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2004 Pontiac GTO
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167 Posts
Discussion Starter #1
I just purchsed a new 04 GTO A4 on Saturday...it had about 50 miles on it when I decided to give it my first full throttle test run...I turned the TC off, and mashed the throttle. It did not impress me or my friend from a launch standpoint, and then when it shifted to 2nd, all Hell broke loose - the engine stumbled, bucked, backfired and just about wouldn't run under any throttle load. I drove about 100 yards, pulled in to a parking lot and shut her down. Popped the hood, nothing looked out of the ordinary, so I started it again. Same terrible running engine, felt like one or more cylinders was not getting spark.

I had to get home, which was only about a mile, so I limped her along at about 15MPH, the engine bucking like a rodeo bull and backfiring out exhaust ...Then the engine light starts to flash...

I limp most of the way home, and all of a sudden, everything smooths out, the engine light goes out, and power seems to be restored. I drove the car another 1/2 mile or so with no trouble, but with a very easy right foot for fear of further trouble.

Now, in my fairly vast experience with GM cars, the engine was acting like one of the spark plug wires was shorting out or a coil was not firing...Nothing out of the oridinary, but a problem like that does not simply go away like nothing happened after running so bad just minutes before, and without even restarting the engine - :confused:

I am taking it back to the dealer Monday morning for service....Has anyone else experienced this or heard of a similar problem, especially with only 50 miles on a car?
 

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Been here for a long time...
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4,663 Posts
Flashing SES light is a misfire code. Definitely not normal. Maybe a coil pack not firing or loose plug wires?
 

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I like boobs.
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6,581 Posts
Note to new car buyers: Read your manual. Most will tell you to drive the car light for the first 1000 or so miles. The thing hasnt even had time to wear anything in yet, most importantly the rings and bearings. Now that doesnt mean you cant get on it here and there in that 1000 miles, but i'd put more than 50 miles on the thing before trying to lay down some rubber.

As for power, everyone knows once the engine breaks in for a few thousand miles it will pick up power. The break in process helps this. (Break in != full throttle everywhere you go.)
 

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CSiJason said:
Note to new car buyers: Read your manual. Most will tell you to drive the car light for the first 1000 or so miles. The thing hasnt even had time to wear anything in yet, most importantly the rings and bearings. Now that doesnt mean you cant get on it here and there in that 1000 miles, but i'd put more than 50 miles on the thing before trying to lay down some rubber.

As for power, everyone knows once the engine breaks in for a few thousand miles it will pick up power. The break in process helps this. (Break in != full throttle everywhere you go.)
As stated elsewhere on this board, brand new Corvettes are started on the line and driven over in a dyno room for checkout. With 0 miles on the car, they are run at full throttle.

Just because the car has no miles on it doesn't mean the engine doesn't. They are already run in before they are even put in a car.

You can go full throttle right from the get go if you wanted and no damage would occur. I wouldn't but you can if desired. I did the first full throttle pull in mine at 94 miles :)

These LS1's do make more power at more mileage though. Has nothing to do with break in as they all do it regardless of how it was driven in the early miles.
 

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2004 Pontiac GTO
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167 Posts
Discussion Starter #7
I dropped the GTO off at the dealer just a while ago...They have not had a GTO in for service with the same problem, so they are equally concerned...I will keep you Guys posted on the results.

As far as the "don't go full throttle before breaking it in", theory...I am very familiar with new cars & new engines. There is no real risk of damage when "using" an engine as it was designed, regardless of the miles/hours on the engine. Most race engines go from assembly to the Dyno with no "break in period".

And finally, what I encountered is most likely a computer/spark problem, not an engine problem. :)
 

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2004 Pontiac GTO
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167 Posts
Discussion Starter #8
The tech was able to duplicate the problem, so they are keeping it overnight - the guy says they got a code, but he didn't have it handy....Hope they can figure out what happened :-off the
 

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Captain Thread Killer returns
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good luck....that does suck
 

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I like boobs.
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Didnt mean to be so harsh earlier, but it doesnt shock me the engine had problems with so few miles on it.

I'm not suprised they stick Vettes on a dyno and run them through a break-in process, but that is a Vette, I doubt GTO's get the same attention.

