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#1
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possible causes of misfire
1999 3.3L Grand Voyager Flex fuel model, running on gasoline.
It's getting fuel, the injectors are injecting, the spark plugs are sparking. When I run the engine enough to heat up the exhaust manifolds, #6 gets hot enough to burn me, but the manifold is not hot at 2 and 4. My conclusion is that these cylinders are not working, or not working optimally. The engine doesn't run well enough to idle, and the unburned gasoline comes out as black smoke. I acquired this van from a tow lot after somebody drove it for about 10,000 miles without an oil change. I make this guess because it used to belong to a friend who maintained it well, but it had 10k on the odometer that was put on after he sold it. And it has ugly oil. The engine produces a mild clattering noise like a stuck valve lifter(s). It doesn't sound like a bad crank bearing. Is it possible that the valves are stuck enough to not operate, rendering these cylinders inoperable? What other factors could be causing this problem? I've analyzed and fixed the fuel and ignition systems, and I'm 99% sure they're working great. All that's left is the possibility that there is something wrong mechanically. If it were a cam timing problem I wouldn't have some good cylinders and some bad, so it must be something local to one or two cylinders. Any ideas? |
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#2
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possible causes of misfire
"Robert Reynolds" > wrote in message ... > 1999 3.3L Grand Voyager Flex fuel model, running on gasoline. > > It's getting fuel, the injectors are injecting, the spark plugs are > sparking. > > When I run the engine enough to heat up the exhaust manifolds, #6 gets > hot enough to burn me, but the manifold is not hot at 2 and 4. My > conclusion is that these cylinders are not working, or not working > optimally. The engine doesn't run well enough to idle, and the unburned > gasoline comes out as black smoke. > > I acquired this van from a tow lot after somebody drove it for about > 10,000 miles without an oil change. I make this guess because it used > to belong to a friend who maintained it well, but it had 10k on the > odometer that was put on after he sold it. And it has ugly oil. > > The engine produces a mild clattering noise like a stuck valve > lifter(s). It doesn't sound like a bad crank bearing. > > Is it possible that the valves are stuck enough to not operate, > rendering these cylinders inoperable? What other factors could be > causing this problem? I've analyzed and fixed the fuel and ignition > systems, and I'm 99% sure they're working great. All that's left is the > possibility that there is something wrong mechanically. If it were a > cam timing problem I wouldn't have some good cylinders and some bad, so > it must be something local to one or two cylinders. Any ideas? What is the code in the memory of the engine controller? If it is running that bad the check engine lite should be on. Glenn Beasley Chrysler Tech |
#3
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possible causes of misfire
On Mon, 28 May 2007 17:08:42 -0600, Robert Reynolds >
wrote: >1999 3.3L Grand Voyager Flex fuel model, running on gasoline. > >It's getting fuel, the injectors are injecting, the spark plugs are >sparking. > >When I run the engine enough to heat up the exhaust manifolds, #6 gets >hot enough to burn me, but the manifold is not hot at 2 and 4. My >conclusion is that these cylinders are not working, or not working >optimally. The engine doesn't run well enough to idle, and the unburned >gasoline comes out as black smoke. > >I acquired this van from a tow lot after somebody drove it for about >10,000 miles without an oil change. I make this guess because it used >to belong to a friend who maintained it well, but it had 10k on the >odometer that was put on after he sold it. And it has ugly oil. > >The engine produces a mild clattering noise like a stuck valve >lifter(s). It doesn't sound like a bad crank bearing. > >Is it possible that the valves are stuck enough to not operate, >rendering these cylinders inoperable? What other factors could be >causing this problem? I've analyzed and fixed the fuel and ignition >systems, and I'm 99% sure they're working great. All that's left is the >possibility that there is something wrong mechanically. If it were a >cam timing problem I wouldn't have some good cylinders and some bad, so >it must be something local to one or two cylinders. Any ideas? Have you checked compression? What steps did you take to "analyze" the fuel and ignition systems? |
#4
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Update: mystery solved
"Robert Reynolds" > wrote in message ... >I finally decided to pull a valve cover so I could see what the hell was >going on in there, because nothing makes sense on this van. What I found >was a ton of oil crud caked on everything, a stuck valve, and a rocker with >a hole neatly punched in it by the valve stem. > > I'm weighing my options. I could replace the whole engine and be done > with it. Or I could send the head to a shop and put it back together, but > I don't know if the stress on the valve damaged the lower end of the > linkage. Not only that but the engine is full of crud. You may have a cam lobe messed up too. Need to figure that out before having the head reworked, because you'd have to pull the engine to replace that. |
