at a stop
07-18-2007, 07:55 PM
#1
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at a stop
when i go to a stop i have a problem where my car stuters a bit and goes below 1000 rpms to about 500 and it does all the time when i am stoped. and i run nothing but 93+ in my car. i have never ran below 93 oct. any answers.
07-18-2007, 07:56 PM
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i have the same problem. what car do you have? any mods? i have a 2.4L and an gm intake. the people at the dealership seem to think its my intake but i think they are all retarded.
07-18-2007, 08:07 PM
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i have a 2.2. i run 93 in my car becaue it is more clean and it is what i have put in every car i have ever owned. this is the only car that has done this
no mods eather
no mods eather
Last edited by murph; 07-18-2007 at 08:07 PM. Reason: Automerged Doublepost
07-18-2007, 08:10 PM
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07-18-2007, 08:16 PM
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I would not be surprised if filling up with the RECOMMENDED gasoline, 87, will fix your problems. If you go to the dealer, that is probably what they will tell you. Your car is BUILT to run PROPERLY on 87, not 93+.
07-18-2007, 08:28 PM
#11
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Murph, its not getting technical. It is what our cars are designed for. 2.2's are designed for 87, 2.4's 89 or 91, 2.0's 93. The rating has nothing to do with cleaner fuel, octane measures detonation... read this thread:
https://www.cobaltss.net/forums/show...ghlight=octane
especially the threads by D4U2S0T he thoroughly explains octane. I was running 89 for a while but it obviously didn't help.
93 is not good for your car, detonation is occurring WAAYYY too late and is robbing power.
https://www.cobaltss.net/forums/show...ghlight=octane
especially the threads by D4U2S0T he thoroughly explains octane. I was running 89 for a while but it obviously didn't help.
93 is not good for your car, detonation is occurring WAAYYY too late and is robbing power.
07-18-2007, 08:35 PM
#12
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Murph, its not getting technical. It is what our cars are designed for. 2.2's are designed for 87, 2.4's 89 or 91, 2.0's 93. The rating has nothing to do with cleaner fuel, octane measures detonation... read this thread:
https://www.cobaltss.net/forums/show...ghlight=octane
especially the threads by D4U2S0T he thoroughly explains octane. I was running 89 for a while but it obviously didn't help.
93 is not good for your car, detonation is occurring WAAYYY too late and is robbing power.
https://www.cobaltss.net/forums/show...ghlight=octane
especially the threads by D4U2S0T he thoroughly explains octane. I was running 89 for a while but it obviously didn't help.
93 is not good for your car, detonation is occurring WAAYYY too late and is robbing power.
Octane alone won't retard ignition timing and detonation is not a normal (at least it shouldn't be) occurance. A detonation is a uncontrolled ignition (explosion) which can cause knocking. Him putting 93 Octane is not going to change his ignition timing nor will it cause him to detonate.
07-18-2007, 09:30 PM
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I think you're slightly mistaken
Octane alone won't retard ignition timing and detonation is not a normal (at least it shouldn't be) occurance. A detonation is a uncontrolled ignition (explosion) which can cause knocking. Him putting 93 Octane is not going to change his ignition timing nor will it cause him to detonate.
Octane alone won't retard ignition timing and detonation is not a normal (at least it shouldn't be) occurance. A detonation is a uncontrolled ignition (explosion) which can cause knocking. Him putting 93 Octane is not going to change his ignition timing nor will it cause him to detonate.
07-18-2007, 10:44 PM
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I think you're slightly mistaken
Octane alone won't retard ignition timing and detonation is not a normal (at least it shouldn't be) occurance. A detonation is a uncontrolled ignition (explosion) which can cause knocking. Him putting 93 Octane is not going to change his ignition timing nor will it cause him to detonate.
Octane alone won't retard ignition timing and detonation is not a normal (at least it shouldn't be) occurance. A detonation is a uncontrolled ignition (explosion) which can cause knocking. Him putting 93 Octane is not going to change his ignition timing nor will it cause him to detonate.
for those that don't understand octane, let me break it down very simply. octane is ONLY a gases resistance to detonation. nothing more. how does this affect your car?
to keep it simple, in our example let's say a car is supposed to run on 89 octane. that engine is set up to burn that gas to the fullest amount possible. the optimal point of detonation is called top dead center. or, TDC for short.
when you're using 89, which the engine is designed for, the gas is exploded at just the right time so that it forces your piston down, creating power.
now, if you use octane that's LOWER than you're supposed to, your engine is igniting it too quickly, before TDC. this means that your gas is exploding while your piston is still moving up. when the gas ignites, it bounces off the upward moving piston that wasn't ready to be moved back down, and creates "knock". not good for your engine.
it's the same but the opposite (doesn't make sense, right?) for octane that's too high. it burns slightly after tdc, which again is not ideal for power.
i hope this helps a little, i tried to keep it simple.
to keep it simple, in our example let's say a car is supposed to run on 89 octane. that engine is set up to burn that gas to the fullest amount possible. the optimal point of detonation is called top dead center. or, TDC for short.
when you're using 89, which the engine is designed for, the gas is exploded at just the right time so that it forces your piston down, creating power.
now, if you use octane that's LOWER than you're supposed to, your engine is igniting it too quickly, before TDC. this means that your gas is exploding while your piston is still moving up. when the gas ignites, it bounces off the upward moving piston that wasn't ready to be moved back down, and creates "knock". not good for your engine.
it's the same but the opposite (doesn't make sense, right?) for octane that's too high. it burns slightly after tdc, which again is not ideal for power.
i hope this helps a little, i tried to keep it simple.
I guess there is a pretty good article on wikipedia as well.
07-19-2007, 06:47 AM
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yes my rpms jump
no i do not have a check engine light
07-19-2007, 10:02 AM
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Murph, its not getting technical. It is what our cars are designed for. 2.2's are designed for 87, 2.4's 89 or 91, 2.0's 93. The rating has nothing to do with cleaner fuel, octane measures detonation... read this thread:
https://www.cobaltss.net/forums/show...ghlight=octane
especially the threads by D4U2S0T he thoroughly explains octane. I was running 89 for a while but it obviously didn't help.
93 is not good for your car, detonation is occurring WAAYYY too late and is robbing power.
https://www.cobaltss.net/forums/show...ghlight=octane
especially the threads by D4U2S0T he thoroughly explains octane. I was running 89 for a while but it obviously didn't help.
93 is not good for your car, detonation is occurring WAAYYY too late and is robbing power.
07-19-2007, 10:30 AM
#20
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Another Rhody! Where abouts in Prov are you?
Last edited by OrngBalt; 07-19-2007 at 10:30 AM. Reason: Automerged Doublepost
07-19-2007, 10:52 AM
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07-19-2007, 11:08 AM
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hahah ok... well i told you to correct me if i was wrong. I am wrong.
Now everyone stop wasting or trying to save money and just use the damn gas that they tell you to use... you are hurting more than helping.
Now everyone stop wasting or trying to save money and just use the damn gas that they tell you to use... you are hurting more than helping.
07-19-2007, 08:25 PM
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I'm not sure the higher octane gas is causing that much of a problem. I ran 93 octane when I got my car, for the same mistaken belief. I ran it until I broke in the engine at 500 miles, then alternated with a tank a month being 93 and the rest 87. I never had a problem with detonation, nor did I have a problem with it idling rough, and dropping down to 500rpm.
I'd run it to the dealership if it's under warranty, and beat them until they look at it.
I'd run it to the dealership if it's under warranty, and beat them until they look at it.