My best guess is the bonehead porter was sent to fill the tank up when you bought the car and the nimrod probably put 87 octane in it which in a 10.X:1 compression car, that spells trouble. Even with knock retard it may not have responded fast enough or great enough to back timing out to save the engine from severe detonation. This is my most logical thought on the cause.
 

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Looking to buy...
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CSiJason said:
My best guess is the bonehead porter was sent to fill the tank up when you bought the car and the nimrod probably put 87 octane in it which in a 10.X:1 compression car, that spells trouble. Even with knock retard it may not have responded fast enough or great enough to back timing out to save the engine from severe detonation. This is my most logical thought on the cause.
I'd like to point out that according to your 2004 GTO owners manual (page 5-5) : "You may use middle grade or regular unleaded gasoline rated at 87 octane or higher, but the vehicles acceleration may be slightly reduced." So I doubt this would cause the type of problems described.
 

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Lower octane gas coupled with perhaps poor quality gas and/or some excess water in the tank due to it sitting around on a lot for months couldnt help much. I'm still betting it was bad gas plus low miles. The car "SHOULD" be able to compensate for ping and knock quick enough but if you get some really bad gas, it may just let off one good detonation that sends the ECU into a serious backdown mode on the timing curve for a bit which in turn will make the car continue to run like a pig.

Personaly, I intend to only feed mine 91 or better but that is just me.
 

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13 year owner
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16,384 Posts
CSi, that is meant for proper "break-in" of the motor, not it causing a misfire(s)! You should be able to pull it off the lot with the tires ablaze just as you should at 50,000 miles!

I wouldn't be surprised if it's a bad Crankshaft Position Sensor or a Cam position sensor. Perhaps a bad feed to the ignition system. These are CNP (Coil Near Plug) setup, which means that there is a coil for each plug.

Quick, I'm just north of you in West Chicago.
 

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2004 Pontiac GTO
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167 Posts
Discussion Starter #16
Hey neighbor...care to let me drive your GTO so I can stop these withdrawl pains??

I just spoke with the service guy...he said the tech determined that #1, #3, and #7 cylinder coils are not getting enough voltage to fire...but #5 is fine, as is the entire passenger side bank of cylinders.

Why is the #5 coil firing as it should, but the other 3 coils on that same bank are not? Replacement coils did not help. (??) They have called GM for technical assistance, so we'll see what they say. At least it appears they have pinpointed the area of concern. My questions are:

- Where do the coils get their voltage from?
- Is that source common for all coils?
- If so, that source would not necessarilly be the problem, right?
- Could this simply be software/programming related?

:banghead:
 

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I like boobs.
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Hmm, bad coil grounds? Something could have came loose and/or shorted when you first got on it when you took it out for a drive with your friend. Strange that it would be fine and then suddenly not after getting into the power hard.
 

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A Million miles and counting
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363 Posts
engine trouble?

Doesn't anybody drive their GTO just for the pure enjoyment? I don't think I've got mine past 3/4 throttle yet. I think it's just plain fun to drive. Maybe I'm just too old to be driving a car like this. But wait, I did give up a '92 Vette and a '93 Allante for this, maybe not too old. I get the best of both worlds this way, fast car----great ride.
 

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Cosmoso4 said:
Doesn't anybody drive their GTO just for the pure enjoyment? I don't think I've got mine past 3/4 throttle yet. I think it's just plain fun to drive. Maybe I'm just too old to be driving a car like this. But wait, I did give up a '92 Vette and a '93 Allante for this, maybe not too old. I get the best of both worlds this way, fast car----great ride.
im 22 and baby mine around, maybe because i feel out of my league with this car, its so nice to drive.
 

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13 year owner
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16,384 Posts
I wish I could tell you. It could simply be a bad ground in the wiring harness, it could be something else. I Really couldn't tell you. The Technician should be able to take all the codes he gets P0300 Multiple Random Misfire, P0301 Cyl# 1 Random Multiple Misfire, P0303 Cyl# 3 Random Multiple Misfire and P0307 Random Multiple Misfire.

Since these are all the same, in SI2000, he can go get GM's methodology and then a detailed troubleshooting list. That will take him right to it. Unfortunately I do not have remote access to this anymore, otherwise I'd get it for you.

Is this Village per chance? And I'm around if one would like to hear it. :D
 
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