warming up your car..., its a bad thing Options

[macavely]

Ok I over heard some guys talking about how they have to warm up their cars. There isn't many things i know, but one thing i do know for sure is, warming up a car is a bad thing. Car engine belive me or not were never made to sit idle.

[97sccelica]

[SpedToe169]

You're correct that it's not good to idle a gas engine for a long time, but 5-30 min to warm it up is totally reasonable. I wouldn't leave one idling overnight like you would/could with a diesel. Warming up isn't critical in most stock engines because they're made to be abused and driven before they're warmed up properly. An engine should be warmed up for a number of reasons. First off the oil viscosity changes very rapidly as the oil heats up from ambient to about 170deg. During this time oil flow is not as it was designed from the factory as it is many times more thick. Secondly, the clearances in an engine are very tight. As the motor heats up it undergoes thermoal expansion of all its parts. Different materials expand at different rates with changing temp. Engine builders know this and design engines so that the tolerances are optimal at operating temperature. Running an engine too hard while its too cold can damage it due to metal to metal contact and improper oil flow. It's always good to let your engine warm up for a couple minutes before taking off, but its usually not necessary on todays automobiles. Race motors are the exception. Running a race motor hard without FULLY warming it up (oil temp around 220-240) WILL almost certanly destroy it.

Sorry for the novel, just wanted to clarify.

[boosted_K2]

and your arguement y that is would be?? not saying i completely disagree with you, im just asking what's the phyics and reasoning behind this?

QUOTE (97sccelica @ Sep 17, 2003 - 12:31 AM)
QUOTE (macavely @ Sep 16, 2003 - 9:58 PM)
Ok I over heard some guys talking about how they have to warm up their cars. There isn't many things i know, but one thing i do know for sure is, warming up a car is a bad thing. Car engine belive me or not were never made to sit idle.


that's true, it is best for the engine to always be under load and constantly cruising.

if all cars were treated like that, then engines would never die, but this isnt a perfect world.

but have you ever noticed how crappy the engine runs when cold? no power and bad response. the car runs better with all the fluids up to running temp


which is why you warm up a car, to get the fluids up to temp before putting too much load onto the motor so it wont have a rapid temperature change, which stresses metal over time and makes it brittle and crack.


QUOTE (SpedToe169 @ Sep 17, 2003 - 12:32 AM)
You're correct that it's not good to idle a gas engine for a long time, but 5-30 min to warm it up is totally reasonable. I wouldn't leave one idling overnight like you would/could with a diesel. Warming up isn't critical in most stock engines because they're made to be abused and driven before they're warmed up properly. An engine should be warmed up for a number of reasons. First off the oil viscosity changes very rapidly as the oil heats up from ambient to about 170deg. During this time oil flow is not as it was designed from the factory as it is many times more thick. Secondly, the clearances in an engine are very tight. As the motor heats up it undergoes thermoal expansion of all its parts. Different materials expand at different rates with changing temp. Engine builders know this and design engines so that the tolerances are optimal at operating temperature. Running an engine too hard while its too cold can damage it due to metal to metal contact and improper oil flow. It's always good to let your engine warm up for a couple minutes before taking off, but its usually not necessary on todays automobiles. Race motors are the exception. Running a race motor hard without FULLY warming it up (oil temp around 220-240) WILL almost certanly destroy it.

Sorry for the novel, just wanted to clarify.


bingo.

all hail the moderator quadruple post... lol this was actually totally by accident... so ill condense it and make you people happy

[aaronc222]

The reason I blew my first engine(well, only one I really blew myself, the GTS already had a blown head gasket) was not letting it warm up. I hit the highway before the needle was even touching the gauge part. Of course it was in KS in the middle of winter(15 degrees out), but I learned a very important lesson. The valve springs were too cold and broke free of the rocker arm, causing the stem of the valve to 'tap' the valve cover. Luckily I got out of it cheap and learned my lesson on a crappy Hyundai.

Between the clearances, fluid viscosity, and even variations in electrical charge between cold and warm, it's always best for the engine to at least give it 30-45 seconds before taking off(I always wait untill the needle is at least above the 'C'). Even if you don't let it warm up, at least give it time to circulate the oil back into the head(when the car is off it all seeps back down to the oil pan).

If warming it up was a bad thing, then my 7AFE would be toast by now. I've put 102k on it myself, and bought it with 89. That's 191,000 miles without a mechanical problem. And it still runs as strong as when I bought it. Sure it has to due with my maintenece schedule as well, but warming it up always helps.

[Benevolence]

I always let my car "warm up" whether it be a summer morning for 30 seconds or a winter morning for 5 minutes, I try to let the oil start going throw before I move the car an inch.

[macavely]

i guess i should have made myself more clear.. i don't mean starting your car for 30 seconds then taking off, by warming up the car i meant letting it run for 30 minutes. Back in the day people would let the engine warm up not because of oil but because the gasoline would freez up in the carb.. but thanks to those beautiful people at exxon they started adding stuff to gasoline in the winter so it wouldn't freez.. ask any gas station owner (in a cold area) if he gets a diffrenet mix of gas in the winter and summer.. as for the oil well unless your in -degree weather its made to start up and run fine in cold weather..

[FallenHero]

My corvette would't go over 3kRPM's(electronically governed) until the water temp guage was over 200 degrees. Just a random statement.

Jon

[aaronc222]

[Andason]

Imagine drinking very cold water after having hot chocolate. Not a bright idea. The engine needs to have a suitable temp. before going off into cold. I live in WI and we know all about the cold.... were already hitting 40 degrees (to us this isnt cold).

[van95st]

the best thing i ever bought was an auto start!!!! try driving a car imediately after starting when it's been sitting over night @ -40F not only will you start eating engine parts rapidly, it's just down right uncomfortable, those seats turn into a brick.