Re: Venture 2000, Engine light, Miss fire 6th cylinder

Jun 25, 2003 4 Replies
L

Drove the van some more, now the Engine light is on again. What could cause an oxygen leak?



I have a venture van 2000 and recently got an misfire code that was read at
> the mechanics shop. Also, scanner detected an O2 leek. The cleared the
> error message and (June 25th) I change the spark plug for that 6th cylinder.
> I notices the nipple circle on the top hook of the spark plug was totally
> gone. I checked a different plug and the nipple was fine on that one.
> Also to mention that we had problems starting the ignition on the first try
> (sometimes takes 5 tires). Now that I put a new spark plug it starts like
> a beauty. I had the engine light come up before (5 months ago) and
> mechanic found a O2 leak. But did not mention a miss fire problem. That
> time he cleared it and it was fine until a week ago. So now I want to
> figure out why I had this problem so it does not happen again. My
> warranty just ran out and will be selling the van this summer. I would
> appreciate any additional insight as to what the root cause of this problem.
> Could a miss fire cause O2 leak? Or did the o2 leak caused the miss
> fire, leading to worn out spark plug? I have about 50,000 km (about
> 30,000 miles). What do you think? Thanks.
>
>
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B

Don't know of any oxygen leak. You probably have a bad oxygen SENSOR which will need replacing. I just had to have mine replaced on 99 Venture at 33000 miles...

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T

To me it sounds like cylinder 6 is running lean. This would make for a very hot cylinder and could have melted off the electrodes from the spark plug. Possible causes: clogged injector, bad intake gasket (these engine are notorious for them), burnt valve. I would get this problem solved ASAP so you don't cause serious engine damage.

Which O2 sensor was showing the leak? You car does have more than one. IT has one before the converter and after. If it is the O2 before the converter check the exhaust gasket between the pipe and the manifold to make sure that it is not leaking. This will also cause a lean condition, and possibly a faulty O2 sensor reading.

Tim

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L

CONTINUATION: I asked the mechanic again what exactly did the scanner read. He said the left bank reading was lean. He also mentioned that cylinder 6 is miss firing (I assume that the left bank is cylinder 2,4, and 6). I replaced the 6th cylinder spark plug. And at first it seamed that starting the van was a lot easier. But next day engine light was back on and it takes about 5 tries before the ignition starts. Question can ignition problems have anything to with this lean reading. Can it be related to the miss firing problem? If so, If so difficulty starting especially in the mornings, does that give you a clue if it could have something to do with a bad sensor as opposed to miss firing problem? I would like to address the mostly likely problem first or the easiest solution first.

btw: I year ago I had sugar in the gas tank, so I had the tank replaced. And added some fuel injection cleaner in the gasoline. I have had no engine light

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G

Ahhh, a lean condition, that makes more sense than a "O2 leak". Left bank is 1,3,5. A misfire on six should cause a rich condition on right bank which the computer could misinterpret as lean on the left. After having it fixed the light came on again.....that doesn't mean the same trouble code is reset. Could be something else this time. An injector sticking can cause a lean condition. GW

lbbs wrote:

-- GW - note incorrect email address

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