Hi everyone, I am new here and am deciding on a truck. I'm not sure what that little box is called, but I know you have to plug it in for a diesel if the weather is too cold. Here's my question: how cold is too cold? When do you have to plug it in to protect the diesel in winter? It's the 2005 Cummins I'm considering.

Thanks, Eileen

 

usualy you start to plug in the block heater at around 40*

 

What he said goes if you want instant heat, but the engine will start without help down into the single digits. Below freezing it makes starting easier to plug in, but it's not really required until temps get down around zero. In St. Louis I doubt you see weather cold enough that the truck would not start if unplugged. With all that said, I plug in when I can below 40 because I'm a wuss and want heat fast.

 

Thank you. It sounds like I won't have to worry about plugging it in unless something unusual happens here. Our outside outlet sometimes isn't terribly reliable, so this makes me feel better.

Thanks, Eileen

 

I usually plug in when it gets below freezing. I just put it on a timer which turns on a few hours before I leave for work. It's great having that 'wait to start' light go off right away.
I usually put an anti-gel in the tank when it gets into the teens.

 

To save a electricity some put their block heaters on heavy duty timers to only use the heaters a couple of hours before you need the truck. Since I ahve 110 that close to the truck I also put a ceramic heater in the cab of the truck. I like my seat toasty, and it clears the windshield.

Can you say "seat" infront of a lady?

 

mine has started in -10 degree weather without a problem. its usually around 0 degrees in the mornings and she fires right up without plugging it in. when it gets down below -5 i usually do plug it in though.

 

Thanks everyone. This info is really helpful. Eileen

 

I got my 99 24 valve started at -15 after 16 hr soak with no plug in (no place to plug in at work or apt). Makes piles of smoke, the PS groans louder than the motor, sounds like the whole garbage truck fleet is running in the parking lot.

The 2 powerstrokes didn't make it in Friday and one of the 2 duramaxs didn't either haha LOL

bring on the cold haha.

bentwings

 

A plus for plugging it in is that it will use a lot less fuel when warming up. I tried it and it used a lot more fuel until it warmed up without plugging it in. Plugging in saves fuel bottom line.

 

That's a good point, risking higher rate of blow-by, although reduced oil circulation should be enuff reason to plug in. If you can't you can't, but if you can, you should. Might help the starter last longer and help battery longevity from repeated, large draws too. Might even help against condensation in the fuel lines from drastic temp changes.

 

Actualy it does not help either of these 2 things. The block heater is in the block and heats only the engine coolant not the oil or fuel. The oil is sitting in the pan under the block out in the open and is not helped at all buy the heater and the fuel is in the lines running back to the tank. Neither of these are anywhere near the heated coolant. It mearly alows your truck to start eisier and thats it. It takes the same time to get oil circulating when its pluged in as it does if it was not. It will not help keep the fuel from gelling up at all. If it gets to cold your fuel will gell just as fast as if it was not plugged in. It does however save on your battery like you said.

 

I follow y'all on the plug in and agree. It definitely costs fuel an wear and tear. My mileage is down about 3-4 in the really cold (-10) plus I have to drive it around the long way some 10-12 miles to warm it up. The net effect is about the cost of 4-5 mpg. I probably use 10 12 gal a week just driving around looking at the scenery. So it $20-25 week plus the reduced mileage.

Here is a fix that I've been giving serious thought to.
There are several small generators around 1000 to 2000 watts that will drive the block heater easily. You can easily bolt one down to the bed. You can just start it up and let it run as long as you want while you are at work or out in the field. It should work I would think. They run about $150 to $300 but they would be paid for the first tow you save. I think they run about 1/2 gal per hour of gas. So about $0.80 an hour. You could also add one of the magnetic oil pan heaters if you wanted.

BTW I did check the under hood temps with one of those hand held temp gages the one time I was able to plug in at -10. Most everything under the hood was a good 20-30 deg warmer than outside. The block and head was at 60 deg F. so they do heat things up. As for the oil itself I didn't check the pan but the oil pressure came up a lot faster heated than at -15 not heated.

I'm not realy looking at the cost of the unit so much as the wear and tear on the truck. It surely doesn't do it any good to do super cold starts every day without a good warm up afterwards. I supposed I could figure out another good use to justify the cost if the bean counter (wife) wanted.

What do think??

bentwings

 

According to my infrared temp gun the bottom of the oil pan was 40F on a zero degree day after plugged in for 12 hours. The block heater even raises the temp in cab a bit, 20° on the same 0° day.

The coolant actually circulates due to convection when the block heater is plugged in, warming the entire engine, radiator and heater core.

 

Conductive Heat Transfer. 'Nuff said!