Multiple misfire after fill up - coincidence?

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bobmbx

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I never do go by blind faith :D
The tech did a compression test and had reverse compression. I think he's probably right in his assessment that the valves are stuck closed.

I thought about pulling the valve cover to take a peek at what is going on before I make a final decision. Considering how cheap I can get a temporary replacement vehicle, I'm even considering letting the vehicle sit for a while until I can spend some time/money on it and just do a motor swap. Considering I drove it home when the problem first manifest itself and the amount I ran it while trying to troubleshoot, do you think another few miles will hurt it any more than it already is? Seems like the damage has been done at this point

Are the valves open or closed? Earlier you posted they were open, which is the worst case (possibly contacting the piston...new engine time if so). If closed, you have more options. The valve cover needs to come off first. If its just the cam followers, thats easy. The cam could be damaged, and that would be a bit more involved.

What worries me is why did they both fail at what seems to be the same time.

Edit: I re-read your verdict post. We don't know the position of the valves yet.
 
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Trainmaster

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Yep, pull the valve cover. Half hour's job. May not be a big deal. Would I drive it? I'd rather not, because I could do more harm. But you could take a chance?
 

1955moose

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Could have been an oiling problem that was ready to rear it's ugly head. If this was one of those lazy oil change vehicles, it's possible.The fuel fill up was just a coincidence..Usually the stuck lifter happens farther back like #3 or #4, or #7 or #8. But until a tear down of the top half, we won't know. Got to get a little dirty!

Sent from my N9131 using Tapatalk
 
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Matticus

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Negative compression, so stuck closed. I didn't originally post whether they where open or closed, just asked about the ramification of one or the other. I originally just got a call from someone at the front desk relating the basic info. I didn't talk to the tech and find out the deets until later
 

TobyU

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Negative compression which means the needle goes up and sucks back down means the INTAKE is not opening. Doesn't mean it's stuck. I bought a 4.6 that was this way. Pull that valve cover now!
Mine was 20.00 fix and could have been free fix. One intake rocker popped out from under cam. I replaced it and lifter anyway but they looked perfect.
You probably won't need to even pull head to fix so it's easy and cheap.

Edit: The big question is what caused this. She turned it off and filled it up with gas and instantly on restart it ran rough??
Too coincidental not to be from filling up.
Does she fill it really full?
Could it be that it was really filled full and the evap got liquid into it and into intake and cylinders. Enough to almost hydrolock and when a fuel wet cylinder's piston came up and fuel couldn't ignite and misfires a plenty and valves being urged to close even they aren't ready... Could upset things enough to rattle rocker or of there.
I'm grasping here but pull the valve cover and see.
 
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Matticus

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Doesn't that meet the definition of "stuck"? I plan on putting the valve cover this weekend. I keep hoping that it's something incredibly simple and cheap like you described. I shall report my findings
 

TobyU

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Stuck is usually used when a valve is tight or seized in its valve guide. They can stick open, closed, or anywhere in between.
Physically unable to open or be opened or moved.
Not opening can be a perfectly fine valve, guide, seat, and pushrod (for ones with those) but it lifter/lash adjuster or rocker is messed up or missing because it's laying in head like mine was, the valve won't open but not actually stuck. You could push the spring down with hand and they'd move and spring back closed.
 
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Matticus

Matticus

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Edit: The big question is what caused this. She turned it off and filled it up with gas and instantly on restart it ran rough??
Too coincidental not to be from filling up.
Does she fill it really full?
Could it be that it was really filled full and the evap got liquid into it and into intake and cylinders. Enough to almost hydrolock and when a fuel wet cylinder's piston came up and fuel couldn't ignite and misfires a plenty and valves being urged to close even they aren't ready... Could upset things enough to rattle rocker or of there.
I'm grasping here but pull the valve cover and see.

This was going to be my follow up question. I'm so hoping it's something as minor as a roller follower, but if it is, what caused it in the first place? I watched this video a little while ago - are these something you are supposed to replace at a certain interval on these engines?

My wife just fills it up until the pump stops as far as I know. Doesn't do any extreme topping off like I occasionally see people do.
 

jeff kushner

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I would look before doing anything else but Rislone can free stuck valves but at 242K, you're ahead of the game, even after doing the other stuff mentioned. It sure isn't work 5K to ANYONE else. It's simple math at this point, unless there are reasons to keep.

good luck,

jeff
 

TobyU

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It's hard to tell what caused it even if you do find out exactly what it is. These roller rocker followers are not known to have to be replaced and have gone 300,000 miles plus and look as good as new. Others that had the bearing fail and get extreme play and wobble and fall off at under a hundred thousand.
The only cost effective way to replace an engine in a vehicle such as this is to get a good used one from a salvage yard. You'd be surprised what good prices are out there. A friend of mine just last week body 4.6 for a town car with 83,000 miles from a salvage yard for $505.
If you just have a top-end or timing chain issue and can do the work yourself you can pull the heads or pull the engine do then pull the heads and repair and keep it cost-effective also.
The thought of replacing an engine with a new one or a remanufactured one or having somebody rebuild your old one just turns the situation into an upside-down waste of time and money. In most every case you could sell what you have for whatever it's worth with the problems it has, put the money with it you would be going to put into into the repair then go shopping and take your choice of many vehicles in that price range.
I don't know why but it seems the majority of people have an unusual attraction for the vehicle they havd had for a while and feel better about getting it repaired or replaced then going and buying another one.
I have always been just the opposite. Normal daily drivers and basic vehicles are just pieces of equipment or back and forth to work. They're not my pride and joy that I'm collecting and plan on keeping forever and want to keep perfect. I'm more than happy to cut my losses and get rid of one and replace it with something else that's probably cleaner and nicer.
 
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