familiar with that. I may make a mistake on whether or not the motor is actually running (happily corrected on that), and I'll never concretely claim that the head gasket couldn't still be a problem (original misfire issue that started this thread), but I *can* concretely say that the current behavior on startup is nothing like what I had with the bad head gasket.

So.... I can buy the fuel concern. I can pull the fuel line and see if it fills a can (or whatever). But.... it seems like even a fuel starvation problem wouldn't cause the P0011 error or that knocking that is evident on the video. That knocking/pinging is something I've never heard before on this car.

Actually.... I think I can command the fuel pump to turn on and then look at the fuel pressure all via OBD. If so, will that suffice to feel confident that the fuel is not an issue?

 

Yeah, I'm very quickly coming to the conclusion that I'm going to have to bite the bullet and check the timing chain. Ugh. That is a moderate PITA, especially since I am pretty darned confident that it is fine UNLESS the whole damned chain has broken (hmmm... that would explain a P0011 too, I suppose).

My reasoning for why I'm pretty confident the timing chain has not jumped a cog:

1. Car has run fine for 15K miles after the head gasket, which is when the skip would have been introduced
2. Car still purred very nicely for the next 2.5K miles, it just threw misfire codes
3. 2K miles ago, or so, I changed the tensioner. The mechanic said he thought he heard slap but didn't see anything amiss when he removed the valve cover. The chain looked tight. I was *VERY* careful not to release tension on the crank so as to avoid a cog skip. The original tensioner looked fine, by the way, and the installation went very smoothly.
4. "Something" happened 30 feet ago (LOL) that was catastrophic. P0011, P0335, pinging/knocking as evidenced in the video, and an inability to start the engine. I wasn't in the car when "it" happened, but my daughter didn't notice anything amiss (but, hey, she is 26... she probably had the radio on!)

So, we went from running fine but with periodic misfire codes to not even being able to run. If the issue were the timing chain, I think it would. have had to skip two (or more) teeth at that intersection.

Pulling the valve cover isn't horrible. I can't see the crank index and chain, however, without pulling the harmonic dampener off. Even that isn't so hard except for the fact that Toyota makes you remove an inner wheel well cover. And to get to one of the screws for that, you need to take a bunch of other fasteners off. I thought that was kind of a dumb design, or one to increase service cost!

But, it looks like I really need to put a nail into the whole timing chain thing. Put simply, it is an unknown and I need to eliminate unknowns.

 

Leadfoot.... Awesome question and, unfortunately, something I didn't put into the initial info.... Because the variable cam gear works off oil pressure, that is one of the first things I checked. Oil level is fine. I also did the last oil change, so I know the viscosity is correct too. I don't know about pressure; I don't know of a way to determine it, and if it requires that the engine be running, well, I'm cooked for the time being!

But... On the line of oil... I have been wondering about the oil control solenoid. If that were on the fritz, that would certainly cause the gear to not advance. But, then again, I think we already covered this in a different post. Someone (you?) said that most modern cars will throw a different code in the event the cam does not follow the commanded position (which would be the case with a malfunctioning solenoid).

Regarding machining.... I bought this car new, so I can at least say that the head has only been machined/decked once, if that helps

HV power level.... I just checked the car. Darn. It is down to 1 bar. I may have to move the HV pack to the other car just to charge it. This sounds like a PITA, but I don't want to damage the battery and I still have no real idea on what is going on with the car.

 

The actuator is super easily accessed as it is on the top of the valve cover. I pulled it just to see if there was crud in there that would preclude movement. There was none and the spindle moved easily. I didn't check it with a 12 volt source, though. Maybe later...

So.... I think this will be my course of action:

1. pull the valve cover
2. pull the harmonic balancer
3. Verify that the witness marks line up to the appropriate links (I wonder how many turns that is going to take!
4. check for continuity between the ECU and the cam position sensor (guess I need to pull all power when removing the connector on the ECU?)
5. check for continuity between the ECU and the crank position sensor
6. check for continuity between the ECU and the cam actuator solenoid
7. Check the filter screen for the VTC (will require removing the left bearing bar (non-scientific name)
8. Check the actuator movement by apply 12VDC to the pins
9. Put everything back together
10. Disconnect the fuel rail and see if the pump is pumping gas (or, can I just see the pressure via OBD and assume that is good? Will the pump come on when only in ACC mode? I don't want to try to start the car because I want to preserve my HV battery)
11. Maybe steal the fuel rail and injectors from the working Prius V?
12. try to start
13. If I still can't start, I'm going to need to yank the battery temporarily so I can put it in the other Prius to charge... Not looking forward to that.... I'm *really* hoping I can solve this before I need to go down that route

Does this sound like a viable plan? Any suggestions, deletions, additions, etc?