#5
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Update: mystery solved
I finally decided to pull a valve cover so I could see what the hell was
going on in there, because nothing makes sense on this van. What I found was a ton of oil crud caked on everything, a stuck valve, and a rocker with a hole neatly punched in it by the valve stem. I'm weighing my options. I could replace the whole engine and be done with it. Or I could send the head to a shop and put it back together, but I don't know if the stress on the valve damaged the lower end of the linkage. Not only that but the engine is full of crud. |
#6
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Update: mystery solved
In article >,
Robert Reynolds > wrote: > I finally decided to pull a valve cover so I could see what the hell was > going on in there, because nothing makes sense on this van. What I > found was a ton of oil crud caked on everything, a stuck valve, and a > rocker with a hole neatly punched in it by the valve stem. > > I'm weighing my options. I could replace the whole engine and be done > with it. Or I could send the head to a shop and put it back together, > but I don't know if the stress on the valve damaged the lower end of the > linkage. Not only that but the engine is full of crud. Sounds like an engine which didn't see an oil change, just oil added, for a LONG TIME. I wouldn't waste a nickel on such a miss treated engine. |
#7
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Update: mystery solved
who wrote:
> In article >, > Robert Reynolds > wrote: > >> I finally decided to pull a valve cover so I could see what the hell was >> going on in there, because nothing makes sense on this van. What I >> found was a ton of oil crud caked on everything, a stuck valve, and a >> rocker with a hole neatly punched in it by the valve stem. >> >> I'm weighing my options. I could replace the whole engine and be done >> with it. Or I could send the head to a shop and put it back together, >> but I don't know if the stress on the valve damaged the lower end of the >> linkage. Not only that but the engine is full of crud. > > Sounds like an engine which didn't see an oil change, just oil added, > for a LONG TIME. > I wouldn't waste a nickel on such a miss treated engine. I'm thinking the same thing. My friend has said a few times that he changed the oil regularly, but maybe he's just trying to save himself embarrassment by passing the blame along to the idiot he sold it to, and I know that guy was an idiot based on other evidence. One way or another, there's a LOT of crap in the engine. I'm in kind of a bind about what to do with it, though. I know this sounds stupid, but I'm toying with the idea of installing a junkyard head. I understand that there are pros and cons, but it just might be worth it. I figure the engine is a write-off as is, so there's no risk of hurting the rest of the engine by trying. On the other hand, I could spend a fortune for a new or rebuilt engine, or I could spend a lot less but still a significant sum for a well chosen used unit and pay somebody with a shop to do the R&R. The low price alternative (without selling the van for next to nothing) would be to pay $69 for a head from the Pick N Pull, plus a gasket set, and see what happens. The 3.3 is an amazing engine that will stand up to abuse. I'll bet I would get a couple hundred bucks worth of use out of it, and probably more. Naturally, I would also make the commitment to 1500 mile oil changes for a year or so, just to make sure. |
#8
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Update: mystery solved
last one i seen like that with the hole punched thru it needed a cam too
Robert Reynolds wrote: > I finally decided to pull a valve cover so I could see what the hell was > going on in there, because nothing makes sense on this van. What I > found was a ton of oil crud caked on everything, a stuck valve, and a > rocker with a hole neatly punched in it by the valve stem. > > I'm weighing my options. I could replace the whole engine and be done > with it. Or I could send the head to a shop and put it back together, > but I don't know if the stress on the valve damaged the lower end of the > linkage. Not only that but the engine is full of crud. |
#9
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Update: mystery solved
philthy wrote:
> last one i seen like that with the hole punched thru it needed a cam too You've seen this before? I thought it was really freakish. How often does this happen? |
#10
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Update: mystery solved
i have seen it twice in the last year
Robert Reynolds wrote: > philthy wrote: > > last one i seen like that with the hole punched thru it needed a cam too > > You've seen this before? I thought it was really freakish. How often > does this happen? |
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