[font="Times New Roman"]I have a 2000 C5 with 6 speed, and 80,000 miles. Up until yesterday, it ran perfectly. About a block from home, it started missing, and I could smell unburned gas fumes. Today I went to check where the leak is, and discovered that it is smoking white out the right side exhaust pipe, and that is where the gas smell is coming from. The check engine light is now on (probably due to the over rich mixture sensed by the O2 sensor), and there is no external gas leak to be found. I do not have a code reader, and do not want to drive it anywhere as it is. Any ideas what happened? Thanks in advance. Gumby...

 

Check engine light is probably a misfire code, and will tell you what cylinder is misfiring. White smoke is antifreeze, light blue smoke is oil. Do you smell antifreeze? White or blue is no good, white probably means head gasket, blue could either be valve guide or rings. Best way to tell is to pull spark plugs and look at them. Sorry for the bearer of bad news. []

 

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There is no smell of anti-freeze, just raw gasoline. Is there any way to extract fault codes without using a code reader? Is it possible for an injector to malfunction and dump so much gas into a cylinder, that it can not fire at all, and sends the gas out the exhaust as a white fog? I did not notice the smoke when the engine was warm, only when I started it up the next day. I will pull the plugs, and let you know what I find. Thanks for the reply. Gumby...

 

Really sounds like a head gasket is blown to me. Check your coolant in your resevoir and see if there's some oil residue in it...

 

Yes it is possible you could have a stuck injector. Also need to get a noid light on that cylinder that is misfiring to see if your injector pulse is messing with you. Noid lights can be purchased at most auto parts. Unplug the injector, plug in the light and start engine to see if light pulses or stays on all the time @idle.[8D]

 

It????? LOL Lee

 

It's not a too-mah... I pulled the right side spark plugs, and numbers 2 and 6 were still wet with gasoline to the point that I could have probably lit them with a match. Anti freeze is still full, and no oil floating in the reservoir. The oil also looks normal. No gray slime on the dipstick, so I think the head gasket is ok. It is just massively overfueling those 2 cylinders.
I found out how to display the fault codes on the dash, and there is only this one for the engine. 10 PCM P0300 H C (missfire, both historic and current) The only thing is, that it does not tell what cylinder is missing. Best guess is 2 and/or 6. I am familiar with the manifold design and layout of the older carb equipped Vettes, but not the newer injected stuff. I am hoping that someone can answer a couple questions for me.

1. Is there any way that the design of the manifold could allow a fuel leak inside it (like a blown injector o-ring) to flood both cylinders 2 and 6? The odds on 2 injectors failing in a full fuel mode at the same time, seem a bit thin.

2. Is there any way of testing the injectors with them still in the car, other than checking the coil resistance?

3. Is there anything special that I should know before pulling injectors out of this engine? I assume that I will need a set of o-rings to put them back in.

Thanks again, gumby...

 

P0300 is a random misfire code. You have either lost 2 coils or have injector probs on those cylinders. Need to first check and see if you have spark on those cylinders. I think you probably have spark probs since it hasn't set a rich code which would happen if you had injector probs. One way to check to see if they are pulsing is to get a long screwdriver a place it against the injector and against your ear on the other and listen to see if it is clicking. My money is on the coils. Good Luck [8D]

 

Life is all better now. Turned out to be the number 6 injector stuck wide open. I kept smelling gasoline while checking things out, and decided to rotate the engine to find out if the cylinders had gas in them. Good thing that I did, because no. 6 was full. I removed the fuel rails with the injectors still attached to them, turned them upside down, and turned the ignition switch to the "on" position without cranking the engine. Number 6 sprayed a stream of gas about 10 feet, and continued to spray after the key was turned off until the manifold pressure was gone. Aparently it would do that all the time that the key was on during testing. This must have put enough gas into the manifold that it ran into the runner for number 2, and caused that plug to be wet also.
I think that the reason that it did not set a rich code is because it was dumping so much gas into the cylinder, that it was going out the exhaust as a completely unburned fog. I wonder if I had put a sparkplug into the exhaust pipe, if it would have put out an F-16 style afterburner flame???? Probably just the sonic boom... Anyway, thanks for the advice. Gumby