Block heater ?

[CBrabec]

This may sound odd, but is there a temperature at which plugging in my truck at night won't do me any good? The reason I ask is because I had replaced my block heater last year. But earlier this week, I had the truck plugged in over night, (wind chills were -35) and i went to start the truck in the morning, and the 'wait to start' light stayed on for about 20 seconds and then I started the truck. But this morning the wind chill was (0) and the light only stayed on for a few seconds. When the temps get that cold, does it do me any good to even plug it in? Just wondering.

 

[E2360]

I plug mine in at anything below 32. As a note, the wind chill has no effect on inanimate objects; only applies to living things. Hope this helps.

 

[DonFitzwater]

E2360, you are correct in saying that wind chill has no effect on objects, however, wind speed does. If your truck is plugged in at 0 degrees with no wind, heat will rise from the cylinder head area and warm the air passages where your IAT sensor is located. This will decrease or eliminate the on time for your intake heaters. If the wind is blowing, heat will be removed and there will be a decrease in IAT temp that the computer sees and will increase your intake heater on time.



Crabec, makes sure that your block heater is actually working. Plug it in and listen for a hissing/sizzling sound. If you can get your hands on a temp gun, take a temp reading at the block heater and see if it is working or not.

 

[WCPoe]

Crabec, makes sure that your block heater is actually working. Plug it in and listen for a hissing/sizzling sound. If you can get your hands on a temp gun, take a temp reading at the block heater and see if it is working or not.

I agree with listening for the sizzling sound. If you don't hear it I would investigate further. If I plug in, the head/water temps are usually 120-130F on my Juice monitor when I start up.

I don't recall the wait to start light coming on when plugged in but I live in a warmer climate rarely requiring the block heater so someone else may have to comment on this.

 

[JJPage]

This may sound odd, but is there a temperature at which plugging in my truck at night won't do me any good? The reason I ask is because I had replaced my block heater last year. But earlier this week, I had the truck plugged in over night, (wind chills were -35) and i went to start the truck in the morning, and the 'wait to start' light stayed on for about 20 seconds and then I started the truck. But this morning the wind chill was (0) and the light only stayed on for a few seconds. When the temps get that cold, does it do me any good to even plug it in? Just wondering.

I believe your truck is perfectly normal, mine behaves exactly the same.



The block heater and the grid heater(s) are two totally separate systems, my grids come on in the middle of summer, sometimes in the morning.



You can check your block heater, connect it to a cheap extension cord, split the extension cord with a knife (unplugged) so you can put a clamp on amp meter around the hot/black conductor. Now plug it in, you should be able to see an amp draw, not sure but I think they are 1000w heaters, you should see about 8 amps.



Jess

 

[CToney]

Block heater is 750 w. I plug mine in any time it is around freezing out. Less warm up time and your engine will last longer. I even run an oil pan heater too. These trucks don't really warm up until you get them moving. My wait to start worm will come on but often the grid heaters won't cycle. It is close to 40 below here today with the wind chill.

 

[CBrabec]

I know the block heater is working because when I plug it in, I see the lights in the garage slightly dim, and then get brighter when unplugged. I don't here a sizzling sound though. This morning was 2* with a wind chill of -10 and no problems.

 

[Wingate]

Block heaters will help if you live in a cold climate and don't want to wait forever to get some heat in the block before you put a load on it. . I have worked on some big Cats that have adjustable temp. heaters on them that keep the coolant temp at 180 degrees all the time, (stand-by generators) I live in E. Texas, so to be honest, i've never plugged my truck in. On our cold days, I just start it, put it at 1200rpm and go back in the house.

I see you live in Nebraska, so the block heater probably helps you get it warmed up sooner. The good thing is that it helps warm your engine oil up quicker.

 

[rbattelle]

Plug it in and listen for a hissing/sizzling sound.

This is not a good indicator of a functional block heater. A better way is to measure resistance across it - should be ~18 ohm. My block heater functions perfectly and is silent. [It used to sizzle, but then one day it just stopped... I hope it doesn't have mineral deposits on it].

I think they are 1000w heaters

Unfortunately, they're only 850 watt.

I don't here a sizzling sound though.

See my comment above. I've heard 2nd gen owners occasionally comment that their block heater is silent too.



Ryan

 

[CBrabec]

Well, my truck has been sitting for a day now plugged in with the air temps being below 0. I will see how long the light stays on in the morning when I get ready to go to work. Its supposed to be -10 to -15 tonight with wind chills between -35 to -40. When my old block heater stopped working last year, the start ups would be harder and the truck ran rougher. Since i replaced the heater and cord, even though my light stays on for a bit, the truck starts up fine and runs smooth. I'm probably worring about nothing. I just find it wierd that at times the truck stays plugged in for 8-10 hours and the light stays on for a few seconds, but when the truck sits for a day or more plugged in, it takes the light 15-25 seconds to shut off. The only time I expierence this is when the temps are this extreme.

