A Weekend of throttle body cleanings

[Dad_The_Mechanic]

I have 4 cars:
2006

Topic

[John B Kobberstad]

Quoted From Dad_The_Mechanic:

The cobalt and Montero both had the same problem, rough Idle and erratic idle. I reset both computer systems by leaving the battery disconnected over night, reconnecting the batteries and letting each vehicle idle for 10 minutes. This took care of the Montero. The cobalt however still has a high idle problem. The car idles at 2000 rpm unless at a dead stop. Any Ideas?

I just did a throttle body cleaning on my wife’s 1996 Neon last weekend. also cleaned the IAC motor that was attached to it with carb cleaner. What a gunky mess (it’s got over 270,000+ miles on it and I don’t think it’s ever been cleaned I got it with 130,000 on it). Does your throttle body have the IAC motor in it and did you clean the Idle Air Control motor? It may be that the Cobalt may need to be driven a bit to get the computer to get the IAC adjusted.

[college man]

when you cleaned the TB on the Cobalt. Did you remove it to clean it?

[EricTheCarGuy]

Quoted From college man:

when you cleaned the TB on the Cobalt. Did you remove it to clean it?

I need to make an update to the video I did on throttle cleaning as we get this a LOT on the forum and it usually happens after the throttle is removed. Also if it’s drive by wire you should not clean them. There have been instances on this forum where a DBW system was cleaned like that and had subsequent idle issues, the only fix was to replace the throttle body.

Throttle cleaning should only be done if the throttle is sticking and NEVER on a DBW system, I also do not recommend removing the throttle assembly for cleaning.

[Dad_The_Mechanic]

WOW,
I did not clean the IAC and did not remove the throttle body. I have been driving it now about 2 weeks post repair and the idle problem seems to have slowly gotten better, however the return to idle is still slow. I hope that a video about this makes it to production. Thanks for all the comments and advice.

[college man]

Go into our question and code search.Type in chevy cobalt.
click the forum and look for the thread on cobalt high Idle.
alot of reading there that may help. theres also a link under
one of my posts how to reset the high idle condition. you
could give it a try to see if it will help. the last guy had to
replace the TB

[EricTheCarGuy]

You might check the throttle cable and the cable return, if the cable is sticking or too tight it can cause it to be slow to reach idle.

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