Short trips or long idles?

Let's say I'm taking a trip to the pizzaria. It's only 5 minutes away. Bad, bad, bad... So what if I leave the car on and go in? Worse, worse, worse? Or is it better that I'm leaving the engine running a little longer - making for a longer trip?

I've heard many times that idling is the worst thing for your engine...

letting ti idle for anything over a minute is bad , i remeber in alaska a gas engien that idled for long periods of time would end up haveing a higher occurance of gas in the oil (small ammounts) but none the less makes the oil not last so long

I think short trips would be worse.... But that all depends on how long your talking about idling it....

I personally think its a good idea to let your car warm up for 5 mins before you drive it..... I heard once that you do as much wear on an engine on a cold morning startup as you do on a 50 mile cruise......! Starting and going puts a lot of stress on the engine and tranny...

However, hot idling isnt good at all....

My auto teacher told us that it's good to rev it up a little when you first fire up the engine because it's at max friction when you first start it up in the morning so if you rev it up the crank balancers will splash the oil on the cylinder walls for extra lubrication.

My auto teacher told us that it's good to rev it up a little when you first fire up the engine because it's at max friction when you first start it up in the morning so if you rev it up the crank balancers will splash the oil on the cylinder walls for extra lubrication.

You should NEVER rev a cold engine at start-up, there is no oil in the cylender walls yet, and you are precipating wear! I read that 70% of engine wear occurs at start-up, so I wouldn't do it. When I was a kid, the old man that lived beside us was hard of hearing, and would rev the hell out of his brand new 1981 Impala. He thought if he did this it would warm up faster! Well his engine only lasted a couple of years and blamed Chevy for making crappy engines! You should have heard it, I have never heard a V8 scream like that and I hope I never will again.

I don't know where I heard it, but supposedly aluminum engines should be warmed up good before being driven. Does anyone know if that is true?

Hmm, thats not a bad trick.... Ill give it a try tomorrow morning.....

However, I think the engines do this for the most part already... When you start it up (using my car for an example) it goes to 1500 RPMs for a second, and then settles down at 1250......

Ralph........ I dont think he was talking about really revving it up... My take on it he was talking about like below 2000rpm (completely safe).....

I think you are right in saying aluminum engines need more time, because they expand and contract more.... But Sal has an iron block, so thats not such a big deal to him!

This is a really interesting story I found on the internet (well, someone found and posted it at the GAOC...)

Unusual mystery; why did this happen?
I have an 89 Pontiac 6000 STE with a 3.1 liter V6; it's an older car I
have owned for about, seven, or eight years. This car has about three
hundred, and fifty thousand miles on it. I use the car to drive to
where I work; as a mechanic at a Dodge dealership, because of its age
I don't have to worry about getting the seats dirty. When I bought
this car it had something like; forty thousand miles. I always
changed the oil on this car and flushed the radiator, since I got it.
Over the years, I have put 2 new radiators, a used transmission, 6 new
fuel injectors, and various sensors, and seals; the car doesn't leak,
and its never been burned up. A couple weeks ago, this car had a date
with the junkyard due to having a mutual low compression in all the
cylinders; between 70 to 90 except cylinder six. Cylinder six for
what ever reason, had over one hundred, this would cause the car to
vibrate while idling. I knew its days were numbered.
One day I went inside, left the engine running, forgot about
it, and went to bed. The next day I got ready for work when I
realized why I had no keys. I guess I'm lucky no one took it;
although I probably wouldn't have cared that much "Good Luck". When I
got in the car I noticed it was running perfectly flat, as I drove to
work I noticed a dramatic power increase, almost like someone replaced
the rings and valves while I was asleep. Now my lowest cylinder is
120. The only thing it could have been was sticky valves, but no
clicking was heard from the engine. Its been two weeks now, and I'm
shocked it runs like it did five year's ago, and all that happened to
it was I left it idle for eight hours. I know I'm getting rid of it,
and for a good reason, but my curiosity makes me want to take the
heads off it, and try to figure out why this happened.
I always thought I was really bad to leave a car idle at night
when you went to sleep, although the heater would always be warm. One
friend who is an engineer told me, leaving the engine idle for that
long, probably polished the cylinder walls off. This would make
since, because of mileage on the car, and the short trips; I'm sure it
could have used rings. I knew that was probably what was wrong with
it because it would run bad; until it got hot then it would run worse,
or so the rule goes.

Kind of strange; it should be dead. Did the apocalypse come while I
was asleep?

Wow. That's kinda fascinating, Rick.. Wierd...

I think short trips would be worse.... But that all depends on how long your talking about idling it....

I personally think its a good idea to let your car warm up for 5 mins before you drive it..... I heard once that you do as much wear on an engine on a cold morning startup as you do on a 50 mile cruise......! Starting and going puts a lot of stress on the engine and tranny...

