Block Heaters - What Do They Do?

[ebry710]

I was flip'n through the LMC catalog a saw a block heater for sell. I realize it would be important in minus temperatures, but do they work for temperatures in the 20's.

My truck has a heater only control, which means I do not have A/C to dry the air. Cold damp mornings it takes close to 15 minute to defrost the windshield and get heat to my feet.

1) Does a block heater remedy either or both of these problems?

2) How easy are they to put in?

3) If you buy a new block do you use the old heater or buy a new heater?

[fine69]

Block heaters just keep the coolant from freezing when it sits for prolonged periods(overnight).

Consider it engine insurance.

[Dunenutt]

I never had one on a gas engine. My dodge diesel block heater keeps the motor around 125 F. The engine warms up considerably faster with the heater on.

They usually install in a freeze plug hole. The only diffuculty would be access, and how bad the freeze plug is to get out.

BTW, I notice a difference in the power bill when I use it, so keep that in mind.

[71swb4x4]

I have used them on gasoline engines. They do give you much faster warm up. When I used them I put mine on a timer so it's only on for an hour before I leave.

[GASoline71]

They have nothing to do with keeping coolant from freezing. If you have to use a block heater to keep coolant from freezing... you need to recheck the coolant mix ratio you are using. They do offer easier start ups in extremely cold environments.

Diesels have block warmers to aid in starting in the cold and save wear and tear on the glow plug systems.

I agree with how much power they use to heat up. When I had my diesel trucks and would plug them in overnight to have a nice warm engine for startups in the winter... my power bill went up as well.

Another note... since the engine is warm... it would invite critters to make nests on top of the engine block as well. I had more mouse and rat problems with the truck plugged in during winter, than sitting unplugged during the summer.

Gary

[ebry710]

It sounds like the cost to run is a big issue. I guess it is like turning your truck into an electric water heater.

So you pull out on of one of your freeze plugs and pop it in. Then it plugs into the wall. Which one is better?

Sounds like it would work to get the heater and defroster going in the morning.

[Dark Knight]

Someone posted on here awhile back that there is a little pump that you put inline with your heater hose and it circulates and warms up the coolant. I forgot how hot it gets, but it was more than what a block heater will do. I know you could plug it in, wait a few minutes, turn the fan on, and feel hot air out of the vents all without the truck running.

[GASoline71]

I see the OP lives in Santa Rosa CA... I doubt he will see any benefit from a block heater. Plus gas engines warm up fairly quick compared to diesels.

Install a fan clutch if you want the truck to warm up a little faster in cooler weather.

Gary

[geezer#99]

THere are different kinds. There's a recirculating type that is spliced into your heater hose. No need to put one in the block. If your engine takes that long to warm up you need a higher rated thermostat or flush out your heater core or clean the air inlet around the core.
And like mentioned with the proper coolant mix it won't freeze. It will go to mush.
I changed out a block heater when it was 40 below. Outside on my back under the truck. Pulled the old one out and the coolant mix never drained out a drop. It was just green mush inside. Put new one in. Warmed it up and had it running in 6 cold hours.

[mrein3]

Back in the day - when my 72 Chevelle was my daily driver in the winter (I know I cringe too when I re-read that) I had a heater patched into my heater hose.
It works just like a block heater. There is an element in there that heats up. The whole heat rising/convection thing takes care of the rest. The heat rises (hot coolant rises) and is replaced in the heater with more cold.

Now-a-days I make sure I check the block heater box on all the cars I order. My attached garage is not heated but stays at or around the 32F mark all winter. I still plug in my block heaters on cold mornings. It is just easier on the car and me to get into a car that has heat coming out of the heater core faster than starting with a cold engine.

I probaly keep better track of my electric bill than most folks and still have yet to notice a change caused by my block heaters. Do the math. At best they are 1500 watts. For easy math lets say they are 1000 watts. At 10 cents/kilowatt/hour that is 10 cents every 10 hours at 1000 watts. You plug it in an hour before you leave or set it up on a timer to turn on an hour before work and it will cost you a penny a day.

What else can you do in your car for a penny a day? I guarantee that 110v plug-in is cheaper than $3.299/gallon gas to warm up your engine coolant. Heck! I'm still burning non-oxy premium in my truck that cost me $4.259 to fill up with a few weeks ago.

[68 IRON]

I put mine on a timer. Like everyone else, I would set it to go on 1-2 hours before I would be leaving. Then of course its idle, not pulling any current... it worked great.

