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?

Reply to
Robert Reynolds
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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

Reply to
maxpower

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

Reply to
bllsht

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.

Reply to
Joe

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.

Reply to
Robert Reynolds

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.

Reply to
who

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.

Reply to
Robert Reynolds

Reply to
philthy

You've seen this before? I thought it was really freakish. How often does this happen?

Reply to
Robert Reynolds

Reply to
philthy

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

Reply to
Robert Reynolds

Reply to
philthy

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.

Reply to
Robert Reynolds

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

Reply to
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.

Reply to
Robert Reynolds

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