Idle problem CURE!!!!!!!! Finally!!
#151
Maybe ill give this a try..cuz i have noticed at stop lights and signs or even when i just revv up my engine at start up my RPM's drop for a moment and go back up..or maybe im missunderstanding somthing..i just got my cobalt like 2 weeks ago..trying to learn stuff about it =]
#152
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#153
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Thread Starter
I have my car ripped apart now for a few weeks(Valve cover and supercharger are in getting polished) so I am going to install the Oil catch tank right away. I am sure once this is complete that I will not experience this problem again(I hope!!). Its very strange that the TB is already clogging up so soon after I found the fix for the problem but bottom line is that there is just way to much oily compound making its way into the intake and then the TB so having the catch tank installed to catch the oily debree will most definitely cure this problem and it should only be "air" making its way into the intake and the oil should collect in the tank. I will post pics asap and keep everyone updated on how it works out once the car is back on the road.
#154
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Hey guys, this is messed right up. I am the guy who originally started this thread and Ive learned alot of good information since my post. I havent driven my Cobalt much since I first cleaned the TB mabye about 500km and it had been running perfect but now its back!!! I have no idea why its sticking again soo soon but luckily enough I had ordered an oil catch tank in which I intend on installing within the next week or so. I picked up the oil catch tank off a seller from ebay for under $40 and I am positive that it will be money well spent. For those of you that do not know what this tank does I will quickly explain. The tank kit will integrate with the hose that connects to the top rear of your valve cover and connects to the air intake. This is the hose in which all the gunk that builds up in the TB comes from. Now with the tank intalled in between the air intake and the valve cover, all of the gunky s**t will collect in the tank with only the air passing through therefore no more buildup of this gunk in the TB. I highly reccomend that everyone having this problem should invest in these tanks not only because it will save having to clean the TB very frequently but also extend the life of your engine. The more this gunk collects some will eventually make its way into the engine and possibly cause some damage to the engine. I would like to also say that I am soo happy that I have been able to help so many of you out there with this problem because it was soo annoying to myself that I was at the point of just trading my car in regardless of the tens of thousands I already have invested so I am very pleased. I will also post pictures of the catch tank once installed.
This fix all didn't work for me one bit. Nice try though. Resetting the computer only delayed it till another day.
#155
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#157
I have had those same problems, it is such a common thing with cobalts. As soon as I installed my exedy stage III clutch and flywheel the problem went away. Good post for those who still have idle problems.
#159
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Ok i just clean mine, took it around the block, and it worked..very well. however; now the rpm's stay up alot longer then before. before the clean the would just fall, but now the stay around 2k before they die down. think i should give it a few days for the computer to adj?
#160
i also cleaned my tb and have the same result with the rpms. i cant remember back 3 years ago my car doing this. is this normal? even if i take it out of gear to coast the rpms sit right at 2k? my tb was caked with oil and gunk, black as pitch. had 104k miles on it, so i guess it needed cleaning. didnt have the idle problem, car just started to stutter on me at low speeds and figured it needed cleaning. but would like to know if a guy can damage the springs and stuff inside by manually moving the butterfly while cleaning.
#161
Senior Member
i also cleaned my tb and have the same result with the rpms. i cant remember back 3 years ago my car doing this. is this normal? even if i take it out of gear to coast the rpms sit right at 2k? my tb was caked with oil and gunk, black as pitch. had 104k miles on it, so i guess it needed cleaning. didnt have the idle problem, car just started to stutter on me at low speeds and figured it needed cleaning. but would like to know if a guy can damage the springs and stuff inside by manually moving the butterfly while cleaning.
#163
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wow...its really hard on the gas mileage...i try to coast alot. but i will say, this car is really running now!!! BIG difference. if you havent cleaned your TB, you gota do it!
#165
Senior Member
Coasting is not as good for gas mileage as leaving it in gear. You will get better gas mileage by leaving the car in gear. Fuel cut-off deceleration - when the car is in gear and you take your foot off the gas the car will cut off fuel and use the vehicle inertia to keep the car running.
