Cold weather idling for heat

[themechanicalford]

What they do here is to use a switch to activate the fast idle solenoid which will also activate the timing advance. I can't back feed to anything since the factory "automatic" switch is in the open position at this point so electricity can't flow through it.

Why exactly do they do this?

 

[themechanicalford]

They definitely do cool off. I think the problem is that the egts get really low, and the engine just isn't making much heat, and isn't retaining much of that. If we had some way to mostly obstruct the exhaust when idling, to raise egts, that might help the engine stay warm and keep it and us comfortable. Maybe jam a potato into the tail pipe when you have to idle for a while?

Didn't the older powerstrokes have a valve in the exhaust which would close when you were idling in the cold?

I suppose I could run a hose from the tailpipe back in to the cab for heat

 

[themechanicalford]

The OP was asking about long times idling after the engine's already hot. This is to keep heat inside the cab when it's cold outside.

Exactly. I want to know if it is better to let the truck idle on it's own or should I try to bump the rpms up. The heat of fine and warm at idle, I would only be doing this to improve the longevity of the engine.

 

[themechanicalford]

@themechanicalford i use a fast idle stick, i stick it between the pedal and the seat, it works and a high idle is better for the engine. i let my truck warm up until the cold start advance/high idle turns off. then i just turn on the defrost on high and in 5-10 mins of driving i have good heat in my truck. no grille cover, no block heater, no fancy stuff. if you need to idle it for an hour for cab heat then you have some major problems with your truck

I love a low tech solution like an idle stick. I use a tire thumper to check brake lights and if I had enough clicks in the seat it would actually be a pretty accurately adjustable idle stick.

For the brakes I put the stick against the brake pedal and then slide the seat forward enough to hold pressure. Could do something similar with the idle stick.

Also, I'm not doing this to raise the temperate of cab heat. The cab is warm enough. I am doing this for times when I need to get back in to get warm or am sitting in the cab for an extended period of time. Sometimes the wife and I will go get a coffee and sit in the truck for an hour or more people watching and bullshitting. We live way up in the mountains so there's plenty of other times that the truck is idling for one reason or the other.

 

[no mufflers]

it was kinda mentioned, but what i did on my truck and plenty of others have done is you can use the high idle solenoid thats already on the engine and run switched 12v power to it to get the RPMs around 1k or so. then you would want to put a diode inline so the power doesnt back feed to the timing advance.

 

[themechanicalford]

it was kinda mentioned, but what i did on my truck and plenty of others have done is you can use the high idle solenoid thats already on the engine and run switched 12v power to it to get the RPMs around 1k or so. then you would want to put a diode inline so the power doesnt back feed to the timing advance.

Okay, so once the engine is up to temp and you want to idle for cab heat you would flip the switch and it would bump the idle to ~1,000rpm and just leave it like that until you are ready to drive away again?

Would it be better to run a separate throttle cable in some way and use that and then I could even get it above 1k RPM? Not sure if maybe a little higher would be better?

I also like the idea of the throttle stick but that will be in my way if I'm sitting in the truck.

 

[nelstomlinson]

Also, I'm not doing this to raise the temperate of cab heat. The cab is warm enough. I am doing this for times when I need to get back in to get warm or am sitting in the cab for an extended period of time.

Wow, you must live someplace warm. In the winter my trucks just get colder and colder as they idle. A winter front helps, but not much. That's why I'm thinking about some way to block the exhaust when I'm idling.

 

[no mufflers]

Okay, so once the engine is up to temp and you want to idle for cab heat you would flip the switch and it would bump the idle to ~1,000rpm and just leave it like that until you are ready to drive away again?

Would it be better to run a separate throttle cable in some way and use that and then I could even get it above 1k RPM? Not sure if maybe a little higher would be better?

I also like the idea of the throttle stick but that will be in my way if I'm sitting in the truck.

Yeah pretty much. Its just the easy way in my opinion. The end is adjustable so you might be able to a few more out it.

 

[themechanicalford]

Nope, we live on top of a mountain and it probably hasn't been above 20 degrees since Halloween, ha.

Im going to get a grill cover on there soon because it could be a little warmer but it seems to be okay once it's warmed and I idle it for heat. I'm not in a tee shirt in there but I'm not miserable though.

 

[nelstomlinson]

Okay, so once the engine is up to temp and you want to idle for cab heat you would flip the switch and it would bump the idle to ~1,000rpm and just leave it like that until you are ready to drive away again?

Almost. Flip the switch to energize the solenoid, then goose the gas pedal to get RPMs up above 1,000 and the solenoid will hold it around 1,000. Turn the switch off to de-energize it and let the idle RPMs drop back to normal.

If you start the truck cold without touching the gas pedal the high idle solenoid will be energized, but because it doesn't move the throttle you don't get the high idle. Then you goose the gas and the idle stays high until the engine warms up a bit ... if it does. Usually in winter I have to drive to get it that warm.

 

[nelstomlinson]

Yes, that's

Nope, we live on top of a mountain and it probably hasn't been above 20 degrees since Halloween, ha.

Yes, that's pretty warm.

 

[franklin2]

Why exactly do they do this?

Emissions mostly. That is also why their automatic glowplug controller cycles on and off after the engine has started. To reduce the smoke out of the tailpipe.

 

[IDIBRONCO]

That is also why their automatic glowplug controller cycles on and off after the engine has started. To reduce the smoke out of the tailpipe.

That's true. My glow plugs are on manual control. I'll still do a manual afterglow when it's below 25* and I'll still get smoke out of the tailpipe for 2-3 minutes.

 

[rhkcommander]

That's true. My glow plugs are on manual control. I'll still do a manual afterglow when it's below 25* and I'll still get smoke out of the tailpipe for 2-3 minutes.

I'd like to see a test on how much they really do help. I imagine they do to an extent but I'm not sure how much...

Glow plugs get hotter than hell, at least 1500ºF but imagining how much air and cold fuel is being exchanged every second of a 6.9/7.3 idling to counteract that heat. It would be neat to see someone test a glowplug by blasting it with compressed air and seeing how hot it gets.

It might help on an exhaust analyzer, but from our viewpoint I'm not sure really in real world testing. It only takes a couple seconds of cranking to lose most of the glow plug heat when trying to start I feel like.

Compression is already generating a ton of heat, and more heat comes during combustion. I saw some claims that the powerstroke combustion temps are around 2336ºF. So yeah more heat from plugs should help but it's not going to make a world of difference probably. It takes a couple minutes to get the block warm regardless.

A possible test would be to see how long until the thermostat opens when glowed once, versus another cold start afterglowed a few times. If warmup time is significantly reduced it's helping a lot, otherwise its not

 

[gnathv]

Your glow plugs are only meant to heat the cylinder for better combustion until cylinder warms up, they are not meant to warm the coolant.