2004 Chevy 2500HD
Ext Cab-LT


In the colder weather the truck has been running a little rough @ a stop- in gear. When this rough idle happens it seems to smoke alot. It does not do it all the time, did not know if fuel would cause this or a gelling issue. Dealer cannot detect anything unless it trips a code--They Say!:mad:
Any advice?

How cold is it getting? If you have summer fuel in your tank you may see some issues around 30-40 degrees. Once the truck is going there is a fuel heater that will keep the fuel warm. Ask your gas station if they blend their fuel for the winter months. If they don't, find a new gas station or use an aftermarket winter fuel additive.
I live in the Chicago area. All the fuel suppliers up hear have to blend their fuel due to the temperatures. If you live somewhere where it only gets cold every once in a while or if you are on the border of the snow belt the fuel suppliers may not blend it automatically.
You should only notice a rough idle and maybe a little smoke for the first few moments after you start the truck on a cold day. After that, it should go away completely, and not return until the next cold start.