When to plug in block heater?

RobertN · Dec 23, 2003

My Cummins Dodge has a block heater. It does not get very cold here. I did plug it in, just for giggles, on a 38F evening. It was nice to get in the truck in the morning and have warm air from the heater right off the bat. I have had it for two years, but have not yet had a real need for it, and probably won't plug it in again any time soon.

For you guys in cold country, what temp do you wait for to plug you truck, tractor, ect in?

JDgreen227 · Dec 23, 2003

On our '92 Olds the heater gets plugged in when the temps stay below 20-25 degrees at night. Ditto for our Y2K GMC. The Olds has an electronic dash with digital readout and with the heater plugged in the coolant temp is in the 88-89 degree range before startup.

Bob_Skurka · Dec 23, 2003

We plug in our fleet when the temps drop into the low 30's and keep them plugged in every night after that until spring. From our experience we can have 5 cold days in a row, followed by a day in the 40's but that warm day can turn into a very cold night and so we just instruct our drivers to plug them in every night. I can't tell you what the electric bill is for doing it, but I don't suspect it is very much. We have about a dozen large diesel trucks plugged in each night. When the temps drop into the minus 10 and colder range we try to move things around in our building and bring the trucks into the warehouse area and even park some down the forklift aisles. We also use propane torpedo heaters to warm some of them by throwing a large tarp over the cab of the truck so it touches the ground on both sides and then we blow the hot air on them with the heater. Our biggest problem is not frozen blocks, but frozen fuel lines and frozen diesel tanks. The diesel gums up and turns into something similar to gel that doesn't flow very well. We are in northern Indiana just a few miles south of Lake Michigan and the temps here are not too extreme. We get one or two really cold snaps a year and we feel sorry for the guys in Wisconsin and Minnesota on those days because they get REAL cold a lot more than we do.

Bob_In_MN · Dec 24, 2003

Tractor get's plugged in when it's below 30. It starts when it's that cold, but starts much easier when plugged in.

My current truck is gas so I don't plug that in until it's below 10. When we're ice fishing on Mille Lacs, we bring a small generator in case we need to plug the trucks in. We've seen 30 below on the lake a couple of mornings and it's nice to know you have a block heater then.

By the way--someone (in a different thread) asked if you can tell if a block heater is working right when you plug it in. On both my truck and tractor I can hear it right away when I first plug them in. Not sure if that's the case on all block heaters though.

Bob

JDgreen227 · Dec 24, 2003

Only way I can tell if ours works is because the Olds has the digital temp readout, never heard (pun intended) that a block heater makes a noise. Can you describe the sound?

Egon · Dec 24, 2003

It's sorta a hissing buzzing sound. You may have to wait a few seconds after plugging in to hear it if the coolant temperature is low enough.

They will cut in and out depending on the coolant temp.

Egon

RalphVa · Dec 26, 2003

I'd plug it in when it goes below 30 or 40. It'll give you warm water for heat and help your oil get flowing quickly. Most wear on an engine is at startup. If you don't have 5Wxx or 0Wxx oil in for the winter, it'll take a few seconds for it to be pumped up to the valve gear. With the heater, I suspect it'll pump up there pretty quick. However, the block heater doesn't heat the oil.

We have a block heater for the Benz but don't use it now, as our garage usually stays above about 50. Wife gets heat from the heater once she drives one mile to the other end of our street.

Ralph