#166
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Coasting is not as good for gas mileage as leaving it in gear. You will get better gas mileage by leaving the car in gear. Fuel cut-off deceleration - when the car is in gear and you take your foot off the gas the car will cut off fuel and use the vehicle inertia to keep the car running.
#167
in gear decelleration = fuel injectors shut off completely ...while coasting = your car is at high idle, around 1200 rpms, and still pushing fuel.
so, your mpg's will go up either way, but will go up more during in gear decelleration ....
#168
Senior Member
Exactly. When coasting of course you are still going to get an increase in gas mileage. But by staying in gear the car actually shuts off the injectors so you are getting even better mileage. As an example - when I first bought my car I used to coast down hills, etc all the time. My average MPG was about 24 maybe 25 MPG. Once I learned the car had deccelleration fuel cut-off I started leaving it in gear all the time and only taking it out of gear when stopping or the RPMs dropped below 1250 (of course if still moving like int raffic I will down shift at this point). I now average around 28 MPG and that is 50% city driving and sitting in traffic for an hour every day.
#169
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Exactly. When coasting of course you are still going to get an increase in gas mileage. But by staying in gear the car actually shuts off the injectors so you are getting even better mileage. As an example - when I first bought my car I used to coast down hills, etc all the time. My average MPG was about 24 maybe 25 MPG. Once I learned the car had deccelleration fuel cut-off I started leaving it in gear all the time and only taking it out of gear when stopping or the RPMs dropped below 1250 (of course if still moving like int raffic I will down shift at this point). I now average around 28 MPG and that is 50% city driving and sitting in traffic for an hour every day.
So does downshifting to slow down waste gas? Does it matter how high the rpm's are? Is the fuel automatically cutoff even above 3k rpm?
Last edited by PolishPauL; 08-06-2008 at 01:11 PM. Reason: Automerged Doublepost
#170
Senior Member
Even tho i can hear the exhaust, theres still no fuel goin into the engine? I always wondered why manuals get better gas mileage cuz in an auto the rpms drop to 1k as soon as u let off the gas. I know why now. Thanks.
So does downshifting to slow down waste gas? Does it matter how high the rpm's are? Is the fuel automatically cutoff even above 3k rpm?
So does downshifting to slow down waste gas? Does it matter how high the rpm's are? Is the fuel automatically cutoff even above 3k rpm?
#171
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Thanks for the Info.
My Cobalt just started with that idle surging problem a couple weeks ago.
Going to get cleaner tonite.
Just Curious.... If you have had or are having this problem, What brand of Gasoline are you using?
Wondering if the problem might be related.
I'm using Phillips, Shell and QuikTrip.
My Cobalt just started with that idle surging problem a couple weeks ago.
Going to get cleaner tonite.
Just Curious.... If you have had or are having this problem, What brand of Gasoline are you using?
Wondering if the problem might be related.
I'm using Phillips, Shell and QuikTrip.
#172
Senior Member
Thanks for the Info.
My Cobalt just started with that idle surging problem a couple weeks ago.
Going to get cleaner tonite.
Just Curious.... If you have had or are having this problem, What brand of Gasoline are you using?
Wondering if the problem might be related.
I'm using Phillips, Shell and QuikTrip.
My Cobalt just started with that idle surging problem a couple weeks ago.
Going to get cleaner tonite.
Just Curious.... If you have had or are having this problem, What brand of Gasoline are you using?
Wondering if the problem might be related.
I'm using Phillips, Shell and QuikTrip.
#173
Senior Member
Thread Starter
Ok, well we have completed our project with the balt (under the hood anyways). The catch tank is installed and we have ran the car for a while and its definitely doing its job. There is already a very small amount of gunk in the tank now and only "air" moving through the tb. I will post pics of the car in the next day or so as I am very pleased with how it is turning out.