I have an 07 h3 3.7 with and occasional rough idle. Cleaned the maf and throttlebody, has new intake gaskets and vvt solenoid. I can get the idle to smooth out if i turn my ac on then off...

 

Also has new ac delco plugs, pcv hose.

 

Someone on here changed where they fueled up and problem was solved. This has been beat to death on this forum. Do a little searching. You got all the basics covered.

 

True. Cheap gas is cheap for a reason.

Always use quality gas, they call it top tier in many parts of the country.

 

Ive tried every station in town thinking that was the problem.. using top tier now. I find it weird that when i turn my ac on it smooths out., doesnt make sense.

 

 

I dont think its just how it is. Some days it runs smooth others it will be smooth then i come to a stop and it has a bad vibration.. steering wheel all over the place because of it. Ive notice every now and then when i come to a stop or brake hard the rpms drop below 500, or the rpms wont drop smooth it will be choppy. Like maybe a throttle postion sensor but i think you have to replace the throttle body to replace that not sure. Correct me if im wrong. It didnt do this when i bought it had 107k on it then now its at 143k.

 

 

Its never had check engine light or stored codes except for the vvt solenoid and the thermostat... found out about the intake gaskets by checking the bolts, and most of them backed out on there own. So i figured that was what was causing the rough idle so i changed them, and it got better of course but maybe twice a day or so it does this... so one day i turned my ac on let it kick in and turned it off and it smoothed out.

 

Forgot about it but another thing i had to change was the plug for the map sensor because i moved the wiring harness for it and the motor died.