However, hot idling isnt good at all....

On the other hand cars warm up faster when they're actually being driven, so letting it sit and idle for a few minutes is probably about as bad as it is to start it and drive off. Usually I just wait until the engine starts coming down from the fast idle. On fuel injected cars that's usually pretty quick, on carbureted cars it's a bit longer. Depending on how cold it is outside I'll let the car warm up enough that it's starting to blow out a bit of heat but if I'm going to be driving for a while I usually don't.

This is what I've been told by a number of techs. Later model engines ( Meaning late '80s To present ) are supposed to be designed to be run with a realitivly breif warm up period The supposed rule of thumb is to start it and wait till it's running smoothly and you're off. ( This is a very short time ) I'm not a big fan of this line of thinking but I've been told that it's way OK. I know that the new Heavy duty diesel engines are not as prone to damage without a long warm up as they used to be so it stands to reason that smaller automotive engines would be more tolerant of breif warm ups as well. As far as the question of extended idle periods....That's never been a good idea in any engine ( With a very few exceptions ) The modern heavy diesels have a fast idle setting so that you can keep the engine running for extended periods of time without damage due to low oil pressure and such. Automobile engines don't have this feature that I've ever heard of so it stands to reason in this case that you're not supposed to run them without a load source for very long. ( Engines are designed to be under a load ) It has never been considered a good idea to idle your car for very long. I read with interest ( And skepticism ) The earlier post about the high milage engine that miraculously cured it's own low compression issue by leaving it running. I rather doubt that it's a true story. ( Lies? On the internet?..Impossible! LOL! )

For about 4 months now, I've been letting my car warm up to about 150 degrees+ before driving. Anything below 120 degrees and I experience a fast idle. Once the car is warm, it drives wonderfully. Driving from a cold start makes my car mad....what's worse is that you have to brake harder due to the fast idle.

I'm thoroughly against revving or driving from a cold start thinking that's the best way to warm the engine; you can just feel the cylinders struggling to get toasty and lubed. IMO, the gradual idle process is the best way to extend the life of your engine.

For about 4 months now, I've been letting my car warm up to about 150 degrees+ before driving. Anything below 120 degrees and I experience a fast idle. Once the car is warm, it drives wonderfully. Driving from a cold start makes my car mad....what's worse is that you have to brake harder due to the fast idle.

I'm thoroughly against revving or driving from a cold start thinking that's the best way to warm the engine; you can just feel the cylinders struggling to get toasty and lubed. IMO, the gradual idle process is the best way to extend the life of your engine.

I agree with chuck that is acually what i do everymorning i start up my car and go back inside to pack my lunch and wait a while then go in ride is much better.

Interesting info. Plus, you supposedly get better fuel economy if it is warmed up a little. Interesting about the 3.1 Pontiac. We have a 2.8 Pontiac with a quarter million km's and I do notice a little less power. (compression loss?)

KC, if it's written in a book, it's gotta be true! :D :yawn:

KC, if it's written in a book, it's gotta be true! :D :yawn:


That's funny Ralphie boy! It's bullsh*t....But it's funny!

I usually start my car with the gas floored to the bottom; then just throw it in drive.. The wheels spin so fast that the car somehow flies backwards down the driveway. Once in the street, it hooks-up and heads down the road with no problem.

I let my cars warm up for about 30 seconds and then just take off and drive very easy until I get heat... Then I slowly start giving it more gas as time goes on...

:shocked2:

sal , that was hillarious man

I had to let my car run for 10 min this morning before i left for work... no cus i wanted it to idle... there was no way in hell i was gunna drive in a car that was 12 degrese!

hmmm, I just get in my car (when it is cold like now) start it up, let it run for about 30sec while I get everything ready and stuff, then drive.... although I am easy on it.... and you should never race a cold engine.... my friend had a '98 Mazda 626, 5spd, he would pretty much floor it the second it turned over, let it redline, then dump the clutch.....did that all the time...he had the car for 5months, it was a great car when he got it, then on Thanksgiving, he blew a rod right through the block.....

I would like to hear more about that guy with the 6000 and if anyone could support it or something....

I have a feeling that the guy with the 6000 could have had the same results with a few good redline runs!! It really helps keep the carbon out of there....

I agree with chuck that is acually what i do everymorning i start up my car and go back inside to pack my lunch and wait a while then go in ride is much better.

I'll bet the car thieves are happy to hear that..

I'll bet the car thieves are happy to hear that..

