i have a engine block heater cord on both of my trucks but have never had to use it and was just wondering how exactly they work. My brother has a 95 cummins and tried his and it really didn't make a difference.
thanks

 

it circulates your coolant to keep you block warm and makes for easier start up and warm up time in cold weather

 

On a cold night it might only raise the coolant temp 20-60 degrees. This is more than enough to assist starting efforts at -40 degrees.

 

It is just a heating element, like your home water heater. I have mine on a timer, comes on 3 hours before i leave in the morning. Engine is usually 70*-100*ish. Depending on how cold it is out side.

 

If you use it alot, you may want to consider getting a short heavy duty exrension cord - like 1 or 2 ft. Keep this plugged into the block heater cord and then plug the regular extension cord onto that.

Over time, its not unusual for the prongs on the heater cord's plug to become loose. Then the circuit is opened and no more heating. Years ago,the heater cords used to cost about $25. Not sure what they are now.

 

if the element or cord has an open in it, it won't work so it won't make a difference.

*EDIT* ah I didnt read barneys post

 

My block heater makes a big difference. In clod weather w/it plugged in, no wait to start light, w/o plugged in I get the W.T.S. light.

Floyd

 

We HAVE to use block heaters here, right now its -35 and -45 with the wind (not that it makes a difference in vehicles). I use an oil pan heater also, boy with those 2 plugged in, the WTS light is on for about 5 seconds and the old girl fires right up and does not miss a beat.

Its been cold like this for the last week and a half. Supposed to warm up to -20 by boxing day.

 

Another reason to use the block heater is to help reduce the current through the starter contacts. A warm, nimble engine won't need as much juice to roll.

http://www.fostertruck.com/dodge/starter%20faq.htm

 

Yup! Does not get hot enough to open T-Stat or circulate coolant... but big difference in warming entire block for startup.
I use a timer...3 hrs... and on a 20* morning, my coolant is at 125*F. IF I run the heater all night ...140*.
Fun playing with the Adrenaline/Pulse. It reads coolant temps, IAT temps, oil temp and even fuel temp (at the VP-44).

Can't report coolant temps on a sub zero night, cause we don't get them

RJ

 

You would need a pair of battery warmers. This reduces the voltage drop because of the temp. Makes the battery last longer also. Mine has a t-stat wired into the receptical to come on at -4*C.