So I cleaned my TB today and it did Indeed Help Big time with the Horrible Idle, I think once I fix my Exhaust Leak it will really help....But Thanks for this Awesome Thread!

 

just cleaned mine. first time in 97k pretty bad but cured it. no idle hunting.

 

My car's going into the mechanic tomorrow, and thanks to this thread, I'm adding a new task to the list. I had assumed that my irregular idle was merely the result of having the supercharger replaced with the turbo, but maybe something simple like this will smooth everything out. This is why a forum like this is really cool.

 

im having the idle surge problem myself. i just put a zzp stage 3 kit (basicly) and zzp intake onto my car. intake went on a week before, no issues. put the rest of the kit on and am being remote tuned by zzp, on one of the tune revisions it started doing a cold idle surge till it hits around 130*f, then it quits. of coarse my defrost is on at this time of year, so of coarse the a/c is on. also, throttle body was off and cleaned just over a month ago when i swapped blowers.

anyone run into any other issues that cause the idle surge? im thinking it may be tune related, however im waiting for a nice day where i can get a proper data log to send in.

 

your a f##$ing life saver ive had this problem for a year now and had tryd everything and spent 100s of dollars who knew a 4 dollar bottle of tb cleaner would fix the problem.
everyone that has this problem CLEAN THE TROTTLE BODY!!! dont just think about it DO IT. my car hasnt ran this good since the day i drove it off the lot.
THANK YOU!!

 

just wondering after i reconnect the throttle body and start to screw it in is there a certain amount the screws have to be thightened to?

 

totally fixed! i **** myself when it worked...no really true story

 

ok new problem arose ever since i cleaned out my TB i hooked everything back up and now i get a eng pwr reduced error but when i **** with the connector for the valve controller the error goes away..ill try a new tb but if anyone has anyother ideas id love to hear them

 

Yes
the LSJ Power Book Reccomends 89 Inch Pounds.
I cant get the torque wrench on all four bolts though, so I just snug them up. As long as its not loose, or stripped the torque here isn't very crucial.

 

Just sounds like you didnt connect everything back correctly. Intake leak at the TB possibly. Double check everything.

 

Worked for me, thanks man. so simple yet so effective... except my car has 120,000 kms on it lol

 

I did mine on my car cause I was in a hurry. But I had my Rpm's idle around 1500 when i pushed the clutch in when I was about to downshift or come to a stop. I work at Cadillac and I know when we do it on the escalade it has a high idle. What I did was reprogram the PCM on the car. Also if your having idle surge with the a/c on, this reprogram fixes that too. It is now running perfect. Just thought I would let you guys know.

 

Ok, I had my oil changed today, figured I'd go ahead and let the Valvoline guys do a 3 part fuel system cleaning (afaik all that's been done to it is fuel additive I've used every time I got an oil change) since I've left I've been idling high (around 2k, can let off my accelerator and it'll coast 35-45MPH), checked back with them and they said it may take 24 hours to have everything settle back down after the high octane flush and cleaning the throttle body, went to park it at my job and it jumped up to 3k, does this sound right (doesn't to me but I'm a computer guy, not so much a car guy)? Said to come back tomorrow and if it was still acting like that they'd have to reset the sensor by unplugging the battery.. (again, being a computer guy, I understand the power of the all-mighty reset... but ehhh?)

Not throwing any codes, but she's just not acting right.

2006 Cobalt SS NA

 

It is common for the idle to run high during coasting(clutch pedal down or in neutral) while coming to a stop. Especaily true right after cleaning the throttle body and intake system. I don't remember mine ever running as high as 3000 rpm though. Typically I would experience it idling up to about 2000rpm for a few seconds and then drop back down to 850 rpm and idle normally at the stop light/sign. If it goes up to 3000rpm and stays there without coming back down within 3 to 5 seconds then a reset might be in order. I'd run it for a couple days, say 100miles worth or driving. If it persists take it back and have them do the reset, if the reset doesn't cure the problem have them check for a loose or damaged vacum line. A line could have cracked or just not been put back properly, especialy if the car has high miles on it or isn't kept in a garage. those lines can dry rot with age so don't discount that entirely.

 

It's just freaky letting off the accelerator and having it either not drop or drop for a second and then jump back up to 2k. For it to drop back to the normal 850 range I have to have been stopped completely for 2 seconds, otherwise it wants to sit 1125 - 1250.
I took it through a 20 mile circuit afterwords just to see if it was remnants of the system being cleaned but jeez.
Thanks, I'll give it a few more miles and see how it does after checking the lines and stuff. She's at 74k miles and no garage (girlfriend took it lol)

 

These engines did this alot even brand new, I remember mine doing it alot when new. Then i forgot all about it after break in, and when at 25,000 miles I had the injectors cleaned it started doing it again and I remembered it. They'll get a rough idle to and need the throttle body cleaned about every 15k or so even though the book says every 30k. I notice the rpm go up, then come back down after each cleaning.

 

Hey Guys I was suffering from this weird idle issue for a day now. Did this and cleaned with turpentine + toothbrush.. what an improvement.. solved all of my issues plus it was easy.. this may be a bad thing because I think I am a mechanic now LOL!

 

My RPMs flutter for about 10 seconds right after i start the car cold.. but then it clears up completely after car is warm... Is this the same thing? Cleaning the TB would help?
thanks

 

Thank you sweet baby Jesus for this thread! I thought I was going to have to spend some $$$ to get it fixed. Everyone seems to have had the same issue as I am having currently, I cannot wait to try this out. THANK YOU SO MUCH!

 

Angel, I would like to thank you for this obvious yet unobvious fix. Just bought my Cobalt yesterday(2006 LS not SS) and when I slow down at a stop sign or red light with the A/C on the RPM's would die down and the car would vibrate from the stain on the engine. It has ~75,000 miles on it. Anyhow, I read through this entire thread and decided I would take the plastic intake off to see what the TB looked like and it was quite dirty. So, I took a rag and did a very simple wiping around the flap and the inside of the TB itself(I didn't unbolt it). Took it for a ride and it seemed to have solved the problem.

I feel bad that the fix has only been temporary for you but hopefully the satisfaction of giving this tip to people has balanced out the pros and cons.

Tomorrow I plan to buy some TB cleaner and take the TB off and clean it correctly. Again, thanks for this tread and I hope that your issues have since been fixed.

THANKS!!! Yes, the caps mean I'm yelling!

 

if your stock get the gm update for the ecm.. its a different car

 

Thank god for this forum! I was going crazy trying to figure out what was wrong with this stupid idle. Thanks!

 

I have this same problem. I will be trying this out this weekend. Everything you all are describing is exactly what's happening to mine.

 

So I just tried it this morning and nothing its actually worse now lol does it take time to work?

 

Worked for me as soon as I turned the car back on!