Community Forums

series60man · 11-09-2013, 09:24 AM

With my Detroit diesel, I preheat below 40 for better engine oil circulation at start up and less battery strain. My factory engine bay 110 plug in failed do to high amp draw and heat. I now plug it direct to outside AC with a 12 gauge 25 foot cable and it melted at the connection to RV heater cord. Replaced both plugs at that connection with commercial grade and it works fine. Mine is 1800 watts so only good on a 20 amp circuit. If the temps are 25 or below I heat the engine all night.

Maladjusted · 11-09-2013, 09:26 AM

The newer Cummins have a heater grid in the intake manifold that heats the intake air. My Duramax (2001) has the same system. I've been far up North (Canada) and started my truck at 10 below zero.

Turn the key on, wait for the "wait to start" light to go out and it fires right over.

You can see the heater grid cycling on and off with the voltage meter.. It draws quite a bit.

Cat320 · 11-10-2013, 09:27 AM

My manual says to use the preheat if 40 degrees or colder.

Mekanic · 11-10-2013, 10:36 AM

Quote:

Originally Posted by Statgeek

We live Texas and camp pretty much year round (not full time). This is our first fall with a DP. In terms of outside temps, when should I start to preheat the engine? So...how cold is cold enough to need it, and then how far in advance should I turn it on??

I'll use mine anytime its below 40*. usually a full hour is all that really needed to make a difference in starting. Don't plug in for comfort do it because it will make your engine and starter last longer.
Most smaller diesels use a 600Watt element.
A timer will pay for its self very quickly.
Years ago I used a timer (cheap household unit) on the heater in my tow truck. it worked great. I had it set to run form 9PM to 7AM If I remember correctly.

If I've done the math correctly I pay 8.4 cents per kilowat hour.
So for anything that uses 1000 watts for a hour I pay 8.4 cents.
8.4 cents X 24 hours = $2.016 1 day
$2.016 X 7 days = $14.11 week
$2.016 X 30 (month) = $60.48 But that is plugged in 24/7!!

Maladjusted · 11-11-2013, 11:43 AM

BTW... The Cummins ISB powerplants don't have a block heater.

Edit: Internet research is showing the selling dealer was mis-informed. Apparently there is a block heater installed, but perhaps not a cord. Stupid. Now I have to go look.

t55watson · 11-11-2013, 11:54 AM

Quote:

Originally Posted by Maladjusted

The newer Cummins have a heater grid in the intake manifold that heats the intake air. My Duramax (2001) has the same system. I've been far up North (Canada) and started my truck at 10 below zero.

Turn the key on, wait for the "wait to start" light to go out and it fires right over.

You can see the heater grid cycling on and off with the voltage meter.. It draws quite a bit.

My rig was built with heater grid and a in line water heater. The grid crapped out and my mechanical shop estimated over $700 to repair. I said NO and use the water heater. Is that what you folks are calling a block heater? Mine isn't in the block but in the lower radiator line.

Mekanic · 11-13-2013, 09:05 AM

Quote:

Originally Posted by Maladjusted

The newer Cummins have a heater grid in the intake manifold that heats the intake air. My Duramax (2001) has the same system. I've been far up North (Canada) and started my truck at 10 below zero.
Turn the key on, wait for the "wait to start" light to go out and it fires right over.
You can see the heater grid cycling on and off with the voltage meter.. It draws quite a bit.

It will still extend the life of the engine and starter if you could plug in the heater.

Quote:

Originally Posted by t55watson

My rig was built with heater grid and a in line water heater. The grid crapped out and my mechanical shop estimated over $700 to repair. I said NO and use the water heater. Is that what you folks are calling a block heater? Mine isn't in the block but in the lower radiator line.

Really they are coolant/water heaters. They heat the block by heating the coolant the heating element doesn't touch the block at all even on the one mounted in a freeze plug hole.

palehorse89 · 11-13-2013, 09:13 AM

If it is 40 or below I turn mine on before going to bed, my block heater keeps my ISC at 120 deg. for startup......engine sure starts a lot better even with the intake grid heater working also.

DSL417 · 11-13-2013, 09:14 AM

Not really needed by the engine until the temps drop down to 10 degrees. At least that's what Cummins told us. And make sure you turn it off or unplug it before you leave...it takes about all most alternators put out, levying little to recharge chassis batteries.

palehorse89 · 11-13-2013, 09:19 AM

Dave the block heaters in question operate on 120 VAC not off the 12 VDC batteries.

Sky_Boss · 11-13-2013, 09:21 AM

Quote:

Originally Posted by DSL417

Not really needed by the engine until the temps drop down to 10 degrees. At least that's what Cummins told us. And make sure you turn it off or unplug it before you leave...it takes about all most alternators put out, levying little to recharge chassis batteries.

HMMM....

Mine only runs on shore/genny power. I know that because...my meter spins like a top with it on. It does look like it is on a different leg than the electric water heater.

Of course, that leads to the question of why would you have to start the engine to get power to the block heater in the first place.

garbonz · 11-13-2013, 09:23 AM

Quote:

Originally Posted by vtwinwilly

I'll turn mine on below 35 a couple hours before I plan to start it.

Yes, I can see the temp rise on my dash gauge. Usually gets up to about 130 or so.

This past January while in northern Illinois I discovered that when its really cold (4 degrees F) that the engine won't even crank. You turn the key and nothing happens. Heat the block up though, and it fires right up. Apparently there's a lockout circuit that prevents the operator (me) from attempting to start the engine when it's really cold out.

X2. My VW TDI's won't start below 4 F without a oil pan heater.

My Duramax doesn't seem to care.

I donno about you big rigs, but is is a good long term idea to use a block heater below freezing for the longevity of the engine, but not absolutely necessary.

mel s · 11-13-2013, 09:43 AM

Quote:

Originally Posted by vtwinwilly

One more thing.

Be sure to turn the block heater off before attempting to start your engine. This instruction should be in your owners manual.

Here's the theory...

Even though your block is heated, the radiator still contains very cold coolant. When this cold coolant hits the very hot heater element, the element can be damaged.

I've messed up a time or two and forgotten to turn mine off. Heater still works so apparently it's somewhat forgiving.

!
I've read that the electric elements of block heaters are very fragile when energized/hot.
The manual that came with my ZeroStart frost plug block heater warns that the vibration of engine starting and/or engine running while the element is energized can/will cause premature element failure.
Mel
'96 Safari, 3126 Cat

Mekanic · 11-13-2013, 04:15 PM

Quote:

Originally Posted by DSL417

Not really needed by the engine until the temps drop down to 10 degrees. At least that's what Cummins told us. And make sure you turn it off or unplug it before you leave...it takes about all most alternators put out, levying little to recharge chassis batteries.

Sure they tell you you really don't need it. with enough cold starts they will be right there to sell you a new engine when you need one.
Ever wonder why those 18 wheeler OTR truck drivers Do NOT shut off their engines in the Rest areas/Truck stops? keep 'em warm and they last much longer.