Engine warm-up time

[MapleLeafMerc]

OK, this is a pretty feeble question, technically speaking. Yet it's something I've always wondered about.

Back in the days of carbureted engines, you had to let a car warm up for a while or they would stall on you (especially if you were driving an older/poorly tuned car). The problem was magnified in cold temperatures. Now with the wonders of fuel injection the quirks of carbs are gone, and so is that specific reason for warm-ups. BUT there's that thing I've always heard about start-up being the toughest time for engine wear, letting the oil circulate properly, etc.

So- is it possible to offer any kind of general statement about how much time should pass between the engine starting to run and when it is OK to put it in gear? This question nags me more during cold snaps like the one we're having now where it is going down to as low as -20°F. Sometimes I hear creaks and groans from the car when it's this cold that make me feel 'sorry' for it!

What about hard acceleration with a cold engine?

Would advice for the MM be applicable to most recent makes/models of cars and light trucks, and would or should the time increase as the temp drops?

[Fourth Horseman]

I've read that it's less wear-inducing to get your car going at normal road speeds and normal work load as quickly as possible. Letting the car idle in the driveway to "warm up" is said to actually be worse for the engine. I suspect that this is why our engines tend to roar upon start. It's probably programmed this way on puprose to get the engine up to operating temperature quickly.

[STLThunder]

I agree with Fourth Horseman, I was taught to start the engine, wait about 5 seconds and then drive mormally, but I usually wait until the engine has warmed up before any hard acceleration.

[greyghost]

Depending on how cold your motor is on start up let it idle 30 sec to one minute to ensure the oil is circulating then get it moving. No WOT acceleration until up to normal temp plus a few minutes to get the oil up to normal temp. Water temp will come up fairly quickly but oil temp will lag behind as it has the crank and block to warm up. This is just one persons assesment with lots of experiance

[SergntMac]

Me three agree. Start it and go. The program that revs the engine at start up will not allow much other than normal crusing until the engine reaches normal operating temp. Last winter, I timed it on zero and below zero days. 7 minutes of normal driving until the engine reached 180 degrees, and I started to get heat in the cabin. BTW, I understand the early morning groans, but letting the car warm un in the drive way won't do much for that. If you let it idle until the cabin is nice and toasty, you're actually doing more harm than good, and the MPG really sucks.

[Dr Caleb]

I can't say for the Marauder, but I let my CV idle 10 - 15 minutes in neutral if the weather is below -20C.

I find the motor hasn't come up to temp yet, but the oil is flowing and the tranny fluid has built up a little heat, making for smoother operation. Also helps clear the morning ice off the windows - less scraping. Just my $.02.

IIRC, someone here blew a motor when the just started her and went WOT, 5000rpm without sufficient oil flow. Our manual does reccomend not idleing to warm up.

[jfclancy]

Me three agree. Start it and go. The program that revs the engine at start up will not allow much other than normal crusing until the engine reaches normal operating temp. Last winter, I timed it on zero and below zero days. 7 minutes of normal driving until the engine reached 180 degrees, and I started to get heat in the cabin. BTW, I understand the early morning groans, but letting the car warm un in the drive way won't do much for that. If you let it idle until the cabin is nice and toasty, you're actually doing more harm than good, and the MPG really sucks.

Well when it gets that cold I always had a block heater and in line water heater plug 'em both in for a half hour or so before initial start up. Having spent time in Montana and Alaska this seemed to work best.
However WOT before complete engine warm up WILL kill engines. Esp in extreme cold.

JMHO
Joe Clancy

[Bigdogjim]

I have always waited 3-5 minutes before driving away at any time of the year.

It is best to keep vehicle below 35 MPH till engine is warmed up.

Back in the 60's & 70's I use to change plugs often because of somethimg called a high-speed glaze forming on the plugs.
I would start up and just go!!!!!
Times change

Like I said I always let them sit for a "few" minutes.

When it is cold, if you watch the tack the RMP's will drop after a few minutes. Then go

[jgc61sr2002]

IMO it is disiraible to start and go. The engine will come up to operating temperature faster while your vehicle is moving. Drive moderately untill engine warms up. No WOT.

[MapleLeafMerc]

Many thanks for all your replies. This shows again why I'm addicted to MM.net, because you can talk to friendly people about anything

[Mark McQuaide]

My last car, a Passat V6, had a 30-valve motor. The owner's manual specifically said not to warm it up at idle because it extends the cold running time, which is when you get the most wear.

Also to consider is emissions, they want you to warm up the car quick since they release most of the emissions when cold.

Like most of the people who responded, I start it and go, and drive gently until it's warmed up.

[dwasson]

Or just do like I do and let it sit in the garage until April.

[merc406]

Warm it up to suit your own body temp, I hate freezing behind the wheel.

[Marauderman]

[QUOTE= Also helps clear the morning ice off the windows - less scraping. Just my $.02.
[/QUOTE]

Well, I recommend what I do --I place cardboard over the windshield and held down by the wipers stopped in "mid-operation"---works everytime--no scrapping here...and as for the warm up time period--it's best summed up by saying to gently throttle till normal operation temp has been reached...which is about 7 minutes per Mac......I'd say thats about as good as your gonna get for that answer.............This place

[junehhan]

I usually start up the car, and let it idle at least 30 seconds, to a minute at most before I start going. I figure it's best to give it a little time for the oil to work it's way around before starting to move. From there, I use nothing but light throttle and keep the revs below 2500rpms until the engine has reached full operating temperature.