How long to warm up with block heater
11-28-2010, 07:22 PM
#16
Registered User
And as jrs_dodge_diesel replied, the block heater is not thermostatically controlled. When its on, its on.
11-28-2010, 11:47 PM
#17
Registered User
11-28-2010, 11:53 PM
#18
Registered User
The IAT (Intake Air Temperature) sensor is one of the triggers for cycling the grid heaters after starting. The block heater warms up the engine, and also the intake (and IAT sensor) enough to not need the grid heaters before starting. Which is why you only only get a 2 second WTS light.
After starting is different because now you are pulling cold air through the intake and the IAT senses that and signals the ECM. THe ECM checks a few other things (coolant temp, and vehicle speed), and determines whether or not to cycle the grid heaters for assisting with engine warm up. This is why the grids can cycle after warmup, even though they were not used for starting.
Once the coolant reaches 140ºF, or truck speed reaches 20-25 MPH, the ECM stops cycling the grid heaters.
As far as the block heater cycling, unless it was modified, it never cycles. There is no thermostat to control the block heater, it is wired straight to the plug. So if it is plugged in, it's on the entire time.
After starting is different because now you are pulling cold air through the intake and the IAT senses that and signals the ECM. THe ECM checks a few other things (coolant temp, and vehicle speed), and determines whether or not to cycle the grid heaters for assisting with engine warm up. This is why the grids can cycle after warmup, even though they were not used for starting.
Once the coolant reaches 140ºF, or truck speed reaches 20-25 MPH, the ECM stops cycling the grid heaters.
As far as the block heater cycling, unless it was modified, it never cycles. There is no thermostat to control the block heater, it is wired straight to the plug. So if it is plugged in, it's on the entire time.
11-29-2010, 12:07 AM
#19
Registered User
i checked my manual, and it says nothing about being regulated, so i suppose the volume of coolant in the system would prevent it from boiling ......i'll check the temperature in the morning......... it's been plugged in for 3 days so it should be pretty warm
11-29-2010, 03:32 AM
#20
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11-29-2010, 11:33 AM
#21
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i checked it this morning and the coolant was 51 degrees.so it must cycle
11-29-2010, 01:21 PM
#22
It doesn't cycle...if you replace one you will see that all it is comprised of is a heating element and a power cord, there is no thermostat or switch of any kind on it. My guess is the heat loss from the block and radiator plus the amount of coolant keeps it from overheating.
I use one of these bad boys instead of a timer on mine http://store.dieseltruckresource.com/blheco.html I love that I can leave my truck plugged in ALL the time and it ONLY operates when needed so my truck is ready to go 24 hours a day
Unlike a timer that will cycle daily, I can leave this thing plugged in for months and it only cycles as needed by the actual air temp rather than a timer.
I use one of these bad boys instead of a timer on mine http://store.dieseltruckresource.com/blheco.html I love that I can leave my truck plugged in ALL the time and it ONLY operates when needed so my truck is ready to go 24 hours a day
Unlike a timer that will cycle daily, I can leave this thing plugged in for months and it only cycles as needed by the actual air temp rather than a timer.
11-29-2010, 07:54 PM
#23
I think we need do get on the same page when we are talking what is cycling!
I'm talking the intake manifold grid heater when it's 20 degrees out and the truck has been plugged in all night. I still believe that the "grid heater" comes on when you first turn on the ignition switch. in this situation.
I'm talking the intake manifold grid heater when it's 20 degrees out and the truck has been plugged in all night. I still believe that the "grid heater" comes on when you first turn on the ignition switch. in this situation.
11-29-2010, 08:18 PM
#24
Registered User
I think we need do get on the same page when we are talking what is cycling!
I'm talking the intake manifold grid heater when it's 20 degrees out and the truck has been plugged in all night. I still believe that the "grid heater" comes on when you first turn on the ignition switch. in this situation.
I'm talking the intake manifold grid heater when it's 20 degrees out and the truck has been plugged in all night. I still believe that the "grid heater" comes on when you first turn on the ignition switch. in this situation.
11-29-2010, 08:19 PM
#25
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I think we need do get on the same page when we are talking what is cycling!
I'm talking the intake manifold grid heater when it's 20 degrees out and the truck has been plugged in all night. I still believe that the "grid heater" comes on when you first turn on the ignition switch. in this situation.
