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View Full Version : How long do you let your vehicle warm up for?


Prairie_dog
12-04-2009, 10:09 AM
Simple question. I barely let it run before I start driving away with it. If I had a garage I would always start and go. However I have the privelidge of parking outside so I get to scrape windows or remove snow. Generally I start it while scraping then off I go.

Another question, how cold do you go before plugging in the block heater? About -15 celcius for me for about 4 hours before use. Longer when it is colder.

As for length of time with plugging it in it is all about saving on the power bill for me. Do it wherever I can.

bluestoons
12-04-2009, 10:35 AM
I let it run until all windows are clear and won't fog up when I drive away.I see too many people wiping the moisture from thier breath off and peeking through a little hole. It's a safety thing.

bigbuckguy19
12-04-2009, 10:53 AM
Depends on how much time I have. If it's about -10 or more I usually plug it in all night long. If i'm pressed for time I don't usually worry to much about driving it after a cold start. I usually wait a few seconds after start just to get the juices flowing and then I just get the RPM's to high until it's warmed up a bit. But I usually park in the garage at home so I'm spoiled and don't have to warm up the truck before I go :)

Prairie_dog
12-04-2009, 11:22 AM
But I usually park in the garage at home so I'm spoiled and don't have to warm up the truck before I go :)

My dad had the nerve to tell me recently that parking outside was for the birds cause he had a truck outside for a few months. I wish haha.

jkeficat
12-04-2009, 11:26 AM
summer...a few minutes..winter 10-15 minutes (command start runs it 10 minutes),,,a mail-out from GM said to only warm up 30 seconds,,,u know to save gas...lol
as for plugging my 07 gmc has the switch in the plug-in so it only works if its below -17 c. i did not know this until my brother told me this, this has been on vehicles a few years now...again to save energy!!:thumbs_do

PAPA BEAR
12-04-2009, 11:33 AM
depends if i leave it out or if it is in the garrage..Plug it in as soon as the temp hits -15...I use 5-30 in the winter, should go to 0-30 cause it sits outside at work all day.

Starting a cold engine without it plugged in will shorten the engine life a lot..I even like to have block heaters on both sides of a v8 just so the temp is the same on both sides...

If U have ever pulled down a v 8 with one block heater, U will see the wear from one side to the other.

These aluminum blocks, need to be warmed up..

Prairie_dog
12-04-2009, 03:30 PM
I let it run until all windows are clear and won't fog up when I drive away.I see too many people wiping the moisture from thier breath off and peeking through a little hole. It's a safety thing.

My vehicle is bad for fogging up inside as soon as the defrost hits the window until it warms up. I figured out a fix for it by running the a/c which has a dehumidifier. Works good and I'm pretty serious about clearing all my windows before I get behind the wheel.

buck dominator
03-28-2010, 08:24 AM
the diesel gets plugged in when it is around -5 and I let it run for a half hour in really cold weather even in the summer I let the motor warm up properly before I move the truck the wifes van on the other hand is in the garage so as long as it has a chance to splash the oil in the block around a bit good enough.
The diesel you have to let warm up properly and I even let cool down when it gets warm. If you don't you'll be replacing motors all the time and at 10 000 a crack I think a little power to plug it in and a little diesel to warm the motor up is not a big deal to me. If my truck had one of those switches to not turn on the block heater till -17 it would get cut out!!!

BeerSlayer1
03-28-2010, 12:09 PM
plugging in the block heater? ........... Longer when it is colder.


When I was in university one of my electrical engineering profs explained to us that for maximum efficiency the colder it is, the SHORTER the time you need to plug your vehicle in. :confused:

When you plug your vehicle in the block heater will warm your engine up to a point where it reaches a steady state (constant temperature). Once this steady state is reached you're not gaining any further benefit to having your vehicle plugged in.

When it's colder, the steady state temperature reached will be lower but it will be reached sooner.

I can just see everyone's eyeballs rolling back in their sockets. Maybe I'll have to draw a Time vs. Temperature graph to explain it better.

redcrew71
03-28-2010, 12:48 PM
He is right....a block heater will only heat up the oil to a certain temp....thye do not have a very high temp output....this is usually....(I heard) an hour to 3hrs)....

...i had my truck on a timer for 3hrs and it works just fine....

SEAQ
03-28-2010, 06:29 PM
Just at my garage -- machanic was doing an engine then in a P/U -- not happy the owner starts it and VOOOOOM -- gas down and gone. This is not good as the pistons get hot fast yet the block is cold and cooled by antifreeze and takes longer to warm resulting in block scoring, then there is the oils and transmission they are cold not good. Yes you need a brief warm up also the first bit driving you need lower RPM to give things a little time to warm-up.

ERIC

The Provider
03-28-2010, 07:30 PM
Firing up and instantly driving a cold engine will DEFINATELY shorten engine life. I let mine run 3 to 5 minutes when it's 0 to minus 10. Colder than that it's ten minutes minimum. Fuel is much cheaper than an overhaul. I even let it run a bit in the summer before driving. My block heater doesn't work until it is below -18. Not one of Chevy's better ideas. When at home I use a timer and my truck is only plugged in for 4hrs. At work it's all night. During the day it sits in the middle of nowhere and I set my command start to run it every two hours and it runs just under 15 minutes.

redmist
03-28-2010, 07:43 PM
About 10 seconds .

grandson_of_a_sealer
03-28-2010, 09:59 PM
Cobalt with manual transmission:
+50 C ... +10 C = 30 seconds
+9 C ... -5 C = 1 minute
-5 C ... -15 C = 5-7 minutes
-15 C ... -25 C = 10-12 minutes
-25 C ... -60 C = >15 minutes

My car is parked outside the house.

