Question: Engine block heater cord location
- Thread starter justlkn
- Start date
Yep, thus minimizing the time the engine is running on thick oil that doesn't flow very well. But I believe the oil itself will warm up too.
Heat is conducted from the coolant to the metal engine block (and the heads, via convection as well). Metal is an excellent conductor of heat, and even though the oil pan gasket might be considered a thermal insulator of sorts, the oil pan is held tightly to the block, which allows heat to cross this barrier fairly easily. Also, the engine oil cooler is an engine coolant-to-engine oil heat exchanger, so the heat in the block-heater-warmed coolant has another path (made of highly conductive metal) to the oil that way.
Bottom line: IF the engine block heater is on long enough to reach thermal equilibrium, the temperature of oil in the pan will increase too.
And as was already pointed out, if the coolant is already warm, the oil will be very quickly warmed up much more quickly once the engine starts.
While more effective glow plugs undoubtedly do allow starting in colder temps, the point is not just whether or not the engine will start, but how much cumulative cold-start wear is occurring in repeated cold starts.
Another option for better protection in cold weather (and under other conditions too) is synthetic oil. The rule of thumb is that most wear happens on cold start, and synthetic oil has a clear advantage over conventional oil in cold weather.
Assuming that you don't have some pesky government-mandated post-injection events washing excess fuel into the engine oil, which might make it prudent to change the oil more frequently, synthetic oil is a good option, IMO.
Since the temperature outside is close to -10°F, I think I'm going to conduct an experiment tonight...
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Edit: replaced the some occurrences of the word "aluminum" with the word "metal"
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I wish I had a scientific answer for this argument...Alas, I don't. If I don't plug my truck in for a 0-25 deg start it sounds like hell and it makes me cringe listening to it idle like that. I'm no engineer but that CAN'T BE GOOD! If I plug it in, she fires bright eyed bushy tailed and ready to freaking excel. No experiment needed.
This is for the other DMax van owners out there (both of them
):On page 3-26 of the 2010 van owner's guide:
"The cord for the engine coolant heater is located on the driver side of the engine compartment and is attached to the hose for the power steering reservoir." but on the previous page it says: "...see the Duramax supplement for more information."
So, I found this on page 2-11 of the 2010 van DMax supplement:
"The cord is located in the engine compartment, on the passenger's side of the engine, near the right side auxiliary battery."
Neither of these was correct in the case of my 2010 LMM van.
The first photo below shows where I finally found it. It was taken after I had already pulled it out from where it was stowed
(beneath & behind that cable bundle, held in place by that black zip tie which I put back roughly where it originally was for the photo).
So, on a 2010 LMM van, look behind the air filter indicator ("15762327"), under & behind the main cable bundle, almost in the center of the vehicle.
Yep, my bad. I was thinking of most modern automotive engines in general when I wrote that, but cast iron conducts heat well too.
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Does the oem block [coolant] heater heat the oil too?
But as for 'no experiment needed,' let's find out just how much difference it makes:
The first three of the photos posted below are the display of an infra-red thermometer
Now admittedly this isn't the ideal tool to measure temperatures this cold.
The one I have has an operating temperature range of: 0 to 50ºC (32ºF to 122ºF)
and a measurement range of: -35 to 365ºC (-31ºF to 689ºF)
and the accuracy is not the greatest either:
Tobj= 15 to 35ºC, Tamb=25ºC: +/- 1.5ºC (2.7ºF)
Tobj= -35 to 0ºC: +/-2.5ºC (4.5ºF)
Since I was below the operating temp range, I was only able to use it for a few minutes before I started getting error messages.
Ideally, accurate measurement of temps this low would be done with something like this instead:
But even this is rated at +/-1.0ºC at low temps, and I didn't have one of these handy, so I used the IR thermometer.
Note: The vehicle had been parked for several days prior, so there was no chance of any residual engine heat.
1. Baseline temp of the pile of snow on the vehicle exterior at 12:38AM: -6.0ºF
2. Temperature of concrete pavement under the van: +14.0ºF/+14.5ºF (which may explain why the bottom of the oil pan was slightly warmer than the ambient air temp)
3. Temperature on the underside of the aluminum upper oil pan: -2.5ºF / -2.0ºF
4. Temperature of the stamped steel lower oil pan: not measured
5. Corroboration of outdoor air temperature (taken from the LaCrosse weather station at 1:34AM): -8.1ºF
The engine block heater was turned on around 1:00AM.
The oem cord on my block heater does not have the thermostat that turns on only at temps below 0ºF.
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Update, almost 6 hours later (measurements taken 7:23 to 7:25 AM):
1. Baseline temp of the pile of snow on the vehicle exterior: not measured
2. Temperature of concrete pavement under the van: not measured
3. Temperature on the underside of the aluminum upper oil pan: +31.0ºF / +31.5ºF
4. Temperature of the stamped steel lower oil pan: +8.0ºF / +8.5ºF / +9.0ºF
5. Outdoor air temperature (from the weather station): -4.xºF
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OK, so now we know that the oem coolant heater will heat up the entire engine, including the oil pan (and presumably the oil in it).
