Warm up idling

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I have noticed a lot of people running their cars in the morning for 5-10 minutes to warm it up. It is nice to have the car nice and toasty when its 5 F outside, but it seems to me that you don't do your engine any favors with excessive warm up time. I would say let it run for 1 minute tops and then don't drive it hard for the first 5 minutes of driving or until the engine gets up to temp. What do you think, wouldn't this reduce fuel dilution in cold weather somewhat?
 
What benefit exists from the quickest warm-up possible? I understand this from a catalytic converter point of view, but for engine internals, causing the most rapid possible expansion of components is best?

I let my truck warm up for 2 reasons...I hate driving a cold car, and my engine makes a raspy rattling noise at anything over 2000 rpms until the oil gets warmed up. I can only assume this comes from contraction and stiffness of valvetrain components, so forcing the engine to make these sounds can't be beneficial. The noises go away when the temp needle approaches 'normal' so I let it warm up gradually before driving it. Also, I live about 1/4 mile from the highway, which necessitates a pretty brisk acceleration from my side street onto the service road... unless I want to get hit, or sit there until lunchtime. I rather do this after the engine is warm.
 
my rule is to idle until oil is gushing from the lifters, then drive slowly 'til at least 10 minutes after the coolant comes up to op temp.

how do I know when oil is "gushing" from the lifters? I take a flashlight and have a look-see inside the filler hole. I've done this at various temps from 0F to 60F so I have a good idea of the time it takes.... ~25 sec at 60F, ~90s @ 20F, ~160s at 0F (for a "typical" 5W30). exact time of course depends on the oil.
 
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I let my truck warm up for 2 reasons...I hate driving a cold car, and my engine makes a raspy rattling noise at anything over 2000 rpms until the oil gets warmed up. I can only assume this comes from contraction and stiffness of valvetrain components, so forcing the engine to make these sounds can't be beneficial. The noises go away when the temp needle approaches 'normal' so I let it warm up gradually before driving it. Also, I live about 1/4 mile from the highway, which necessitates a pretty brisk acceleration from my side street onto the service road... unless I want to get hit, or sit there until lunchtime. I rather do this after the engine is warm.


In that situation I can see warming up the car, and my point wasn't no warmup, but not excessive warmup. Do you let the car idle in your driveway for 15 minutes like my neighbors? It just seems excessive (say more than 3-5 minutes) warmup may do more harm than good.
 
Nah...15 minutes would only be necessary where I used to live, Wyoming - where 15 minutes might get the coolant temp up to freezing. :-) It only takes my truck about 7-8 minutes to get the temp up and valvetrain sounding normal. After that, I can only hope the transmission is warming up on the short drive to the highway.
 
if warming up your car is hard on your engine,it is far harder on the engine when most people start their cars on a frigid day and take off...most people drive their vehicles hard!!! and can eventually ruin an engine far faster then to let it sit and warm up....i always learned, especially when we have been having below zero temps., to let the car sit for 10 min or so to warm up and then take it easy until the car is at operating temp.
 
I warm my car up on really cold morning for 5-10 mins for safety - I want my heater defrosting moisture on the window when I start driving. If I start driving, and my breath, steam from my coffee, or washer fluid on the winsheild freezes on me, I can't see anything, and am not safe. I'm not going to risk an accident for 5 mins worth of gas idling!
 
If someone needs to idle their car 15 minutes ..they would surely be wise to invest in a block warmer. Way cheaper.
 
I previously lived a block an half to the freeway ramp.
after Bitoging I decided to drive easy down to the next ramp and get on after the termostat opens.
 
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I have noticed a lot of people running their cars in the morning for 5-10 minutes to warm it up. It is nice to have the car nice and toasty when its 5 F outside, but it seems to me that you don't do your engine any favors with excessive warm up time. I would say let it run for 1 minute tops and then don't drive it hard for the first 5 minutes of driving or until the engine gets up to temp. What do you think, wouldn't this reduce fuel dilution in cold weather somewhat?




You have to watch generalizing that one time frame will be good for all engines and locations.

When it is -15f here in a morning, the truck needs much more than one minute to get the oil flowing around the engine.

Anyone doing a 60 second idle and pulling away isn't doing themselves or their engines a favor. With teh rings not wormed up, compression will be down a bit and therefore you will more than likely be introducing more furl into the oil than letting it idle for 5 mintes total.

I agree 10 mintes is a waste, but you have to watch swinging to the other extreme as well.

I would say 3 minutes would be a good overall comprimise for most conditions.
 
