Block heater operation

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HoosierJeeper

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I have an appt tomorrow morning to get the Mopar engine block heater installed on the KJ! :signs1:

It's usually parked outside, I'm wondering those that have them, what temps do you use them at and for how long do you plug in? Here it's going to be about -15F below (lows) for the next few days and usually around 0F for a low. I was thinking about setting the heater on a timer and having it come on for about 2 hours before the KJ gets driven? Is it possible to do overkill?

Thanks!
 

al7fi

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Up here folks usually plug in below 20F 2 hours before time works well.

Sure makes a difference when it gets to sub zero.
Warms up lots quicker too!

I do leave mine in longer when its not expected to get above 0. Have an outside duplex outlet switched in the garage . Timer would be better but nothing in use thus far.

Love it. New Traihawk will have one on it also!
 

HoosierJeeper

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Cool...thanks for the input. If it's constantly below 20F, is there harm in just leaving it plugged in? Also, just so I know what to expect- how warm is it when you start it? Like does heat blow near instantly?
 

Porkchop

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I use the 2hr timer method on my Libby but I have left it in all night no big deal it can only get to a max safe temp anyway.
 

LibertyTC

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HJ that block heater is great at keeping it warm overnight if left plugged in all night.
If your KJ sits all night at those -15- to -20F temps without plugging it in, I would have it on for 4+ hours, from the timer before u leave. The stock block heater only consumes about 430 watts per hour, so it is a bit slow initially to get it warming when it's that cold outside.
If you use synthetic engine oil like Mobil 1,you wont have to worry about the thicker oil harder to start issues. If you are running dino oil, then leave it plugged in all night.
The other thing about the cold is the battery, you loose 50% of the cranking amps at those temps, so if u can also put a trickle charger on the battery at the same time as the block heater plugged in, your battery will be guaranteed ready & say thank you.
 
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HoosierJeeper

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Thanks for the input guys! And good to hear from you TC...been a while, eh? :D

So I guess if it's below 0...all night and if it's below 20 do maybe 3 hours? Does that seem good? I guess I'll kinda get a feel for it to. I've never had one/used one before.
 

LibertyTC

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Ya HJ after KJ is cold plug it in and test ...
try 3 hours and put your hand on the rad hose...how warm does it feel?
You can also turn the key on and read the temp gauge or other electronic OBD2 reader temp and get a feel for what is warm and what is not LOL...
 

al7fi

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Cool...thanks for the input. If it's constantly below 20F, is there harm in just leaving it plugged in? Also, just so I know what to expect- how warm is it when you start it? Like does heat blow near instantly?

No harm in leaving it plugged in as long as you want (other than increase in electric bill).

It will not blow "heat" instantly but it will be a tad swarmer than if you di not have it plugged in. You will get a warm engine a lot quicker with to.

I have never had to use a charger trickle or otherwise on ,y 03 Liberty. Original battery last about 8 years and was replaced when CCA dropped to 350.

It sat in a lot at the place I launch my snowmachine for 2 days and nights with temps at -20 or more at night. When I rode out it was showing -16 and though it did crank slower than normal, she fired right up.

We don't get temps like they do in Fairbanks or other interior locations, but sub 20s are not unusual.

at the timer setup is a good thing. I just never picked one up.

Stay warm ands enjoy!
 

profdlp

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And here I thought it was cold in Cleveland! :flamethrower:
 

CactusJacked

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Just plug it in overnight, that's how engine heaters are designed to work. No need to over-engineer or bother with any unnecessary timer add-ons. For the battery, what kills output is the cold. You can get a battery wrap/heater that keeps the battery warm and amperage up. O'Reilley auto parts has them.
 

chris03kj

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I have an appt tomorrow morning to get the Mopar engine block heater installed on the KJ! :signs1:

It's usually parked outside, I'm wondering those that have them, what temps do you use them at and for how long do you plug in? Here it's going to be about -15F below (lows) for the next few days and usually around 0F for a low. I was thinking about setting the heater on a timer and having it come on for about 2 hours before the KJ gets driven? Is it possible to do overkill?

Thanks!


How much did you get the heater for? And how much is dealer installing for? Also do you know the part number? I park outside at night, and especially this winter has been brutal with starting and in two days our high is -15 degrees so im worried...



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HoosierJeeper

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Got the heater online for like $50, my shop here charged $150 to install it plus HOAT coolant (Zerex G05) top off so for everything I'd count on around $230.
 

Cardhu

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Leaving it plugged in causes no problems. mine is plugged in constant december to march or whenever its below -20 c.

Jeep warms up in less then 10 min as compared to near 20 when its -40 and not plugged in.
 

chris03kj

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Alright thanks, just bought one of those. Do you happen to know where it was installed on your block? I don't want to pay the dealer, as I am more then qualified to do it. do you happen to have a picture of the install location?


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Porkchop

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It should come with instruction but freeze plug behind the motor mount on the passenger side. I don't want to go out in 12” of snow to get pictures. Acutely it's easy to do but HOAT will come out of the freeze plug even after draining the coolant.
 

chris03kj

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Sounds good, I can't wait to brave the -17 degree weather and foot of snow coming for us tomorrow...thanks for your help!


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HoosierJeeper

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Be prepared with the HOAT too...when the coolant drains out, chances are it'll hit the frame or skids so it'll get dirty.
 

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