Do you guys recommend letting the engine idle down before driving off?

[LouG]

About cold starts killing cars.
My first house was on a very steep street. One of my neighbours had a new Nissan something that he used to just fire up and shoot off up the hill, no warm up.
Engine was f**ked in a year. I kid you not.
The rest of us had mechanical sympathy, our cars and bikes lasted.

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[steveo1960]

I let it idle a bit before taking off and I'm easy on it until it warms up. IMHO what I find even more important is to drive away and for the first few minutes, maybe 5 or so, NO music or anything else on. Why? Because you want to listen to the car. Listen for odd noises, sounds and such while you are still close to home and can get back to home base before anything gets ruined.

 

[Frogdog1]

About cold starts killing cars.
My first house was on a very steep street. One of my neighbours had a new Nissan something that he used to just fire up and shoot off up the hill, no warm up.
Engine was f**ked in a year. I kid you not.
The rest of us had mechanical sympathy, our cars and bikes lasted.

A cold engine will seem to put out noticeably more power for a short time as I think there is less friction because the pistons and cylinder walls aren't expanded to one another yet. Thus your neighbors outcome. He wasn't the sharpest knife in the drawer and paid for it as you say.

 

[robvas]

A cold engine will seem to put out noticeably more power for a short time as I think there is less friction because the pistons and cylinder walls aren't expanded to one another yet. Thus your neighbors outcome. He wasn't the sharpest knife in the drawer and paid for it as you say.

There's also more friction because the oil isn't warmed up yet

Also, wouldn't a non fully expanded piston seal worse and make LESS power?

Mustang7g, the source for old wives tales!

 

[Frogdog1]

There's also more friction because the oil isn't warmed up yet

Also, wouldn't a non fully expanded piston seal worse and make LESS power?

Mustang7g, the source for old wives tales!

Well, I think "no" in answer, not because there isn't oil friction, but because that friction is much less than less metal to metal fricion when cold. There are a lot of moving parts that need to warm up and mate better when proper heat is achieved, including oil viscosity friction so my statement was just based on my observations through the years, not a multi-million dollar govt. grant. Nothing scientific in my observations but a lot more "seat of the pants" feedback which we all know is more accurate than dynomometers of course.......

 

[robvas]

Is it easier to move your hand through cold or warm oil?

edit: this site has the worst text editor

 

[AZ_Ryan]

I've always let my cars idle down on a cold start before driving. I cringe when I see people start their cars cold and just throw in gear and take off.

 

[LouG]

A cold engine will seem to put out noticeably more power for a short time as I think there is less friction because the pistons and cylinder walls aren't expanded to one another yet. Thus your neighbors outcome. He wasn't the sharpest knife in the drawer and paid for it as you say.

True, he got into deer farming just before it collapsed.

 

[LouG]

Is it easier to love your hand through cold or or warm oil?

I'll ask my wife.

 

[ZXMustang]

This has nothing to do with oil temp or pressure. Its strictly and only to heat up the cats as quickly as possible. Spark is retarded to get the cats hot quick and the intake cam is also -30 degrees to increase EGR to speed up cat heating. This has not nor ever been about anything but heating the cats up as quickly as possible to lower emissions. This is called ""cat light-off". There is no benefit for waiting this out whatsoever - except to the atmosphere. Here is what you would see for both start up spark and intake cam. Once light off completes around 30 seconds (depending on starting ECT), the spark will come up and the intake and exhaust cams will be 0/0. Various other things happen as well like fuel pressure drops and airload as well.

 

[Zig]

1st start of the day in cold temps, I'll idle it until some heat is showing on the gauge. Otherwise I'll just let the fast idle reduce and go.
I'll never cane any engine until it's showing normal driving temps

But now the question, do we get aggressive with cold tires or chill just a bit until we notice a pressure increase?

 

[AZ_Ryan]

But now the question, do we get aggressive with cold tires or chill just a bit until we notice a pressure increase?

Another drunken post unrelated to the subject with a really obvious answer.

 

[Zig]

Another drunken post unrelated to the subject with a really obvious answer.

You can grab an go if you want, no skin off my chin.

Why would you let your tires warm but not your engine/transmission/rear?

 

[Junkyard Dog]

I pause only long enough to put on my seat belt and start up the podcast to which I am going to listen. It does no good at all to leave a cold engine idling. Plus, if it is very early in the morning, even on "Quiet" exhaust mode, the sound goes right through the house, and I figure if I drive away it is less likely that I wake up my sleeping kids.

I do wait for the oil to be over 180° before I drive higher rpm or hard. I kind of baby it until then.

 

[Junkyard Dog]

I'll add that the old "let it idle for 30 seconds to a minute to let oil circulate" has nothing to do with modern oil pressure and flow in an engine like the Coyote.

I was watching my hot oil pressure at 74 psi or so while driving at 2000 rpm or a little more and thinking, "Back in the old days my oil pressure would never get that high no matter how high I revved the engine.

Yeah, back in the 10psi per thousand rpm rule of thumb days, I let it idle for about 30 seconds to a minute, especially on the cars that had a choke (as those would die if you drove and the choke came off too early). On the "racing" type street cars with large carbs that had no choke, I had to leave my foot on the pedal a bit to keep the rpm up a little to keep it from dying at idle, and on cold days pump the pedal some to give the accelerator pump a work squirting extra gasoline into the venturi. Big cam, big carb, cold day . . . not a turn the key and go proposition.

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