I have always use the Full Synthetic Engine Oil in Engine and Full Synthetic Fluid in Automatic Gear-box in my wife's 1994 Ford Granada (U.K.) because she takes the kids to School every morning.
When there is a overnight frost, the car idle to dis-mists the ice from the front & rear screen which takes about 1 to 2 minutes before she drive off, any other times she starts and drive off slowly to 30MPH on main road and 50MPH on motorway and the Engine Temp is warmed up quickly to ensure to save fuel wasteage.
In the past we have a issue with loud tappets noise when using Mineral Engine Oil on the first start up and after I changed for Fully Syntheic 5W/40 it stops and have noticed how quickly the Auto-Box warms up too, but never get hot to overheat, even on hot days.
Now she have asked me to change the old Power Steering Fluid out and to use the Full Synthetic Fluid which is the same type as the Auto-Box to get rid of that 'Morning Sickness' - I don't mean the wife! We have got enough kids LOL!
 
Block heaters for the win. I use one and idle 2-3 min on a cold morning. I used to be an excessive idler before I had it. Now a couple minutes idle and the car is warm. Much easier on the motor than a long idle or a slow takeoff. Pretty easy to install on most cars, the most effort is draining the coolant and bleeding the air out when refilled. Which is something we should all be doing periodically anyways
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I have noticed a lot of people running their cars in the morning for 5-10 minutes to warm it up. It is nice to have the car nice and toasty when its 5 F outside, but it seems to me that you don't do your engine any favors with excessive warm up time. I would say let it run for 1 minute tops and then don't drive it hard for the first 5 minutes of driving or until the engine gets up to temp. What do you think, wouldn't this reduce fuel dilution in cold weather somewhat?



Many cars will suffer severe gas dilution in the oil if idled for that long of a time. It's much better for an engine to be driven as soon as oil pressure is up than to sit for extended periods at idle.
My best friend is the kind of person that turns the key and takes off before the oil light is ever even off in the mornings. It doesn't seem like the best thing to do on the cold mornings(15-20F)but his truck just passed 300K with no repairs so it's hard to dispute his tactics. I guess it proves that what we sometimes think is good for an engine really isn't and what we think would damage an engine is actually good for one
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Does that make any sense at all?
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I have worked in the fire service for over 30 years. Gasoline motors take a beating. Start up and take off with little or no warm up. That is one of the many reasons, we use diesels in about anything, that is used in emergency apparatus. Idle times on Ambulances are sometimes hours at a time. With regular maintenance, the diesels last for a long time. I know this can be construed as a comparison, apples to oranges.

Truthfully, I have always like to warm up cold metal a little before applying hard force to it. Put a good strong winter oil in the motor and arrange the oci to be in the spring or warmer weather afterwards. I believe that is the key. My oci's are due in April.

Nobody drives perfect all of the time. Look at all of the cars that have high mileage success. What is the average time for owners, that allow for a engine warm up?
 
My Corvette is parked outside overnight, and there have been many times in the last couple of years where it was below 0F and I started the engine and immediately pulled away. I make sure to drive extremely gentle while the engine is warming up though, for instance I don't rev the engine beyond 1500rpm until the oil temperature reaches at least 80-100F. My oil analysis results have not shown any excessive engine wear at all with this practice, in fact my engine wear numbers in the winter are pretty much the same as they are in the summer! Although I will admit that I have underground parking at work, so even in the cold winter there is only one cold start per day instead of two. (my oil temp when I start up the engine at 5pm is usually about 60-70F)
 
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My Corvette is parked outside overnight, and there have been many times in the last couple of years where it was below 0F and I started the engine and immediately pulled away. I make sure to drive extremely gentle while the engine is warming up though, for instance I don't rev the engine beyond 1500rpm until the oil temperature reaches at least 80-100F. My oil analysis results have not shown any excessive engine wear at all with this practice, in fact my engine wear numbers in the winter are pretty much the same as they are in the summer! Although I will admit that I have underground parking at work, so even in the cold winter there is only one cold start per day instead of two. (my oil temp when I start up the engine at 5pm is usually about 60-70F)




I agree, this is the best advice... though short of a corvette, its tough to get going anywhere keeping it below 1500... I keep it there as far as I can, but then do 2000 and 2500 rpm after a while... I take my time inbetween though.

Works well for me, here in the 'tropics' (compared to your neck of the woods
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JMH
 
Below 1500 rpm, yeah right, thats only a dream for a corolla, where you don't even have any torque until you hit 2000.
 
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