8
questions

a/c never gets truck very cool ,feels like its getting cool then compressor kicks off,the temp @ the center vent never gets to 50 degrees,(all my other veh. get down to 35 deg.) and keeps trucks cold.What can I do dealer hasnt been able to fix.

Idles rough, had tb cleaned, keep oil changed every 3000
Acts like it's gonna die when at red light engine light comes on
For a day or so then goes off, uses more gas in summer

Had throttle body cleaned, changed 2 coils, spk plugs, air filters still same in winter ran good now getting warmer now doing the same, engine light comes on for a while then goes off idk help

Once moving if light pressure is applied, the rear brakes will chatter. Once the brakes release then when coming to a stop, they will grab a second before full stop. Has anyone else experienced this problem? My truck only has 48k miles on it.

the window goes up very little and comes down just a fraction of an inch.i have in channel deflectors on the truck. the dealer said that was the problem ,so I took them off. it still the same way . any solutions .

thank you

Today cool air was coming out about the speed it does in the low (#1) setting.

Engine: 2.8L duramax turbo diesel LTZ 4x4
power:132KW/346lb-ft
year:2012
Origin: GM under Thailand spec(same as holden colorado at Aussie 2012 spec)
Ref link: http://media.gm.com/media/us/en/chevrolet/news.detail.html/content/Pages/news/us/en/2011/Oct/1005_diesels.html

PROBLEM:
Truck running rough, engine not stable, at 2500-3000rpm @gear 5 to 6 then blowing a lot of black smoke followed by white smoke. when acceleration pedal is off it start jerking a while, then it fine again..sounds like not enough fuel at injector. I have tasted my MAF sensor to unplugged while running, and its fine, when i plugged it back , problem came.. is that a MAF problem or MAP sensor problem.. there is no vacuum leak, oil leak, and turbo VN vacuum is fine..please advice