I'm talking the intake manifold grid heater when it's 20 degrees out and the truck has been plugged in all night. I still believe that the "grid heater" comes on when you first turn on the ignition switch. in this situation.
12-02-2010, 11:03 PM
#26
Registered User
Thread Starter
Sorry I didn't update my signature.
I am indeed no longer in burbank, I am near Salt lake City, UT.
I ended up getting new batteries last week anyway....I forgot to leave the heaters on one time before starting and it would only "click" so that was the end of it. When I need to get to work,..I need to get to work. I had them do an amp test on the batts and they were only about 30 percent power. Luckily they were partially under warranty so the new ones were about $35 each due to being pro-rated.
Even when my block heater is on all night, it has always cycled the intake heater anyway when I start it. The voltmeter goes up and few seconds, then down....up until I hit about 20 miles per hour....After than they must automatically turn off or something because it then just sits and a little over fourteen volts and stays there.
I am indeed no longer in burbank, I am near Salt lake City, UT.
I ended up getting new batteries last week anyway....I forgot to leave the heaters on one time before starting and it would only "click" so that was the end of it. When I need to get to work,..I need to get to work. I had them do an amp test on the batts and they were only about 30 percent power. Luckily they were partially under warranty so the new ones were about $35 each due to being pro-rated.
Even when my block heater is on all night, it has always cycled the intake heater anyway when I start it. The voltmeter goes up and few seconds, then down....up until I hit about 20 miles per hour....After than they must automatically turn off or something because it then just sits and a little over fourteen volts and stays there.
12-03-2010, 09:46 AM
#27
Sorry I didn't update my signature.
I am indeed no longer in burbank, I am near Salt lake City, UT.
I ended up getting new batteries last week anyway....I forgot to leave the heaters on one time before starting and it would only "click" so that was the end of it. When I need to get to work,..I need to get to work. I had them do an amp test on the batts and they were only about 30 percent power. Luckily they were partially under warranty so the new ones were about $35 each due to being pro-rated.
Even when my block heater is on all night, it has always cycled the intake heater anyway when I start it. The voltmeter goes up and few seconds, then down....up until I hit about 20 miles per hour....After than they must automatically turn off or something because it then just sits and a little over fourteen volts and stays there.
I am indeed no longer in burbank, I am near Salt lake City, UT.
I ended up getting new batteries last week anyway....I forgot to leave the heaters on one time before starting and it would only "click" so that was the end of it. When I need to get to work,..I need to get to work. I had them do an amp test on the batts and they were only about 30 percent power. Luckily they were partially under warranty so the new ones were about $35 each due to being pro-rated.
Even when my block heater is on all night, it has always cycled the intake heater anyway when I start it. The voltmeter goes up and few seconds, then down....up until I hit about 20 miles per hour....After than they must automatically turn off or something because it then just sits and a little over fourteen volts and stays there.
The intake heater grid will cycle till the engine gets up to temp. It's designed to help emissions as well by getting the engine up to operating temp. faster.
12-03-2010, 10:34 AM
#28
Registered User
Even when my block heater is on all night, it has always cycled the intake heater anyway when I start it. The voltmeter goes up and few seconds, then down....up until I hit about 20 miles per hour....After than they must automatically turn off or something because it then just sits and a little over fourteen volts and stays there.
12-03-2010, 12:01 PM
#29
However, in addition to the block heater I also have a pad heater on the oil pan, so that may be making a slight difference in the intake temp. the ECM sees.
There are probably a number of other factors which affect the intake manifold temp while the engine is plugged in, like what kind (if any) of radiator/grill block-off is in place, whether the truck has open wheel wells, or if it has the plastic covers in there, and of course if there's any wind.
12-06-2010, 06:55 PM
#30
Administrator
750 Watts = 2559 BTU's
The smallest burner on my gas stove puts out 5000 BTU's (about 1,465 Watts).
That small 750 Watt block heater gets to heat up 6 gallons of coolant, plus 900 lbs of cast iron. That is why the coolant does not boil. Just enough of a heater to get it warm, but nowhere nearly enough power to get any coolant boiling. Another factor here is that the coolant circulates in the block due to natural convection when the heater is on too.
Midnite, you are correct, there are a number of other variables and environmental factors at play in how well the block heater warms up the engine and affects the grid heaters.