Two rocker arms off?!?! WTF?

So it's been awhile since I've been on here. Hope everyone in tundras.com land is doing well.

This time my hiatus was not from the ban hammer (I learned my lesson) but rather due to some lingering issues that I've had with my truck. I had it into the dealership a couple of times over the last few months explaining my issues but of course each time they said they couldn't replicate them.

Long story short, late last week the truck went into limp mode with the CEL flashing and me unable to go over 35mph (maybe a blessing in disguise). The dealership wasn't far away so luckily I didn't get stranded.

They call me today and tell me that the code is for misfires in cylinders #1 and #3. They moved coils but misfires stayed put. Come to find out that the rocker arms had completely come off in #1 and #3. How does that happen? Hopefully it can be resolved but does anyone know what underlying issue might have caused this or what other damage it could have done to the motor?

NOTE: I'm not here to bash Toyota and I'll delete the thread if that's where this thread goes. The dealership is another story. I'm just trying to get my truck back to running how it was when I got it.

Thanks

 

That’s a bummer. Sounds very rare. I’d be wondering what other damage was done. See if you can get them to give you a lifetime powertrain warranty or extend it at least.

 

my wife had an gmc acadia that suffered misfire issues. it allowed super rich exhaust to hit the catalytic converters, which caused them to fail. another $1,000+ repair. so look out for that.

 

also, unless they can pinpoint an exact cause on why the arms came off in #1 and #3, then I would assume the others are waiting to fall off as well. they should replace them all.

 

Need candid snaps of the affected valve train components.

I realize it's a lot like I'm asking for nudes but this is for science.

 

Never heard of this. In for whatever causations the dealer/mechanic may find on this.

 

Here is a cross-section view of the valve train. The rocker arms are not secured by any shaft but ride on the tips of the hydraulic valve lash compensators. There may be some scenarios where valve float could allow them to become dislodged (just guessing).

 

Collapsed lifter could leave enough slack for something wierd to happen?

 

Two at the same time troubles me.

 

Or seven. Probably relevant as it's a similar setup

https://www.youtube.com/watch?v=BLdMWkzSwXk

edit: didn't realize language in vid, loud at the end, don't watch at work yikes

 

Loose or damaged hardware is in the only explanation.

 

Really interested in what came off means. I had a rocker arm break on a mid life 88 trooper. When I pulled the engine apart, there was a tiny piece of electrical tape in the oil port. No way to tell when it got there, but the bearing galled and the rocker arm broke. I'm not familiar enough with the Toyota engine to know how the rocker arms are attached, but coming off doesn't sound possible to me.

 

Someone PLEASE tell me this came to some sort of resolution.

I am likely having the exact same issue, except I believe I've lost SIX rockers.

I posted my story here looking for help: https://www.tundratalk.net/threads/...repaired-still-misfiring.766557/#post-9474411 but the short version is I had bad misfires on 1, 2, 3, 5, 6 and 7 and found that some mice chewed two wires under my fuse block. Repaired those and the misfires continued. Pulled the passenger side valve cover and found the rockers for the intake side of #2 and #6 just sitting there. Haven't pulled the other side (because it's much harder to get off), but I assume it'll be the same on all four cylinders over there.

I filed an insurance claim (have comprehensive that covers rodent damage), but they only want to cover the wire repairs ($500) because they don't see the link between the wiring and the rockers. To be honest, either do it, but I don't believe in coincidences like this.

Didn't we all buy Toyotas so we didn't have to deal with this BS??

 

Wow.

 

HALLLPP

 

Did the truck run fine and all of a sudden you get misfire codes?

The only thing I can come up with is collapsed lash adjusters but that's pretty weak. The followers aren't really held by anything except the valve pushing up on them and being trapped by the cam lobe and the lash adjuster.

 

I suppose if you had a sticky valve that would let the follower jump out.

 

Yeah, always ran great. I bought it at about 90k, and did synthetic oil changes every ~4k for the 4 years I've owned it. It's now at 115k.

It does sit a fair bit because I'm usually on my motorcycles, but typically not more than 4-5 days at a time.

I'm trying to think through all possible outcomes. The worst one is that I can't get insurance to cover this, and I can't find a TSB or defect that will make Toyota deal with it. In that case, do you think I'd be committing truck suicide by compressing the springs and putting new rockers back in? Realistically I'd drive it straight to a used car lot and sell it at that point.

 

Totally agree. How do I go from running well to six stuck valves?

 

Put the followers back in and bump the engine without it starting and observe.

 

@empty_lord you ever seen this?

 

Yeah, that's probably the best course of action if I can't get someone to pay to fix this.

 

Well this is a rare one. Out of all the cars we have come through with issues only one car (a corolla) has ever spit rockers. That one was from over revving the engine


In extremely rare cases I could see a lifter leaking down over a decent amount of time and possibly allowing enough room for it to shoot out.. but even that seems hard to do. Freak accident is all I can think of honestly. Any weird tapping before this happened?

 

Can you tell if the lash caps are still on the valve stems? And what color is the gasket material on the cam housing, black would indicate someone has done a cam tower reseal

 

Only way you’ll get those rockers back in is taking the cams out.
I’ve had the rockers fall off when I was putting cam towers back on. There is no way you’ll get those suckers in without the cam out

 

I can't remember if the caps were still on the stems, and can't see it in any of my photos. Same with gasket material, but I can see some green in some photos; that the right color?

Thanks for the insights. So you don't think it's possible to get them back in with the cams in place? I was watching the video of that Corolla kid who spit 7 valves and I think he compressed the springs and slid them back in.

 

Lifters are hydraulic yes? Maybe a sudden loss do oil pressure across the board?

 

You could try, but the spring force is pretty damn tough. I’ve never had luck. The green on the cams? Looks like marker markings. I don’t usually see those in the engine. Yellow is typically from the factory. Lash caps are easy to look for. Just se if the top of the valve has a thing that comes off.

 

Still pretty rare, I’ve got guys that don’t prime the rockers before putting engines back together and they’ve never spit.
(Just made horrible ticking noises) only time I’ve ever seen one spit out was the mentioned corolla that the guy shifted from 2nd to 1st instead of 3rd

 

I’m just spitballing. If the cams didn’t jump around it’s the only thing I can think off off the top of my head. Certainly it didn’t over rev as it’s an automatic but maybe he was at high RPM and something blocked oil flow momentarily? Not probable but plausible.