Spaceman
03-29-2010, 01:21 PM
Having a gas vehicle plugged in for more than 3 hours before you start it is a waste of electricity. The block heater will only heat the block to a certain temp and it will reach that temp in at most 3 hours.

As for warming it before you drive, again mostly fallacy. Warm it up enough to make sure you can keep your windows clear (for safety), start off at low rpm (don't race right of the gates) and within a few minutes you are good to do whatever style of driving you like. Your vehicle warms up much faster under a light load, letting it sit and idle doesn't have a large benefit.

RobHunter76
03-29-2010, 02:18 PM
I was told the same as Spaceman... better off driving slow... especially on newer engines. Something about them being designed for cold weather and intended to heat as they drive.

poe
03-29-2010, 06:10 PM
I like to try and let it warm up until the windows start to defrost. I also let the old dodge run in nutreal and not park so that the trans well warm up to. I learned that one after I had to do a rebuild when I took the tranny out. It was about -30 and I let my truck warm up for 20 min but it was in park. made it about 15 miles down the road and then she went.

redcrew71
03-29-2010, 06:46 PM
on my 2009 GMC work truck it has the digital tranny temp....it does not matter if its in neutral or park...it does not warm up any faster.....I let it idle for 15 minutes and it only went up 4 degrees....not until I put it in gear that it heated up.....slowly

DUKESTER
07-04-2010, 12:20 AM
After going full Synthetic, tranny,diffs, brake,motor, 60secs tops. :thumbs_upI don;t plug in.

saskmat
12-19-2010, 09:32 PM
after 3 hours you block heater is as warm as it would be after 20 hours. would not want start my dodge diesel after -15 with out bein plugged in

ldmann12
12-19-2010, 10:06 PM
the minus 17 from gm is not an engery thing it is a coolant temp sensor thing. if the air temp is above -17 and it is plugged in it will set a temp code and command the cooling fan on full and will reduce engine power. i see it all the time when cord ends get ripped off. as for letting them warm up they do need atleast 10 minutes for the oil to warm up and get rid of condensation in the oil. have seen oil pumps freeze do to moisture build up cause they are not warmed up proper and then not drove very far. hope this helps

JimiHat
12-19-2010, 10:28 PM
When I was in university one of my electrical engineering profs explained to us that for maximum efficiency the colder it is, the SHORTER the time you need to plug your vehicle in. :confused:

When you plug your vehicle in the block heater will warm your engine up to a point where it reaches a steady state (constant temperature). Once this steady state is reached you're not gaining any further benefit to having your vehicle plugged in.

When it's colder, the steady state temperature reached will be lower but it will be reached sooner.

I can just see everyone's eyeballs rolling back in their sockets. Maybe I'll have to draw a Time vs. Temperature graph to explain it better.

my eye's aren't rolling back, but I do want to see this graph. ;)

BowDawg
12-19-2010, 11:47 PM
Interesting thread....I run a 08 Dodge diesel, so i plug er in at about -15. If I don't she is pretty cold starting. I usually let it run for 30 min after starting before I leave for work. 45 min if it is really cold....;)

smokechecker
12-20-2010, 12:04 AM
I'll run my Dakota until the back windows begin to thaw.

mapman
12-20-2010, 07:42 AM
depends on how cold it is. A few minutes if it's below -15 and if the heat isn't out the vents yet i still take it slow.

It is reassuring to have the heat out the vents...froze a rad once and then blew the hose out on the highway in the middle of the night...should have clued in when there was no heat after 10 minutes of running.

BeerSlayer1
12-20-2010, 09:32 AM
my eye's aren't rolling back, but I do want to see this graph.

Sure, I can draw one out and scan it for you.

BeerSlayer1
12-20-2010, 10:20 AM
OK, here's the graph.

I think I explained it pretty well earlier, read carefully and look at the graph.

Originally Posted by BeerSlayer1
When I was in university one of my electrical engineering profs explained to us that for maximum efficiency the colder it is, the SHORTER the time you need to plug your vehicle in.

When you plug your vehicle in the block heater will warm your engine up to a point where it reaches a steady state (constant temperature). Once this steady state is reached you're not gaining any further benefit to having your vehicle plugged in.

When it's colder, the steady state temperature reached will be lower but it will be reached sooner.



http://i47.photobucket.com/albums/f153/BEERSLAYER1_2008/WarmingBlockHeater.jpg

This is the way I remember it being explained about thirty years ago by Dr. Madan Gupta. I see he's still around, appropriately enough he's one of the world's foremost experts on Fuzzy Logic. Not what you think...;)

http://www.medicine.usask.ca/research/health-research-groups/neural-systems-and-plasticity-research-group-1/group-members/madan-gupta/index.html