Engine warm-up in the morning. Is it necessary?

Lots of great advice on this topic.

I'm happy to read that I have been doing the correct procedure according to the majority of posts.

I don't rush moving my Tacoma unless the garage or house is on fire. Slow and steady is my motto.

I might not beat the young guys in a sprint, but I'll do my best to go the distance!

 

fast5Speed

Actually engine technology (tolerances and materials) has come a long way since the "old days". Long warmups by idling in the driveway are no longer necessary and I stand by my statements. When it's very cold I still drive off after a minute or so, but keep my RPM's on the low side and don't rap out the engine. Benefit of doing this is that the engine warms up faster than just idling the vehicle for 10 minutes when cold.

BTW, if you operate in very cold temperatures, I recommend using synthetic oil. Startups are much easier on the engine with synthetics in this case.

Re "the high temp of the day would often be -~50F or colder in the winters" in Canada...well that's a whole different ball of wax than most of us experience in the lower 48. Best not to drive at those temps if you don't have to. When it gets extremely cold, even tire rubber becomes very hard and subject to damage. I used to live in Michigan.

Re "people never turned their diesels off. Just let them idle all night long. Because those fuckers wouldn't start up again in the morning"

As far as diesels are concerned, have you ever owned one? I've driven them for decades...engine block heaters have been available for many years. Just plug it in anywhere from 45 minutes to 3 hours (or use a timer) depending on the winter temperature, and they fire right up...never had a problem. With the added benefit of the engine warming up quickly and thus providing warm air for the vehicle's occupants.

But even without the block heaters, diesels don't have much trouble starting in cold temperatures. Never had trouble starting my diesels in the winter, even without the block heater. But I did and do use (Mobil) Delvac 1 5W40 synthetic oil.

I try not to abuse my vehicles and operate them for maximum fuel efficiency...I run most of em to 300k miles or more.

peace

 

Then I would suggest that you stop posting incorrect information based on uninformed assumptions.

FYI, materials used in engines have changed. Aluminum conducts heat much better than steel, which evens out hot spots and warms the entire engine more quickly.
The uneven heating in iron heads was one of the reasons that older engines needed a more extended warm-up. Put enough load on a cold steel engine and you can easily blow a head gasket, and possibly crack the head from the expansion rate.
Pistons are now incorporating ceramics into the steel alloy and are much more size-stable under various temperatures.

Basic physics has not changed, but which formulae to use has.

Even on a 50 year old engine, the clearances do not open up to the overly dramatic degree that you indicated. Ring gap is extremely small once the piston is in the cylinder. Yes, the difference between a cold ring and a hot ring DOES make a difference in blow-by, which is why engines that are routinely run on short trips need more frequent oil changes.
You will get a little piston slap, but the new pistons and sleeves are designed to tolerate this.


Nobody is saying to start a cold engine and run the piss out of it while cold. The engine absolutely WILL warm up much faster with a conservative load on it. As Maineah indicated... many engines with over 300k on them, all started and driven cold.

Start it, let it idle while you clear any ice or snow and wipe the glass down, and drive like grandpa for a couple of miles.

 

I prefer to wait to let my truck warm up when its cold for 5-10 minutes but I don't always do it. I do try to keep the rpm's down and drive easy until the coolant needle is at normal operation temp when its not warmed up. Also on 1st gen auto Tacos the transmission will shift funny because it is in the warm up stage until normal temp.

 

I run mine for 10-15 minutes every morning unless it's above freezing. It was -15 the other day and I ran it for 25 minutes and it was still too cold to comfortably drive.

I obviously live in harsher conditions than most, but warming up the vehicle won't damage anything so why not take the time and do it? Unless you're worried about burning a few bucks worth of gas of course.

And to who was saying diesel start fine in the cold, you should see the trucks on the north slope in the winter. Every single one of them runs all day and night to keep warm so they will run when needed. I'm sure they would disagree with your statement of them having no problems starting in the cold.

 

everyone who preheats their oven before throwing a turkey in is clearly a moron, because i have ran an experiment and found that the turkey actually gets cooked 5 minutes quicker if i only wait 30 seconds after starting the oven to throw it in

sure, the turkey freezes it's giblets off for the first couple of minutes in the oven; but, !#$% it... it's just a turkey, right?!

why don't you put some gloves on if your so cold, you #!$%in' turkey?!
!#$% YOU!

