So my truck sounds like it is missing, and has a rattle sound at every miss, when the grid heaters are on. I can hear the miss by the engine and in the exhast note. I know the lights and the voltage gage should fluctuate but is this miss normal? It idles as smooth as can be after the heaters shut off.

 

Mine sounds like its missing when they come on but I know its just working to run the alternator when the heaters kick on.

 

i dont know about the rattle, but if the engine sounds like its *surging* more than missing, you should be fine. I guess those grid heaters really pull a lot of power, and the engine is surging as a result.

 

Mine sounds the same since the software update. Usually only when it's cold.

 

It doesn't really sound like its surging. It sounds like its dropping a cylinder, especially from the tail pipe sound.

 

Thats how mine sounds. I wouldn't worry too much. Those heaters draw over 100 amps and that a pretty substatial load on the alternator while your idling. Mine sounds really bad when I forget to plug it in and have to start it at -20'F then you can watch the tach move a couple hundred rpms when they kick on.

 

well I won't worry to bad I guess. I just bought this truck and am still a little worried about my decision. I seem to notice every little thing and get worried. That and I have about 1000 miles left on warrenty and would like to find problems before it expires. Thanks for the replies guys.

 

just out of curiosity, how does it start when its cold (where are you located)?

 

Beh, mine does that too - 2006 with 12K on it. It'll even do that when I kick the high idle on. I think it's a normal result from the amount of power the grid heater pulls. It's not *quite* a miss on mine. More like a quick stumble. Sounds like the engine gets b*tchslapped when it's not expecting it. I've watched my tach closely when this happens and the rpms don't change a bit.

 

Mine does the same thing. I guess it is normal.

 

Its normal to hear the engine pull down alittle when the grid heater kicks on. It should only pull down for a second then go back normal idle.

 

I guess it sounds like this is normal. My tach doesn't drop when it does it it just sounds like it slightly stumbles, and rattles at the end of the stumble. It has been between 28f and 45f when I usually start it. It does it whether its been pluged in or not. All my buddies have second gens so I cant compare to theirs.