 

[bheiting]

I live in Minnesota and have never used the block heater. What I prefer is

a magnetic heater attached to the end of a 1X2. I reach under and slap

this on the oil pan. My theory is you want warm, thin oil circulating as

soon as the truck starts. That's when most wear occurs. I guess you

could use it with the block heater for better results, but warm oil is my

main consideration. The magnetic heater doesn't seem to affect the intake

heater either.

 

[JimB1]

I believe your truck is perfectly normal, mine behaves exactly the same.



The block heater and the grid heater(s) are two totally separate systems, my grids come on in the middle of summer, sometimes in the morning.



You can check your block heater, connect it to a cheap extension cord, split the extension cord with a knife (unplugged) so you can put a clamp on amp meter around the hot/black conductor. Now plug it in, you should be able to see an amp draw, not sure but I think they are 1000w heaters, you should see about 8 amps.



Jess

If you don't have clamp on ammeter, you can splice one of those pig tail rubber light bulb sockets IN SERIES with one of the extension cord leads.



Use largest wattage light bulb handily available 'cuz it'll come on pretty dim due to heater element larger resistance dropping about 7/8 of the voltage but any light bulb glow at all means current is also flowing thru heater element.

 

[ACamilli]

My 06 with it's 750 watt heater doesn't get as warm as my 1999 did with it's 900 watt heater. I could hear the 900 watt cook, but not the 750 watt. Yes it does work, just not as well.

 

[CToney]

I believe they are all 750 watt heaters stock. My wait to start light stays on even though the grid heater doesn't cycle. Watch your volt meter if it drops below 12v your grids are on. Running the block heater is probably better for the engine than an oil pan heater as you want the heat in the head to help atomize fuel as opposed to washing down the cylinder walls. Anyone who has torn apart a V8 will notice more wear on the side where there is no block heater. I use 0w40 oil with an oil pan heater and a block heater. I have oil pressure right away and my grids hardly cycle. My batteries, starter, and alternator should last longer.

 

[BK]

I have a 99, I thought I read they were 650watts. But could be wrong.



I measured mine and it came in at 675 watts with a watt meter. The watt meter has some losses the way it's wired up.



Due to bad cords and plugs, and not having the heater work at times, after I put the widget (or what ever it's called) in from Genos, I finally put some remote monitoring in on mine. I have a couple of transformers wired up for voltage and current that are monitored by a DAQ. The DAQ basically goes into my network at home, and software on my PC talks to the DAQ of the network so I can see what's up.

Right now mine is plugged in and warming up, and there is 119. 7Vac rms applied, and it's drawing 5. 74A.

That's 687 watts being consumed.



I haven't have gone as far as putting a thermal couple on the manifold yet. . but I've been tempted. my daq does temperature as well. Right now I'm just measuring the outside temps to figure if I want to turn on the heater or not. I have an X10 module to turn it on remotely from my desk.



I generally do when it gets below 40. Admittedly it seems marginal , but at 32 and below, yea, it makes a nice difference.



I haven't measured the resistance of mine, but ohm's law says its roughly 20ohms. With figuring in a 25ft extension cord and connection resistance, real close to rbattelle 18Ohms.



At 18ohms, with 120Vac, that would yeild 799. 99 watts.



But we all have more resistance in there than the pure heater resistance. Plugs, lenghts of extentsion cords, outlets... ... ... as we add these parastic losses (increase resistance) the current drawn goes down, so the wattage / heat goes down.

Hence my ~685 watts being drawn.



If the available voltage is lower in your house, that too lowers the current drawn, and so the wattage / heat is reduced.

 

[rbattelle]

Watch your volt meter if it drops below 12v your grids are on.

That's not quite accurate. The ECM depresses the needle on the voltage gauge during a postheat cycle, whether the heaters actually warm up or not. A depressed needle in and of itself is not an indication of functional heater grids.



Ryan

 

[JimB1]

BK, Since you're taking a analytical measure, I would guess that inductive reactance (transformer effect) within the heater element spiral winding accounts for your lower measured true power consumption 687 watts then what the measured dc resistance of 18 ohms and calculation 799 watts suggests.



Classic example of incorrectly applying dc resistve circuit analysis into ac resistive/inductive circuit.



If all house wiring, plugs, cords, are anywhere close to good, they shouldn't account for more than 2-3 ohms resistance or about 5 watts max lose.