[Stocker]

Originally Posted by mrein3

Back in the day - when my 72 Chevelle was my daily driver in the winter (I know I cringe too when I re-read that) I had a heater patched into my heater hose.
It works just like a block heater. There is an element in there that heats up. The whole heat rising/convection thing takes care of the rest. The heat rises (hot coolant rises) and is replaced in the heater with more cold.

When I was in the midwest back in the Seventies, I had a couple rigs that I put lower radiator hose heaters in. They were easy to install & very effective..... worked by convection, just like your heater hose units.

[special-K]

The accessory engine heater was the type you install into the heater hose. As said earlier,they have nothing to do with keeping your engine from freezing. That would be the purpose of anti-freeze. The purpose is easier starts,less cold start wear on engine,and quick heat. The block,coolant,and engine oil all stay warm. So better lubrication is instant and easier on seals. Even in Santa Rosa,if it's taking 15 minutes to get good heat you will benefit. I am curious what thermostat you run.

[72peace]

I installed a block heater on my 72 DD last winter with a "Thermostatically Controlled Outlet" from Amazon it turns on at 20 and off at 30 so it only works when I need it. I love it, I don't have to wait for the heater to warm up, it's hot right when I start the truck.

Cheers,

[Pont406]

My '69 c-10 had one from the factory. Option k05 engine block heater but it was long gone when I got a truck.

[Stocker]

Doesn't seem like it would get cold enough in Santa Rosa to need a block heater. Maybe you just need a good thermostat -- IIRC, my 195* t-stat is stock, and allows a reasonably quick warm-up.

[ebry710]

Originally Posted by Stocker

Doesn't seem like it would get cold enough in Santa Rosa to need a block heater. Maybe you just need a good thermostat -- IIRC, my 195* t-stat is stock, and allows a reasonably quick warm-up.

Unlike LA or even San Francisco, Santa Rosa has been running in the between mid 20's and low 30's in December and January. As a I am a landscaper, I am constantly fighting frozen windshields and fogged windows. I loose 15 minutes a day during this time. Plus I just get cold.

Currently I have a A/C in my other work truck. It removes the water from my cab. One time my A/C went out and I was in a hurry. I spent of that fifteen minutes with the window down and a towel wiping the inside window.

When it stays below 20, the air becomes crisp and dry. When the weather bounces below freezing to above dew point, humidity is king. Without dry heat from your engine, there isn't a way of getting the water to dissipate.

[Stocker]

Originally Posted by ebry710

Santa Rosa has been running in the between mid 20's and low 30's in December and January.

I didn't realize that it got that cold there....

Dunno how much trouble it is to install block heaters, but as I posted above, lower radiator hose heaters worked very well for me (at temps in the teens and lower) and are easy to install.

[ebry710]

Those lower hose heaters, how do they work?

It would seem that the water pump doesn't open until the engine is fluid is warm. I see they are much simpler to install, but does the lower heater still warm the engine water?

[DeadheadNM]

Here's a NOS block heater for my K20 rebuild courtesy of a fellow board member. At a mile in elevation it gets cold here in Albuquerque.

[Keith Seymore]

Originally Posted by DeadheadNM

Here's a NOS block heater for my K20 rebuild courtesy of a fellow board member. At a mile in elevation it gets cold here in Albuquerque.

In the assembly plant, we used to use them to heat our water for coffee, too...



K

[Sequoyah]

I'm going to put one in my 292 when it's rebuilt. On those cold mornings I would rather have it than not.

[passthebuck]

When it starts hitting -30F all the way to -40F, they are essential or that motor isnt starting until spring.

Whenever I put a motor in, I install 2 - one on each side of the block. That is because they dont fail when it's nice & warm when you are in the mood to change one, they always fail when it's brutally cold & that way when they do fail, just cut the ziptie holding the cord on the good one & worry about the dead one in the spring.

[special-K]

My old K/20 Highlander was from Wyoming and had the block heater. I kept the plug stuffed into the back of the bumper guard:

[magicoolbus]

A friend of mine is a bush pilot in Alaska, here's how he manages sub zero temps: Most if not all piston powered airplane engines have a quick oil drain. Upon shut down, he would drain his oil into a covered pail and bring the oil into the house with him. When he went out to fly the next morning, he would add the 'warmed' oil back into the crankcase, taking the chill off the engine and speeding up warm up. Might not be applicable here, but is definitely an interesting approach!