Starting w/ Block heater Plugged in?

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dashbarron

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I had a '17 and the block heater went bad in 3 years with just winter use. Someone said starting the pickup with the block heater still plugged in could have damaged it. Any truth to this urban legend?

Just always started pickup and then unplugged, capped the block heater, tucked the cords away, etc. Just gave the pickup another minute to move oil around before I took off.
 

zrock

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not going to hurt a thing.. Sometimes they just go bad.. Was it the whole heater or just the cord? Even when i had a diesel i never run a block heater after i switched good oil and a shot of antijell of some sort in the fuel tank and good to go, running a gas engine i have never run a block heater unless your somewhere where it gets down to -40 give or take
 

Elc-1973

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Lived in Fairbanks Alaska and always auto started my truck with it plugged in, along with everyone else and never had any issues, and it’s regularly -40f in the winter. Like said above it has nothing to do with the engine running.
 

BossHogg

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Someone said starting the pickup with the block heater still plugged in could have damaged it. Any truth to this urban legend?
A block heater depends on coolant to absorb the heat it makes, if a block heater is operating without a heat sink source, well, goodbye block heater. If running the engine creates an air pocket around the block heater then it is possible but highly unlikely an air pocket would form.
 

JayLeonard

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The block heater has nothing to do with anything else in the truck. The only danger starting it with it plugged in is the chance you will forget to unplug it and drive off...

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This. I set mine up so I had to walk past the plug and cord to get into my truck. This forced me to unplug it before I opened the door.
 

tjfdesmo

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A block heater depends on coolant to absorb the heat it makes, if a block heater is operating without a heat sink source, well, goodbye block heater. If running the engine creates an air pocket around the block heater then it is possible but highly unlikely an air pocket would form.
This is the root of the old timers' warning. If the block heater has been plugged in long enough and the coolant temp has stabilized there is nothing to gain by keeping it plugged in while starting. I always followed the old timers' rule. YMMV
 

4xdad

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I used to work out of town a lot and we had two small kids my vehicle had to start no matter what when I wasn’t there so I had a block heater and a circulation heater the whole truck could be covered in snow but the hood would be clear it would only have to warm up for a couple of minutes and it would blow heat 84 blazer
 

combatgrunt

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I start mine with it in before I walk outside usually a minute or 2. I also have mine on a timer for the heater got a cheap programmable one works like a charm
 

GTyankee

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I often wondered if Chrysler is using Block Heaters from KAT'S


 

DodgeDude99

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The block heater has nothing to do with anything else in the truck. The only danger starting it with it plugged in is the chance you will forget to unplug it and drive off...

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Guilty! My 2nd gen, had it plugged in at work, left and was driving down the road wondering why the hood was bouncing (my plug was under the hood)
 

crash68

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The RAM block heater doesn’t contact the coolant (at least the newer models). It warms up the block itself.
The gas engine block heaters don't touch the coolant but the diesel engines do
 

howie12

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Some years ago I read a footnote warning in a blockheater manufacturer's catalog. OF course I don't recall the name of the outfit but the warning basically said it was recommended not to start the engine with the block heater plugged in because in certain cases the water flow can cause sufficient turbulence around the block heater element and result in a hot spot and shorten the life of the element.

IT makes good technical/theoretical sense to me. It seems less likely to be a problem at idle when coolant flow rates are low and turbulence is less than compared to roaring the engine upon starting like some people do. Personally I unplug mine.

Now I am also guessing/surmising on issue here. It seems likely that all replacement units are not exactly the same size and shape element as the original and that could be the root cause. Narrow water passages on some engines may make them more susceptible to the issue too. ANyhow, given the lack of a problem by many people that regularly use their block heaters in the winter and regularly start their engines with them still plugged in it seems safe to say it shouldn't be an issue with the original heater in the hemi. Not sure how many Pentastar users there are so it may not be fair to conclude the same for it.

All the best,,

And the above was written before I saw the note that the block heater on the gas engines doesn't go into the water jacket on the gas engines. Is that the Hemi and the Pentastar? Never heard of such a thing from the factory, but I guess it saves a place for a water jacket leak.
 

Dean2

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Any time it drops below freezing, I use the block heater if I have to park outside for some reason. Just that much easier on the vehicle. I have never for a second worried about whether the block heater was unplugged. That had nothing to do with why yours failed. Most common failure is the cord or plug, check it for continuity before going to the trouble of replacing the block heater itself..
 
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