Given, the heater element's primary design is resistive heating in nature, but the closeness of element spiral winding, I believe results in some inductive reactance coupling between spiral windings (transformer effect) to current.



Similiar classic example of mixing dc & ac thinking is standard light bulb filament analysis.



Measure its resistance with ohmmeter, which is dc, and 100W bulb is about 10 ohms.



Plug 10 ohms resistance into Ohm's Law gives about 12 amps calculated for light bulb draw which is wrong because the true measured current draw is about . 8 amp for 100w bulb and there-in is the anomaly from mixing dc & ac analysis.



So true measured . 8 amp draw gives the 100 watt bulb filament Inductive Reactace of about 150 calculated ohms as compared to ohmmeter measure of 10 ohms.



You can never measure a Inductive ohm and/or Capacitive ohm, they can only be calculated using other true circuit measurements.



Anyhow, incorrectly mixing AC & DC analysis is where discrepancies turn up.



They can be properly analyized & calculated in combination with Vector Algebra.



So, given measured 119. 7 volts and 5. 74 amps, all rms, and all the line loses shouldn't exceed 5 watts, your 687 watts is true world heating from block heater element.

 

[BK]

JimB1,

What your referring to is called Power Factory (PF), the relation ship between real power and apparent power.



What your thinking about is phase angle , that is effected by the major character of the circuit, inductive, resistive, or capacitive.



(and the light bulb goes through more changes in it's characteristics due to the heat, different cold than when hot at it's rated working voltage. )



Unfortunately I don't have anything in my stock pile at home to measure PF or inductance directly.



Actually, during inductor designs we use to calculate the " reactance " , of the inductor... . the inductive (or capacitive) resistance in an AC circuit.

So one can calculate the AC resistance of an inductor.

(and we had instruments that could measure it at predefined frequencies and levels)

For DC, it's just the resistance of the wire.

The greater the frequency of the AC , the greater the reactance becomes a character in the AC ckt, for our discussion.

I don't think there's much actual inductance in the coil of wire in our heater blocks. As well, there's no core either (such as gaped ferrite, powered iron or coolmu).



BUT, one of my watt meters measures apparent power and current.

Current is measured despite PF or phase angle (used for real power calculations-the power that causes heating).

The wattage measured by that watt meter is effected by the PF, it's called apparent power.



The different between the two is the PF in %.



The closer to unity the PF is, the closer the apparent power and real power are to each other.



On my watt meter, they are within watts of each other, leading me to believe the inductive properties of the heater aren't effecting PF at all and are within measurement error.

As stated earlier, from practical experience, I would hazard a guess, there is very little inductance in the heater coil that would have any major effects at 60hz.



Based on that and some reality based intuition to how much resistance is in each connection in my circuit, if I measure the resistance of my total circuit, I'll bet I'll come up real close to the 20ohms. Next time I'm in the basement, and hopefully remember, I'll give it a test.

 

[steved]

As a note, the wind chill has no effect on inanimate objects; only applies to living things.

Wind does have an effect... otherwise our radiators would be useless...

Heat is radiated, and wind strips that radiated heat... molecules in rapid movement (from heat) try to reach a steady state (ambient temperature) and therefore will migrate (transfer heat) to the colder portions faster in order to reach that steady state of ambient temperature. What it is different from "wind chill" is that a unheated object will not get colder than ambient temperatures, but a heated object will lose heat faster because of wind to achieve that ambient temperature.

There is a point at which you would actually cool the block as fast as the block heater can warm it... I have no idea what temperature that would be... cold.

I have noticed that my truck doesn't warm up nearly as well if there is much wind... I believe it blows the residual heat away from the block (keeps it from building up under the hood). I get the same effect... even with the block heater plugged in, the WTS light still stays on (when its really cold or really windy). A set of winter fronts does help a bit with the wind problem, keeps the heat under hood a little better.

And to add, I measured both my dad's 99 and my 04. 5 block heater draw... the 99 indicated 500 watts and the 04. 5 indicated 625 watts... which is obviously a lot less than advertised.

 

[BK]

SteveD,

I've noticed the same thing has you when it's damn windy out, cold, and I go in and wait for the heater wait light to go out.



as far as the 99 heater...

I assume your using the same outlet and extenstion cord when you measure the current draw as the 04?

Is the plug on the 99 in good shape?

I've gone thru one already on my 99, it got hotter then heck and either didn't make a good connection, or I only drew ~3. 5amp, or more wiggeling got it to near 5amps.

It was a fire on my bumper waiting to happen. Finally replaced it. And it prompted me to start using a wattmeter on mine all the time. got tired of running to the basement to check it, so rigged up some branch ckt monitoring to my PC.