I've heard that it is cheaper to let the motor idle rather than turn it off and start it back up.

how long should I let the truck idle before it becomes cheaper to turn it off and start it back up.

10 minutes
30 minutes
an hour

an ideas?

 

If you have a new truck I would not let it idle for more than 5 minutes. If your truck is broken in, 10 minutes seems fine but anything else seems excessive. All of the current diesel trucks will idle faster after a while to help prevent wet stacking. Wet stacking occurs when combustion temperature is too low and fuel gets into your oil. The problem with the factory "fast idle" is that it often is not high enough to prevent wet stacking, especially in cold weather. The big rigs don't have this problem because they have features on their engine to prevent this that you don't.

If you feel you must idle for extended periods of time do yourself a favor and get an Auxillary Idle Controller. You can set the idle high enough to prevent wet stacking. If you have a pyrometer, you can take the guess work out of it.

 

I let my 550 idle for hours on end to operate the hydraulics for my crane and air compressor oh and can't forget the A/C. Gotta have cold blow. I send my oil sample to CAT every 3,000 miles. Have not had any reports of any diesel in oil. Truck has 24,800 miles on it now and 19,800 hours. It gets started once a day so it saves wear on glow plugs and the starter. Steady running basically eliminates heat and cool cycles. So you know what I say...If you feel like a Pete driver that day...let 'er run !

 

04F250CC60, I would imagine that you are putting some load on your engine if you are running accessories off of it and that will help to keep the engine temps up. If you just idle, the EGT will drop off too much even in moderate weather.

 

The idle speed does increase slightly under a load while operating the PTO. If I idle at a job for the day I have noticed a fair amount of smoke for a half mile or so as I drive away. That is why I always inquire on fuel parts per million in my oil sample. I change the oil every 3,000 because if the extended idling.

 

As far as how long to idle versus start up cost, I would think that idling more than a minute would cost more than the amount of fuel burned to start the truck back up.

In Europe, one of the auto manufacturers uses a diesel in their high MPG micro cars. If you come to a stop at a light the motor turns off. When you press the pedel when the light turns green, the motor starts and the torque converter kicks back in and away you go. Obviously they feel that the wear and tear of starting the diesel, plus any extra fuel burned is far outwieghed by the savings in fuel and emissions during the duration of the stop light.

Daryl

 

your truck has a hour meter on it??

 

In the winter time here on the North Slope of Alaska, a lot of our trucks run 24 hours a day. They hardly get shut off, MAYBE just to check the oil level, but then start right back up. Almost all the trucks are equipped with Auxillary Idle Control (AIC) modules so they can idle at a higher RPM. This allows the engine temps to stay higher and helps prevent the catalytic converter from plugging up. It seems like when the EGT's are low, the catalytic converter has a tendancy to plug up. The truck I used (2003 F-350 with 6.0) plugged the catalytic converter up and it took about 100 miles of driving at higher RPM's to blow/melt everything out and get things back to normal. One time it even had to go to the shop to have the converter cleaned out, or maybe even replace (I didn't get to see the work order).

Oil consumption also seems to increase when idling at low RPMs for these extended periods. Since you have to manually engauge the AIC, some people forget. I left for 2 weeks and when I came back the truck was 5 quarts low!!! This was with a 7.3L PSD engine; I haven't noticed this excessive comsumption with our new 6.0 PSD engines. Could have been that when the truck was new it idled extended periods at low RPMS and the rings didn't seat, but I don't know for sure. I only drive the truck 50% of the time because of a 2 weeks on, 2 weeks off work schedule. To manually engauge the AIC, you have to apply the parking brake and then push a button on the AIC. I have seen some vehicles that automatically go to high idle when the parking brake is applied, I don't know if this is programmable into the AIC or a modification.

Personally I don't like frequent stopping and starting of a diesel engine and will let it idle (at higher RPMs) for up to about 30 minutes periods. If I don't plan on using it for a longer period of time, I would have shut if off as soon as the turbo cooled down. I don't plan on letting my new truck idle for longer than 5-10 minutes until the engine is broke-in. I get my auto start installed in 2 weeks. This will allow me to push a button on the remote, remove the key from the ignition, leave the vehicle idling, and feel a little less worried about vehicle theft. A nice feature for those quick stops where you run in and will be right back out.

 

24,800 / 19,800 hours = 1.25 miles per hour! I thought my mother-in-law drove slow. Just kidding. I know these trucks can really rack up some hours idling. I thought about putting an hour meter on my new truck but have had too much fun driving it that I forgot. I might install one when I change my oil. I know my Bobcat Kubota engine specs an oil change at 250 hours. Does anyone know how many hours are recommended for an oil change on the 6.0 PSD?

 

good to know, I couldn't imagine how cold it is up there. Some day I'd like to visit, but definetly not in the winter. BTW what do you do up there?

when I have to run in to get some water or something, I just lock the doors then use the key pad thinge above the door handle to open them again. THe alarm I want to install on the truck is completely overkill ($1500) so the manual lock method will work until I fall into some extra cash.

what is the recomended break in period? the sales guy said 500 miles before you tow, but that was all he said about break in, and he was pretty informed about the diesels (bought it from a dealership in a farm community, you have to know diesels to survive at that dealership)

 

I'm a Measurement While Drilling engineer. I work in conjunction with a drilling rig for oil exploration and development. We provide real-time directional and lithology data to accurately drill a well in the hydrocarbon bearing formations.

The manual recommends 500 miles before towing, but the concensus on this forum seems to be 1,000 miles before towing. In another post, there was a good link about breaking in a diesel engine. Just do a search for it an you should come up with plenty of information.

I found the thread! Here's the link: https://www.ford-trucks.com/forums/s...ghlight=break+

 

Here are a few questions for you guys to answer. I thought these might be some good questions seem so we are talking about idling.

What about when you first start up your truck in the winter, how long to idle before driving away? Is 5 min. enough? When the temp is decent outside through the spring and fall season is it okay to just get in and go? Will it bother a diesel to turn it off and restart it for say when you are in construction as you would with a gas engine? I normally leave my diesel idling for a few minutes if I just run into the store quickly as I figure that letting it idle for no purpose just puts wear on the motor and burns fuel. Please help with the questions. Thanks guys!

 

More opinions. I let my truck idle a few minutes (3-5) less when warm and more when cold. I take it real easy on the engine until the temp gauge is up in the "normal" range.

 

For what it's worth: when we idle our trucks all day at higher RPMs (1250-1300) we burn about 3/8 - 1/2 a tank. This is a "38" gallon tank so about 12.35-19 gallons. That calculates to about 0.51 - 0.79 gallons per hour. Like I said before, we don't meter the fuel when refilling so just going by the gauge level.

 

Yes I installed an aftermarket Hobbs hour meter as soon as I recieved the truck. The hour meter is powered when the key switch is in the "Run" position. Since I spend 10-12 hours running a day and drive maybe 30 miles I opted to add the hour meter. If I were to reach 250 hours before the 3,000 mile mark the oil would be changed then. There are days that I put 400+ miles on the rig so I hit 3,000 pretty quickly. I've noticed that the newer Chevy HD's with a gasser are equipped with a hour meter. Humm....