Is my block heater working ?

[davem]

I have a 2001 Explorer XLT, 4.0 V6 with 106,000 miles on it. I've owned it since 2003, when it had 35K miles.

I've never used the block heater until now ........ now that my son is driving it, it sits outside in some cold Minnesota weather.

I've plugged it in a couple of nights (ie plugged in for about 6-8 hours), and the Explorer starts the next morning, but I'm not sure the block heater is working. I felt the lower radiator hose and it was not warm. I don't know if this is a good test or not. (I know the extension cord has power - I verified it by plugging in a trouble light.)

How can I verify its working ? What are some things I should check ? Where is the block heater located ?

Thanks.

Dave

 

[Dan Whitaker]

The block heater does not circulate the coolant. That is why the lower hose is not warm. Typically block heaters are installed in one of the freeze plug holes.

 

[vroomzoomboom]

normally you can hear them crackle (it will sound like a tea kettle) within 3-5 seconds after you plug them in when they are first cold. thats the way i see if they are working. also, the block heater is located on the first freeze plug hole near the front on the passengers side of the motor block.

http://www.explorerforum.com/forums/showthread.php?t=257152

 

[pricetag2]

When I disconnect mine in the morning, I can hear a slight hissing sound that stops as soon as I pull the plug. Warm air does not immediately blow out of the vents but it does heat up very quickly. Hope this helps.

 

[KillerB74]

You should also see the pronged end of the cord spark if you slowly plug or unplug it in your outlet. You might have to try this a few times to see the spark and it is much easier to see the darker out it is.

 

[vroomzoomboom]

When I disconnect mine in the morning, I can hear a slight hissing sound that stops as soon as I pull the plug. Warm air does not immediately blow out of the vents but it does heat up very quickly. Hope this helps.

the way a block heater works is it is not supposed to make the antifreeze in the entire cooling system warm, only in the block, and even at that it will not be boiling hot. you have to remember, all the coolant in the rad, and heater core are still going to be cold.

 

[davem]

While changing oil this afternoon, I could see the block heater (thanks to those who posted pics/links) and the wiring appears intact. I guess I'll listen really close when I plug it in to see if I can hear something.

I was talking to a guy about it today, and his opinion was that the engine should spin at start up just like it would in the summer. I would not classify my experience as at that level.

 

[gijoecam]

Depends on the weather, but it's usually only about a 600 watt element. That's not going to make the coolant toasty, but should make it warmer than a cold-start. Also it's not going to keep the oil in the pan any warmer than normal either, nor will it keep the battery warm. It's going to help with a faster warm-up, but it's not going to keep the engine near operating temperature.

The first light snowfall you get on a calm night will show up as a melted spot on the hood if it's working. The quickest, easiest way to check if it's making the circuit would be to check for continuity through it with a multimeter. If it's open, there's no circuit there.

-Joe