Is this normal? I have 43,000 miles so far and the last 1,000 I have noticed a rough idle in the morning at start up. It's never cold where I live. I change oil/filter and fuel filter every 6K.
I've also noticed my overhead lights will continually dim and brighten at the same time as the rough idle. Lately I've been using the cruise control increase in idle speed to get the truck going before I leave for work, that gets rid of the idle and dimming of lights

thanks Jamie

 

the dimming lights are probably the grid heater. (see grid heater thread)
rough idle when cold is just a quirk of a diesel. you might try adding an engine block heater, or covering the engine with an electric blanket at night.

just dont forget to remove it before you start the truck.

 

Thanks, I use the block heater when it's below 40 just to have warm heat in the cab.

Jamie

 

it should help get over the rough idle faster too.

 

Jaimie - this is normal. In colder temps it will idle a bit rougher until it's up to operating temp. When you first start up, the grid heaters will cycle, which is why the lights dim, and the voltmeter drops below 14. I prefer to let the truck warm up/idle/high idle until the grid heaters stop cycling and the voltmeter comes back up to normal. Some people prefer to just drive off. I know the manual recommends at least 30 seconds of idling.

PS - fuel filters last a lot longer than 6k, you might want to try doing those every other oil change if that's your interval.

 

Lightman, I know I guess it's a peace of mind thing b/c my truck is how I make my money so I don't mind being a little **** about service intervals. What I've been doing is cranking the motor wait about 5 seconds then engaging the high idle to 1500rpms for 30-45 seconds or longer until I'm ready to drive off... does that sound like an acceptable routine in the morning? All this really looks like I'm splitting hairs (****) sorry. I just want to do what's best for the truck.

Jamie

 

I've been traveling to Wellington, FL every 4 weeks since November. There have been a number of mornings that I've been down there that it has been quite chilly, though not like Illinois. And Wellington is quite a bit further south than Ocala. Try plugging her in and see if that helps. When I plug mine in, she'll start up like it's 90+ degrees out even though it may be below zero out. Or maybe our northern trucks are a bit tougher than their southern cousins!!!

 

Jmac, I typically wait till the heater grids are done cycling - which you'll know when the voltmeter goes back up. I usually let it run for about 15 seconds before kicking it up to high idle (we're talking 0-25F though) I'm sure your truck will be fine either way - FL doesn't get that cold, and the fact you're waiting at all and taking it easy while it's cold will go a long way. I'm sure there are a ton of these trucks out there that get started and stomped on all the time and are still out there running fine..