 

You're causing more wear by idling for 25 minutes and then driving off than by just driving, and the vehicle will warm up much faster when driven. In the big picture, it's really not a big deal either way.

 

x2 to what JLee50 posted.

 

At -36C this morning (-33F to most of you), starting it up and driving away just isn't an option. The diffs and clutch feel like they are full of glue. Even after being plugged in, I wait at least 3 songs on the radio before driving away.

Is it spring yet?

 

YUP.


And we're now way past carburated diesels and their misery



I like how a lot of people on this thread are trying to compare unlike things. The phrase "these modern engines don't need no stinkin' warm up time". Implying modern as in 2014.
You might not be aware, but the newest truck on this 1st. Gen forum is a 2004, and a lot of them are as old as 1995. I wouldn't exactly call those the most modern. All of these trucks still use iron blocks. These ain't 2014 Corvettes with all aluminum blocks and heads. Sure, these vehicles have more in common with a 2014 car than a 1950s car, but you can't just apply principles of 2014 technology to technology from 1995.

 

And where do you all stand based on the fact that pistons have differing amounts of material where the wrist pins slide through and mic oblong when cold? Matters? Matters not?

 

I can't help but notice that people that live in warm climates seem to fall in the short warm up camp whereas people that live where it gets cold fall into the long warm up camp.


This makes sense to me. I've lived in SoCal and AZ. When I lived in both of those places, a 30 second warm up followed by some easy driving worked great for me. Now that I live where actually gets cold, though, I've changed my opinion. Out here, I've got to let my truck warm up for 5 minutes before hitting the road on cold days. Even after that warm up, my rig is colder than it ever got on Cali or AZ.


The bottom line is this: You can feel when your truck is warm enough to drive. Pay attention and let your rig tell you when you can drive, and how hard to drive as everything heats up.

 

to fast5speed

Diesels never had carburetors....

Regarding the posts on living in cold climates, I've lived in the great white north including Ontario, Michigan and Colorado.

My brother lives in the Denver area and starts up his 2000 Ford 7.3 diesel every day. And often he's not in an area where he can plug in the block heater

If it makes people happy to warm up their vehicles, that is great...but not necessarily based on technical knowledge.

My neighbor likes to warm up his truck for 20 minutes in the morning in the winter. But he doesn't use gloves, etc...I think he likes the cab to be warm when he drives off.

As I previously posted, when you get down to extremely cold conditions, its a whole different ball game.

peace and do whatever works for you.

 

^This. 10 degrees isn't cold in my book, but -20 is. You need to let your vehicle give you the signs that it is warm enough to drive. In my truck's case, it needs about 5 minutes to be warm enough in negative temps. After that, it need another 5 minutes of light driving to get happy.

 

Living in SoCal all my life, I usually start my vehicle, put the faceplate on the radio, find my music, buckle up, put things where they need to be and go, driving it casually until it warms up fully. Lowest it gets in my part of SD is like 32*

On the note of "modern" engines: tolerances, materials, technology, efficiency has all changed since the Dino motors of yester year. My truck has 237k on it and it's not unusual for me to go 15k between oil changes with it still looking good, where my old 65 mustang with presumably half the mileage would look black as paint after a couple thousand.

I rebuilt a stock motor and a performance motor for my old eclipse, and I can tell you it's a night and day difference in operation. Cast compared to billet and forged, standard vs tight tolerances. I let the built motor warm up longer, as I wanted to take care of it, but also you could feel the difference a lot more in something that's built more precise.

Stock vehicles are built to a spec that is acceptable for the public to use and abuse without much thinking or strict procedures to follow and continue to function for typically 100k+ miles

 

I leave a temperature compensated smart charger (like a Battery Tender Plus, etc.) on a quick disconnect attached to my wet batteries when the temps drop below 0 degrees F and use synthetic 0-20W oil. I have never l had a problem with a battery freezing or starting my engine because it is always fully charged, especially when I make short trips or the vehicle has been parked for a couple of weeks.

 

Same, maybe a minute... and then drive a little easy until the gauge starts climbing, usually another minute or two. But I'm in Phoenix too, so this is usually only on winter mornings.

 

I wait until it idles down to get the oil flowing through the engine.

 

If it's cold, warm it up.

 

10-15 min. so I can warm up the windshield and get the snow and ice off. Im lazy hate to scrap ice.