I hide in the trunk with my bat while my car warms up. This way any thief would wish they were never born when they see me.

hmmm, I just get in my car (when it is cold like now) start it up, let it run for about 30sec while I get everything ready and stuff, then drive.... although I am easy on it.... and you should never race a cold engine.... my friend had a '98 Mazda 626, 5spd, he would pretty much floor it the second it turned over, let it redline, then dump the clutch.....did that all the time...he had the car for 5months, it was a great car when he got it, then on Thanksgiving, he blew a rod right through the block.....

I would like to hear more about that guy with the 6000 and if anyone could support it or something....

Most days, as soon as I get to my car, there's at least one person that'll drive right up hoping to score my parking space. Sitting there for a minute waiting for the engine to warm up gets me the standard skunk-eye or the occasional middle finger!
Another good morning in the city....don't you love it?

We keep talking about cold morning starts.

What about starts after staying overnight during hot summer, when the mornings are not cold?

I think the short trips where your engine never has a chance to reach operating temps are the worse. You get piston slap and oil consumption issues. I don't think their is any harm in letting your engine idle for a long time other than the fact that some cars like to overheat or run hot. My sister in law lives in Fairbanks and says in the winter they let their car idle for hours at a time.

Interesting info. Plus, you supposedly get better fuel economy if it is warmed up a little. Interesting about the 3.1 Pontiac. We have a 2.8 Pontiac with a quarter million km's and I do notice a little less power. (compression loss?)

KC, if it's written in a book, it's gotta be true! :D :yawn:
I have a quarter million on my Blazer and when you give it gas, it makes a lot of noise and goes nowhere. Im considering letting in idle for an hour or two to see if it helps the engine after seeing that article im curious. Oh well, off to school for me.:bighead:

Sucks to be a Massachusetts person, no idle rule, biggest bullshit i've ever heard of.

Hmm, I've let my engine idle for rather long periods. I think 2 hours is what I accidently idle once. But that being said, i threw the heater on to get rid of part of the heat so the engine doesn't overheat, even though the fan does work. 111k miles and still no problems.

i think lettin ure engine compelty reach operating temp on a cold day is a little overboard...if i did that i would have to let it idle for 10 minutes each morning! so i start it and let it sit for 1 minute, then i easily give it very slight amounts of gas and i dont drive it hard at all and then in about 3 minutes the engine reaches optimal temps. honestly if people dont want wear and tear then simply just dont drive your car, as it ages wear and tear will happen no matter what.

Howyadoin,

Here's my rules of thumb...

1. Let engine idle until coolant temp reaches 100 deg. F.
2. Drive gently (<2500 RPM) until coolant reaches 150-170 F.
3. Don't romp on it (3000 RPM +) until 200 F.

If you let the engine idle until normal operating temp then take off, the transaxle is still relatively cold. It's better to just let the engine settle in and share some heat with you :) and then let the engine finish warming up while the transaxle does the same, without getting too aggressive.

YMMV, just the cacklings of a corvid...

I think idling is worse. My dad's job has him outside all day and in the winter he would sit in his car (93 Park Ave) with the engine running and heat on for long periods of time. The oil became filthy in no time. I make lots of little trips and I don't see any ill effects on my car.

Any of the modern engines, aluminun or otherwise, are best off if started and driven gently. There is no need to sit and idle and "warm them up". Hop in and go...just be a little gently on it the first few accels....that is all that is required.

Letting it sit and idle to warm up and get better fuel economy is counterproductive....You waste more fuel letting it sit and idle and warmup than would ever be offset by driving it warm only....

About the only rational that makes sense to let the car sit and idle for warmup is for creature comfort...i.e...to get the heat working.....LOL.

Short trips where the engine never completely warms up are much much harder on the engine than long trips. If you short trip the car every day it is a good idea to take it out on the expressway at least once a week and warm it up thoroughly to give the oil a chance to reach operating temp and purge any moisture and gas from it.

Engines will basically idle forever. Idling really doesn't hurt them. In the past, with engine driven cooling fans, engines would tend to run warm at idle due to low airflow thru the radiator (low fan RPM at idle....) but with electric fans the air flow at idle is great and most any car will idle forever regardless of the temperature. It really isn't going to hurt the engine or anything.

I have an 85 pontiac 6000 at home and those 2.8's will run forever if taken care of.

"My sister in law lives in Fairbanks"

good to see someone else has lived up there , she military ?

and yes cars do idle for huge ammounts of time up there , used to be a big theft problem because of that

I have an 85 pontiac 6000 at home and those 2.8's will run forever if taken care of.

I have a 1980 Pontiac Phoenix coupe with the first-year 2.8, and even if they were abused (raced) they lasted forever! Mind you I always did oil, and tranny changes. It has a quarter million kms and running strong! It seems to get more power and fuel economy from Champion plugs, and it's not worth putting anything expensive in, like plats. 150 ft. lbs of torque moves it just fine. ;)