Just had a quick question, this will be my first winter with a diesel and i was just wondering when is a good time to start plugging it in to keep the block warm.I live inTN and the temp at night is in the upper 40's. Is now a good time to start plugging it in?

 

If everything is working right, you really don't need to plug it in until about 10 *F IIRC.

 

We see temps almost 30 below at times. The only time I plug mine in is when the temp is forcasted to be below 0. It will start with no problems as long as everything is operating normally like Mark said.

Sarge

 

With 15W40 dino oil, I have reliably started it without being plugged in at -20C or about -4F.

-40C is probably a different matter.

 

ok thanks for the help I wasant sure. it has never got to be 0 or below since I have lived here. usually see single digits around 8 degrees or so but not usually until the end of dec. beginning of Jan so I should be ok for a while. thanks again.

 

I plug mine it when its gets below freezing. Or so. The only reason is the heater heats up quicker when its plugged in. But thats just me. Other than that it starts fine even when its in the single digits with out it plugged in.

 

I run 5W-40 synthetic in the winter and never plug in.

I'm in New Hampshire, where I regularly ice fish in late January on lakes that have two feet of ice on them. That's cold.

 

The block heater is needed when it gets really cold, but the key to winter starting is to use 5W-40 synthetic in the winter. In your part of the world, if you do just that, you won't have any starting issues. This engine won't cold start well (or at all) if you have the summer viscosity oil in cold temperatures.

My 6.0 stays outside all year and we regularly get -40 or worse stretches for weeks at a time during the winter. She starts every time. When it gets really cold, I'll give her a few hours of block heater plug in before start, and I have a diesel heater that I use most mornings also, but the key is still the synthetic 5W-40. Remember the majority of the oil sits in the pan and never gets the benefit of pre warming. If you use 15W when its really cold, you may get a start, but then you will have poor oil pressure while the poor girl tries to suck that thick goo and push it through the engine - a recipe for accelerated wear.