Idle/Warmup time?

[JGrefenstette]

just out of curisosity. how long to yall let your truck warm up for. in all different temps?



my rule of thumb is usually, on the first start of the day. to let it idle untill the temp needle is just on the right side of that very first bold-white dash. in the summer 80* that may take 5-10 minutes. winter 20* it may take 10+ minutes. am i waiting to long? the white haze smoke seems to clear after say 3-5 minutes. and the first few times i start from a stop and let out the clutch it puffs white.

 

[KOG]

Crank it, put it in gear and drive it away. Idling when cold washes oil from the cylinder walls and causes considerable wear.

 

[DVolk]

Idle/ Warmingup time ?

I disagree with the notion that idleing wears out your engine

by washing away oil to the pistons .



The oil will be on the pistons reguardless of engine RPMs Deisels are a low

RPM engine . There is sevral engines that never get shut down in fact the oil is changed while its running or they are only shut down for a very short period of time .



How ever i do not think you need to idle your engine longer than 2 minutes by that time your oil pressure has came up plus the oil has reached operateing tempatures

 

[JLEONARD]

I crank, wait for the needle on the oil pressure gage to climb halfway, then I start rolling.

Usually buckling my seat belt is enough time for the above.

I don't drive it hard until it warms up a bit.



The exception might be if I have to wipe snow off or scrape windows... . then I "might" let it idle while I do those dirty deeds.



My theory is that I simply don't feel like hanging around shivering while the truck warms up... . nothing to do with washing the walls or the windows.

 

[JGrefenstette]

well i guess what yall are saying is ive been idleing my truck WAY too much? huh. good to know. ill try some of your methods.

 

[Forrest Nearing]

zero...



I fire it up and start driving. easy on the throttle untill the engine temp hits 160 or so... 10psi boost or less. easy/moderate throttle after that untill the thermostat opens for the first time. I never go WOT till the engine reaches operating temp.



the sooner you can get heat in the engine, the longer the engine will last. it's designed to run hot... it'll take forever to get there just sitting there idling in the cold.



a gas engine will heat up pretty quickly due to the higher exhaust gas temps, but with our cold idling EGT's and a huge cooling system, you're doing more harm than good letting it idle. Heck, I shut mine down even in the summer. A lot of guys I work with will let their trucks idle all day so that they'll have cold AC when they hop back in the truck (we work in the field)



If I let mine idle, even in the summer, when I drive away it'll gray smoke out the exhaust till it burns off all that diesel buildup

 

[JGrefenstette]

i see. what about when its cold enough to make the heater cycle on and off? Should i at least wait untill its done cycling to drive?



strangly enough, my truck idles at about 350* when i start it on a cold morning. after it warms up it idles at about 280*. keep in mind that when its cold it will be at about 700rpms and when its warm its at about 880-900rpms.

 

[Forrest Nearing]

I've got my heaters disconnected, but when they were connected, I would still just get up and drive. just take it easy on it.



when it's cold, mine idles below 200*

 

[JGrefenstette]

so i dont understand why mine would idle at 350* when cold? could my IP be sending more fuel than yours causing higher egts? or does it have to do with the KSB advancing pump timing untill warm?

 

[JDancoe]

With either my '06 or my '92, I give it about 1-2 minutes if the temps are above freezing. If it's below freezing I plug my block heater into a timer to come on about 4 hrs. before anticipated start up, then 1-2 minutes.

 

[Madurski]

I disagree with the notion that idleing wears out your engine

by washing away oil to the pistons .



The oil will be on the pistons reguardless of engine RPMs Deisels are a low

RPM engine . There is sevral engines that never get shut down in fact the oil is changed while its running or they are only shut down for a very short period of time .



How ever i do not think you need to idle your engine longer than 2 minutes by that time your oil pressure has came up plus the oil has reached operateing tempatures

I believe the issue is idling when cold (really cold). The heavier hydrocarbons precipitate out at lower temps and this is what washes the cylinders and accelerates the wear. However, I've never reasoned out why running under a load when it is cold reduces this effect.



