Cat Engine Pre heat

[The Sunde's]

Any one know how long you are suppose to leave the engine pre heat turned on with a cat c7 in cold weather? The manual tells you how to turn it on but no mention of how long before you try to start the engine. Im sure it may depend on how cold ect. but there must be a rule of thumb or something..
Thanks,

[The Sunde's]

Any one know how long you are suppose to leave the engine pre heat turned on with a cat c7 in cold weather? The manual tells you how to turn it on but no mention of how long before you try to start the engine. Im sure it may depend on how cold ect. but there must be a rule of thumb or something..
Thanks,

[Pusherman]

There's generally no need to use the engine block heater until the temperature is below freezing. If it's only in the 20's, a couple hours would suffice. Maybe longer if it's colder.

I don't think it's necessary to keep it on all night, unless you're in sub-zero weather. If that's the case, head south quickly!

Edit: I also corrected the term from 'pre-heat' to the 'engine block heater' per Skigramp's note below. Thanks Skigramp.

[JRP]

Dick,

I'm not a Winnie owner, but had recently looked up the same question. My 2005 C7 coach owners manual has the following chart for the engine block heater:
above 32F - do not use
15-32F - 2-3 hours
10-15F - 4hrs or overnight
below 10F - 8hrs or overnight

it has a footnote saying these are minimum times and no harm is caused by longer pre-heating, since it only warms the block and coolant fluid. it also mentions changing to cold weather diesel blend and lower viscosity oil for extended cold weather operation.

Jim

[skigramp]

Dick ...

A couple of "hints" for starting your rig in cold weather (assuming that you have access to at least a 15 amp 120V circuit.

1) Turn on the block heater ahead of time according to Jim's formula

2) Put some sort of wedge under your MOM switch for about 10 or 15 minutes ... this will give your starting batteries a little boost ...

3) Turn on the key and let the "wait to start" light go out ... turn off the switch ... turn it back on and let the "wait to start" light go out again

4) Push the MOM switch and turn the key to start ...

Your engine should start about the second time that it turns over ...

These are hints that I have collected from GNR and various bulletin boards ...

PS. I live in Wisconsin ... in November I take my rig to a farm supply fueling place where I know they have winter blend diesel ... I make sure that I put in at least half of a tank of winter blend diesel ... I have had no trouble with fuel jelling ...

PPS ... <span class="ev_code_RED">DO NOT USE STARTING FLUID</span> ... the pre-heat circuitry is likely to cause the eather to explode or cause a fire.

[Gary CA]

A quick tip, check to see if your engine heater is actually plugged in. The switch inside the coach only controls the outlet that the engine heater should be plugged in to. Check it out, my outlet is in the electricial bay.

[The Sunde's]

A big thanks to all of you for the good information. I fell comfortable about my cold weather heater for the engine now..
Isn't this form great. More info than you can dream up...

Happy New year to all,

[gunny]

I have never seen where an hour wouldn't warm an engine to the point where it had no problem starting. Leaving them on all the time is wasteful of electricity.

[wagonmaster2]

Appreciate all the excellent replys as I have wondered the same question ever since I got my first diesel 3 years ago. I guess you would use the 15-32 degrees suggestion if the temp had been in the teens during the night but was above freezing for a couple hours in the morning just before starting.
Wagonmaster2

[JonD]

Last week in MN I tried to start without the block heater. That was clearly going fail at 20 degrees F.
I started the genny and ran the block heater for 35-40 minutes while giving the batteries some charge. Hit the MOM switch to put both banks on the start. The C7 turned over and started as if in the summer.
I want to thank skigramp for his correctness of terms. I just edited my message.

[skigramp]

We are using two terms here that we should not be confusing.

Pre-Heat
There are some heaters in the fuel / air supply that comes on when you turn the switch on ... all the time the <span class="ev_code_RED"> WAIT TO START </span> light is on these heaters are "warming" the fuel / air supply to the engine to help the fuel / air mixture combust. When the WAIT TO START light goes out the sensors believe the fuel / air mixture is adequately heated. This is a 12 V heater ... it comes on every time that you turn the ignition key from OFF to the first "notch" ... it is shut off by the sensors (or you turning the switch to OFF)

Engine Block heater
There are heating elements inside of the engine that can heat the engine itself along with the coolant and the oil. This is 120 volt heater ... and you turn it on and off manually with a switch. In colder climates you see cars and pickups with a plug sticking through the grill ... these are the cords for their Engine Block heaters ... motels in the Upper Peninsula of Michigan have outlets so that people can plug their cars in overnight when the temps are below zero ...

[Pusherman]

Thanks SkiGramp for the clarification. You are correct. I have edited my post above accordingly.