But what I had failed to consider earlier is the fact that the DMax has a two-piece oil pan, which can be seen clearly in the photo below.
The lower section is made of thin sheet metal, which provides less thermal conductivity than the cast aluminum upper section, and there's another gasket too, creating another thermal barrier.
When I took the initial measurements, I did not slide back far enough to get a good measurement off of the lower pan (and getting an in-focus photos of the temps displayed on the IR thermometer was even more difficult).
But since the vehicle had been parked for several days, and with no heat being applied, the temp of the lower pan probably was pretty close to the temp of the upper section.
If so, then even the bottom of the lower oil pan was heated up slightly by the engine block heater.
More importantly, the oil pump was probably warmed to at least the temp. of the lower oil pan section (if not higher), because it is bolted to the front of the block:
And the temperature of the oil pickup was probably somewhere in between.
Motor oil has less than one-fourth the thermal conductivity of water, so I guess the oil near the pickup might be significantly warmer than the outside of the oil pan.
And not all the oil in the engine is sitting in the sump, correct? The anti-drainback valve keeps some of the oil in the galleries above the oil filter, and that oil must be pretty close to the (much warmer) temperature of the engine coolant.
An oil temperature sensor that will register temperatures in this very low temp. range (and I would guess that most oil temp. gauges do not go anywhere near that low) would be the better, of course. Admittedly, the measurements I was able to take were less than optimal. But I think it's clear from the measurements I was able to take that the engine block heater does help heat the engine oil too.
True. Starting a warm engine results in less cold start wear, a condition that you can actually hear happening.
But as for 'no experiment needed,' let's find out just how much difference it makes:
The first three of the photos posted below are the display of an infra-red thermometer
Now admittedly this isn't the ideal tool to measure temperatures this cold.
The one I have has an operating temperature range of: 0 to 50ºC (32ºF to 122ºF)
and a measurement range of: -35 to 365ºC (-31ºF to 689ºF)
and the accuracy is not the greatest either:
Tobj= 15 to 35ºC, Tamb=25ºC: +/- 1.5ºC (2.7ºF)
Tobj= -35 to 0ºC: +/-2.5ºC (4.5ºF)
Since I was below the operating temp range, I was only able to use it for a few minutes before I started getting error messages.
Ideally, accurate measurement of temps this low would be done with something like this instead:
But even this is rated at +/-1.0ºC at low temps, and I didn't have one of these handy, so I used the IR thermometer.
Note: The vehicle had been parked for several days prior, so there was no chance of any residual engine heat.
1. Baseline temp of the pile of snow on the vehicle exterior at 12:38AM: -6.0ºF
2. Temperature of concrete pavement under the van: +14.0ºF/+14.5ºF (which may explain why the bottom of the oil pan was slightly warmer than the ambient air temp)
3. Temperature on the underside of the aluminum upper oil pan: -2.5ºF / -2.0ºF
4. Temperature of the stamped steel lower oil pan: not measured
5. Corroboration of outdoor air temperature (taken from the LaCrosse weather station at 1:34AM): -8.1ºF
The engine block heater was turned on around 1:00AM.
The oem cord on my block heater does not have the thermostat that turns on only at temps below 0ºF.
----------------------
Update, almost 6 hours later (measurements taken 7:23 to 7:25 AM):
1. Baseline temp of the pile of snow on the vehicle exterior: not measured
2. Temperature of concrete pavement under the van: not measured
3. Temperature on the underside of the aluminum upper oil pan: +31.0ºF / +31.5ºF
4. Temperature of the stamped steel lower oil pan: +8.0ºF / +8.5ºF / +9.0ºF
5. Outdoor air temperature (from the weather station): -4.xºF
----------------------
OK, so now we know that the oem coolant heater will heat up the entire engine, including the oil pan (and presumably the oil in it).
But what I had failed to consider earlier is the fact that the DMax has a two-piece oil pan, which can be seen clearly in the photo below.
The lower section is made of thin sheet metal, which provides less thermal conductivity than the cast aluminum upper section, and there's another gasket too, creating another thermal barrier.
When I took the initial measurements, I did not slide back far enough to get a good measurement off of the lower pan (and getting an in-focus photos of the temps displayed on the IR thermometer was even more difficult).
But since the vehicle had been parked for several days, and with no heat being applied, the temp of the lower pan probably was pretty close to the temp of the upper section.
If so, then even the bottom of the lower oil pan was heated up slightly by the engine block heater.
More importantly, the oil pump was probably warmed to at least the temp. of the lower oil pan section (if not higher), because it is bolted to the front of the block:
And the temperature of the oil pickup was probably somewhere in between.