Personally, as soon as the oil pressure is sufficient I start rolling, cold or hot.

 

[Forrest Nearing]

I believe the issue is idling when cold (really cold). The heavier hydrocarbons precipitate out at lower temps and this is what washes the cylinders and accelerates the wear. However, I've never reasoned out why running under a load when it is cold reduces this effect.

running under load increases temps... so whereas it might take an hour of idling to reach 160*, it now takes 6 minutes. a lot less time washing the cylinder walls

 

[JGrefenstette]

why is it that big rigs never shut their trucks down. im not talking about at truck stops where they use the motor for a/c, tv, fridge, and all that. i mean if they go to a diner or anywhere they will let their trucks run the entire time. loading docks, theyll sit there for hours chuggin away.

 

[cojhl2]

why is it that big rigs never shut their trucks down. im not talking about at truck stops where they use the motor for a/c, tv, fridge, and all that. i mean if they go to a diner or anywhere they will let their trucks run the entire time. loading docks, theyll sit there for hours chuggin away.

There are multiple reasons:

1) After running hard the engine should not be shut down right away. So sometimes it is just more convienient to leave it run during short stops rather than sit and wait for cool down. (Trubo is the least of worries, it's the engine internals)



2)Regardless what some say, you should never put an engine to work cold. The engine should be normalized so when power is applied the engine does not go thru a temp change shock.



Now regarding 1) above. Some big trucks are equipped with timer shutdowns. This allows the driver to leave the truck immediately while it cools and subsequently shuts down.



regarding 2) above: A lot of trucks today have the logic to remain shutdown until the oil temp drops to 100degF, at which time it automatically starts and runs until the oil is back to temp.

 

[JGrefenstette]

yea that makes perfect sense. and i agree about not putting an engine to work cold.

 

[DodgeWarlock]

I crank it put it in neutral to circulate trans fluid and wait for full oil pressure which only takes long enough to buckle up, put on my shades and check the gauges. However, I don't do any hauling or towing until it has warmed up a little if at all possible. I do most of my idling after driving to cool down, especially if towing a load or pushing it.

 

[tugboatphil]

Some days I just start my truck and let it idle in the driveway. It's mainly to deplete the rapidly decreasing ozone layer. I also like wasting our precious natural resources. We have a lot of hippies around here and I just like giving them reasons to hate me (more).

 

[BWJensen]

^:-laf I love it, classic!!:-laf



MADDOG

 

[MMiller]

My first gen has never had problems getting to operating temp while idling even in sub zero temps. I have two opinions on this topic, and it relates to load and cold engines.



When my truck is hooked to my trailer, it will idle for 15 minutes or so before I leave the driveway. I cannot pull my trailer down the road without building boost. I've blown my headgasket before on a cold morning, taking off too soon. I also blew alot of headgaskets in my VW Rabbit Diesel, by taking off after school on a cold day, and checking the governor spring at the end of the driveway. :-laf



When my truck is empty, unladen, and I can ease down the road, I make sure the boost gauge does not hit 10psi until I have almost hit operating temp.



Now I don't condone idling long or often, but I will not put a tractor, a semi, a dozer, or even a gas engine to work until everything is warmed up. The trucking industry is in for many changes, when it comes to idling. I do know though if its below freezing, my service truck will not shut off until I'm home, if I have to work outside. I'm not going to be stranded, and I'm going to have a place to climb in and get warm if I need to.



Michael

 

[JGrefenstette]

Some days I just start my truck and let it idle in the driveway. It's mainly to deplete the rapidly decreasing ozone layer. I also like wasting our precious natural resources. We have a lot of hippies around here and I just like giving them reasons to hate me (more).

i couldnt agree with you more everytime i pass a hybrid car i try to pour as much coal on them as possible just to let them know im neutralizing about a dozen of their stupid little save the planet vehicles/golfcarts :-laf

just doing my part to let them know that the great work their doing to conserve the earth is all a waste thanks to our right foots