 

Yep, it definitely isn't good. Although it could also be an inexpensive fix too. Frankly having a hole through the side of the block would be a bummer, but at least I'd have a strong idea that if I got a new engine, things would work. Right now, I very much expect that a new engine would have the same problem... I do, after all, have to put the old solenoids, ECU, etc onto the new engine.

I'm willing to buy a cheapo oil actuator valve for purely testing purposes. If the car suddenly behaves, I'll buy an OEM part for long term, but I suspect I'll find it isn't a valve. If there is a problem in that area, I'm think that the gear might be more suspect. Sadly, I can't think of a way how to test that though.

 

At this point, I think the general tenor here on this thread is that the noise I'm getting (see video) is not consistent with a "simple" issue with the advance retard system. Although I very much want it to be a solenoid, or similar, it seems like each time I try that, I run into a brick wall. Sadly, I just don't know what an engine sounds if the variable cam hydraulics were, for instance, not charged with any oil. Would it ping/knock the way mine does? Is the current sound the engine makes *only* something I would hear if there were some dire mechanical issue (bent connecting rod, broken valve(s), whatever) or is it just a normal sound when there is a problem with the whole variable timing stuff? And, of course, there is the ongoing question of whether or not this would cause a P0011 error. That is one thing that remains consistent in my engine. It throws the P0011 almost immediately (P0335 seems to have disappeared for now).

I've got the cheapo VTC solenoid coming as a diagnostic tool, but given that everything else I've tried in this vein of thought has netted no positives, I'm not giving it a lot of hope.... All I can say is this. I'm a stubborn old cuss. Even if I put a new engine in this thing, I am going to take the old one apart. I really want to find out what the issue is.

 

OK, that is relieving to hear. I'll still be pulling the valve cover off for a look see, but this is the first time I've heard an opinion about the sound coming from the engine during cranking (apparently *not* starting, which was a mistake I made...)

So, may I ask where you think the noise would be coming from then? In a fully retarded position, my assumption is that the valves would still not contact the pistons. To me, that is what I think of when I hear the sound, but hitting the pistons would be a bad thing. I would have imagined Toyota engineers would have avoided that scenario in all cases. Actuators break, oil levels go down, etc, and all of those would result in an inability to move the VVT gear.

When you say "I wouldn't expect it to make extra noises"... just to be absolutely clear, you do NOT hear extra noises here, right? The pinging would be 'normal' in my interpretation of your comments. The pop (halfway) would not, but that was a onetime thing that I'm personally attributing to a backfire due to way too much unburnt fuel.

hmm, and there still is the P0011 DTC. If there is a separate code for 'commanded not being attained' versus 'no rotation', it would seem as though the only possibilities would be: a bad ECM, bad wiring, or a broken chain. I would think a bad actuator or gear would result in a P0012, not P0011

 

I have more information, and it is a doosey.... I took the valve cover off and WTH! Three of the rocker arms are sitting on the bottom of the valve area. While I was fishing one of them out, another fell off. I'm *completely* baffled by this, but clearly it is a problem. The cam is its proper position and the chain looks fine (haven't checked whether or not it jumped). It doesn't have any slop at all. So, in addition to the obvious question of the rocker arms, there is the other question of "why the P0011 error if the cam is turning".

But that is secondary, I suppose. The huge question is why are the rockers off? And, how can they even *come* off. I would think that they are always at least under *some* tension or a jostle of the car could dislodge them. And, perhaps, the backfire pushed them (or some of them) off?

The next question is... what is next? I'm assuming the noises I heard were the rockers rattling around? I don't actually see any damage in there, but I have to ask... Is it possible for there *not* to be damage? And if there is damage, is it not worth trying to fix this?

Oddly, I'm not especially angry. I'm well beyond that. I am more interested in what happened, how the rockers got dislodged, what damage is/could be there, is it worth repairing, how do I prevent whatever happened from happening again.

 

I think the thing that bothers me is that I can put the rockers *back* in place without a lot of effort (or remove others). Yet, I don't see the cam being high or anything. How can that be? The exhaust side has slight tension on the rockers to that they cannot move.

I was technically in there about 2000 miles ago when I was replacing the chain tensioner. Now, I will never say that I cannot make mistakes, but I seriously don't think I knocked anything. I am pretty careful. Further (and again) I don't know how this wouldn't be captive. I just feel like the scratch and sniff test isn't coming back rosy right now.

There is also the whole code thing... Why the P0011 DTC that seems to imply NO movement of the cam at all when I think there must have been some. Maybe the engine isn't turning at all when trying to start? I'm going down the path of perhaps a broken shaft? And, then, perhaps that muffled bang (halfway in the video) really was a backfire, and that caused the rockers to get dislodged? is that all plausible?