Motor oil has less than one-fourth the thermal conductivity of water, so I guess the oil near the pickup might be significantly warmer than the outside of the oil pan.
And not all the oil in the engine is sitting in the sump, correct? The anti-drainback valve keeps some of the oil in the galleries above the oil filter, and that oil must be pretty close to the (much warmer) temperature of the engine coolant.
An oil temperature sensor that will register temperatures in this very low temp. range (and I would guess that most oil temp. gauges do not go anywhere near that low) would be the better, of course. Admittedly, the measurements I was able to take were less than optimal. But I think it's clear from the measurements I was able to take that the engine block heater does help heat the engine oil too.
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Very interesting. We have had some very cold temps and I have been plugging my truck in at home and work. BIG difference in the starting. Plus with the high idle module that I bought from PPE, things are good and warm before take-off!:thumb:
Yep. ...a big difference that translates into less cold-start wear. Seems to me that in all but the coldest climates, there's no need for an oil pan heater. Synthetic oil would be a better (and easier) next step.
While I'd have preferred better measurements (next time I'll see what the coolant temp gauge reads when I unplug it), everyone's anecdotal experience corroborates what the measurements suggest: the block heater heats up the entire engine if plugged in long enough.
And for whatever it does cost in electricity (which in my case is dirt cheap in the winter: only about $0.05/kW-hr), some of that will be offset by eliminating the idling time before you actually drive off, not to mention saving the time waiting for it to warm up. Seems worthwhile to me, if there's an easy way to plug in.
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Haha. Anyone that says a block heater isn't needed I completely disagree. All my bobcats, backhoes, trucks all get plugged in if possible. It helps hands down. Hell half the winter I'd be off work, because machines won't start if there not plugged in.
Sure they will start sometimes, but if plugged in they will start every time. Take your truck and don't plug it in for a week in 0 to -10 temps, don't start it till weeks over. And report back. Then see what happens when it's plugged in.
If they don't sit in a garage, they will start hard when not plugged in. Mine sits in a heated garage so I don't plug it in. Anywhere else, I plug it in. It definitely helps.
Sure they will start sometimes, but if plugged in they will start every time. Take your truck and don't plug it in for a week in 0 to -10 temps, don't start it till weeks over. And report back. Then see what happens when it's plugged in.
If they don't sit in a garage, they will start hard when not plugged in. Mine sits in a heated garage so I don't plug it in. Anywhere else, I plug it in. It definitely helps.
Block Heater
I looked for this for a good while and I found it coming up the back side of the black shield that covers the battery cable. It was tucked in and tied behind the cable against the wheel well cover down under and slightly in front of the battery. Could hardly tell it was there. I have never had an issue with it starting no matter how cold it is but warming up quickly has to be a plus for the engine and its overall economy..
I looked for this for a good while and I found it coming up the back side of the black shield that covers the battery cable. It was tucked in and tied behind the cable against the wheel well cover down under and slightly in front of the battery. Could hardly tell it was there. I have never had an issue with it starting no matter how cold it is but warming up quickly has to be a plus for the engine and its overall economy..
Glad to help out.
And if anyone else needs any further corroboration, here it is:
http://www.youtube.com/watch?v=fC0yD3WA-3Y
OAT was between 4°F to 10°F (not as nearly as cold as some people have to deal with, but you should still get a ~90°F temp rise). The vehicle had been parked for several days before this video, and low temps the night before were in the low single digits F. The block heater was on for 4 hours. Notice what didn't come on? The glow plug light.
One difference compared to most other DMax owners: this is a van, not a truck.
My guess is a van has less heat loss to the outside because the hood (though not insulated) is much shorter, and about half the engine is behind the firewall, inside the passenger compartment.
Even better would be to cover up the entire front end with a tarp - or better yet, some type of insulation like a sheet of thin flexible foam or even something like a shipping blanket. If you add magnets like these to the perimeter, it makes it a lot easier & faster to put in place and remove it. A full front cover like this will also keep snow & ice off of your windshield and headlights. If snow and ice are not a concern, you could put an insulating blanket UNDER the hood. Not much chance you'll forget to remove it before driving off as long as you have to open the hood to unplug the heater. Also, the block heater actually consumes about 950 watts. That's about $0.05/hr. (in the winter) where I live. Average electricity cost is about twice that.
In this post, I make the case that if adding an oil pan heater, it should be a 12vDC 150-watt heater because that allows it to be used as a stop-gap for occasions when AC grid power is not available. Of course it could also be used when AC grid power is available, too, simply by hooking the batteries to a 12-15 amp power supply or charger, which has another useful benefit: it keeps the batteries topped up too.
Some people worry (too much) about being able to start the engine in cold weather after putting a 6 amp load on each battery for a couple hours. Beyond doing the math on how much of the available energy that ~300 watt-hours amounts to, there's another easy answer to that concern: bigger batteries.