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?

 

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

 

Have you checked compression? What steps did you take to "analyze" the
fuel and ignition systems?

 

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.

 

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.

 

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?

 

i have seen it twice in the last year

 

Do you suppose the valve was starved for oil because of gumming, and it
seized?

 

no more like the rocker arm was

 

The hole is punched in the side where the valve is, and the valve seems
to be stuck open now. The rocker has full motion when the engine is
cranked.

 

I had an engine that was like yours. I finally had Jiffy Lube do 3 oil
changes with some cleaning oil and new filters each time. Ran engine
aboput 20 minutes between changes. Did another 100K with the engine.
The cleaning oil sure did move out lots of crud. The oil pan drain was
clogged but good. They sprayed/squirted in lots of solvent to get all
the stuff out of the pan through the drain. I expect that transmission
fluid would do the same thing if you are into messy work. Jiffy Lube
charged me $75.00 for all their time and effort including the cleaning
oil. A bargain now and then.
Bob AZ

 

That's exactly the kind of thing I was thinking of doing, using either
ATF or one of those Super Engine Flush products from the parts store. I
had actually considered running it a couple hundred miles between
flushes, but I think your idea is better. Just get as much out as
possible all at once.

Given my current options of either fixing it or selling it, I figure
it's a good idea to gamble a couple hundred bucks on a used head and a
flush-out to see how much use I can get out of it.

Thanks for the anecdote.