Block Heater Questions

[crobertson1]

I have a few questions about the block heater on our '93. My son usually plugs it in for about a half hour before he leaves for work at 5:40 AM. He says it gets the engine warm enough in that time that the heater warms up and the engine starts easily. He only drives about 10 minutes to work.



Does the block heater cycle if it is plugged in all night, or does it stay on the entire time? Will it get too hot and cause the coolant to evaporate away? I told him he needs to get a timer to plug the extension cord into, so it comes on for an hour or two before he leaves, but he hasn't yet. It's got to be a pain for him to get up and have to go plug it in right when he wakes up.



Thanks.

 

[PToombs]

Not positive, but pretty sure it cycles. Plugging it in for 1/2 an hour is about as good as nothing. When it gets real cold it won't help any. A timer is the hot ticket, set it for an hour or even 2 before he needs to leave. I read someplace that it's better to unplug the timer before it goes off, keeps the contacts from getting burnt as bad.

I've never seen one make the coolant evaporate, and I've been around them for over 20 years.

 

[Midnite]

I'm almost positive the block heater does not cycle. It's nothing more than a heating element and a cord--no relays or any other circuitry that would handle the cycling. I've left mine on for more than 12 hours before and it does no harm whatsoever to the truck--just lots of wasted electricity because the thing pulls 750 watts.



I agree with Pete that half an hour doesn't do much at all. I like to have mine on for at least an hour before I leave, and 2 to 4 hours if temps dip below 0 deg. F.



Mike

 

[crobertson1]

I was surprised when he told me that it seemed to help for a half an hour. It was -10 this morning and supposed to be even colder tonight. I'll tell him to set his alarm for 3:30 to get up and plug it in. :-laf



I think he actually had it plugged in from about 10:30 last night to when he left. I'll suggest the same tonight!

 

[jwinnie]

I agree with Midnite. When I had my '01 I timed it, with the temp about 25deg it took about 4 hours to get the coolant up to 100deg and leveled off there, left it plugged in all night with the same result. Just a bigger electric bill .



There was a post a few years ago by a member who had a backup generator at his work that had been plugged in since about 1986. So I'm pretty sure it won't hurt anything.



I figure if you leave it plugged in overnight it helps the whole engine compartment warm up a bit, batteries, fuel system, etc.



John

 

[MMeier]

Do what I am the next few nights since its going to be around freezing here. Go and park in the empty house next door and plug in there !!! Pretty sure the things do not cycle.

 

[CToney]

I plug mine in overnight all the time. They need 6-8hrs to fully warm the block. you don't want the grid heaters to cycle. If it does fail it is cheap and easy to change. It should cost around eight cents an hour to operate. I put an oil pan heater on as well to improve cold starts and use a winter front. I wish my '03 would warm up like the ole '92 does. after a 5 min warmup and 1 mile drive she's making heat. You have to drive 6 miles with the '03.

 

[Skydiver]

CRobertson1, Be sure to purchase a timer that is heavy duty, rated for 15 amps.

30 minutes does help-laws of physics. BTU's.

Try pointing the front of the truck downwind.

When the temps here get below 25F, I plug in. Sounds like a different truck when I crank it. Just purrs, no skipping or blue smoke.

 

[crobertson1]

Thanks guys. We will get a heavy duty timer for sure. He said it was nice and warm this morning after being plugged in all night. 8 cents an hour is a bargain to have the engine warm immediately!

 

[fkovalski]

Hey, Craig-

You got all the good answers... but I'll add my $. 02 which 'aint worth a dime...

You do not need a "heavy duty" timer as you allude to... most household outlets are only 20A (perhaps 15 on an older one) ... just a regular timer capable of this current will work- the kind with the "programmable pins" rated for 20A is all I use.

But as stated, all night will not hurt it. I used to do it up here that long before I had a garage. For the real cold nights just do an all nighter.

 

[crobertson1]

Thanks Frank . Good to hear from you. Can you tell that I know nothing about electricity? I can't wait for summer so the use of the block heater isn't necessary!



Craig

 

[Greenleaf]

The buses here at the school are plugged most all the time. All day. All night and on weekends as well.

 

[ZedMikey]

I've been tempted to run a long extension cord from my apartment down to the parking lot. :-laf It's been in the teens the past couple night, and my truck has been slow to wake up in the morning. The idle smooths out pretty quick, at least...

 

[SHobbs]

I plug mine 2 hours before I leave for work if I need to. I didn't like the idea of leaving it plugged in all night so I swapped the 750 watt for the 1000 watt. Not that big of a difference but it does get a little warmer than it used to just all depends on how cold it is outside. Funny thing is that the larger element does not make the crackling noise like the smaller one did.

 

[crobertson1]

It's -12 right now and only going to get colder tonight. He's been leaving it plugged from about 10:30 until he leaves at 5:30 AM. I wish I had a block heater for my Cherokee!

 

[Ncostello]

Just go to Napa and they sell an inline heating element for the lower hose. Just cut about 2" out of the hose in a straight section and it has two ends on it. Two clamps and voila! I used one on a F150... and the thing used to work decent. On a very cold night... the hoses and block felt mildly warm. Made startups easier for sure. Or you can remove a freeze plug and get a real one. Most gas pickups can be ordered with them nowadays.



I ordered a new 97 Chevy work truck... well... back in 97 I guess it was. I used to plug it in on that Vortec V6. But it never heated up too well. Still seemed like it took a while to warm up after starting. It was just too small wattage I assume.

 

[JLEONARD]

I used to have mine on a timer that would run the element for about 3 hours prior to my normal departure time.

Unless the temperature was in the single digits or lower it would make the engine warm enough so the grids did not cycle. That's 56 F.

The heater would put out enough at startup to keep freezing rain or snow from being a problem on the windshield.