To warm or not to warm?

[kwakdonut]

..by this i mean perhaps forget warming up as long as i do currently and just keep to low revs while moving off until warm, which in turn will make the oil spread quicker hence warm quicker than if just sitting there.

are we agreed?

Definitely. I understand you're still running in anyway, yes? I certainly don't 'cane' the car until it's warm!

 

[Bellow]

Long, cold morning idles for a petrol engine will cause excessive wear due to fuel wash on the cylinder bores (due to choke/cold start), whether carb or injection engine.

Not same for diesel engines as the fuel is an oil rather than a hydrocarbon solvent

Modern day petrol engines aren't jugging in the fuel like they used to. You won't get much bore wash, but you will see soot in the oil by driving on a cold engine if you do oil analysis. At idle, how much fuel is going compared to driving - it's a miniscule amount!

Diesel will still dilute oil if it gets a chance, to the detriment of film strength.

 

[Benjy]

Billy, as I stated before, each to their own. Explanations have been offered but if you wish to let the car warm a little first, then that's your decision. I don't think anyone is trying to force you to drive off straight away!

I am an engineer, both car and aeronautical and understand the principles of metal-on-metal wear!

Thanks for the heads up....as you can probably tell I dont have an engineering mind but have learnt a lesson and its only with threads and advice like yours that we learn a little more about these things. So thanks for this.

 

[kwakdonut]

Modern day petrol engines aren't jugging in the fuel like they used to. You won't get much bore wash, but you will see soot in the oil by driving on a cold engine if you do oil analysis. At idle, how much fuel is going compared to driving - it's a miniscule amount!

Diesel will still dilute oil if it gets a chance, to the detriment of film strength.

Yes, but the cold start will still increase the amount of unburnt fuel going in. The internal combustion engine still doesn't like cold weather!

 

[rizzer]

If its just cold I usually drive off straight away but I do let the engine warm up gently to start with. When its frosty I always leave it running until ALL the windows are clear before I drive off.

 

[DRBC43AMG]

Start car. Allow oil pressure to come up (approx 5-15 secs). Drive off!!

Also it helps if your car has heated seats, additional heater, lives in a garage.....

Exactly how I do it with all my cars, even those living outside. Currently one of them is buried under snow with temps way under 0°c. Going to dig it out tomorrow before more snow announced for Sunday afternoon and night

 

[Bellow]

You have to be aware of where the oil pressure is monitored, most likely near the pump. A good reading on the gauge is no guarantee of oil at the cams. Possibly it is giving the explanation for the lack of oil at the cams!!

 

[christopherwk]

I haven't got time to wait for the car to warm up, if the windows and lights are clear of ice, I'll just get in and go, obviously I'll drive gently - especially in this weather (not booting it) until the engine's warmed up - not that I go round floooring it anyway.

Even if there's frost/snow on the windows, I will not turn switch the engine on, and let it run - I will clear and clean the windows/lights first then, turn the engine on (wait for glow plug to go off first), and go.

 

[kwakdonut]

You have to be aware of where the oil pressure is monitored, most likely near the pump. A good reading on the gauge is no guarantee of oil at the cams. Possibly it is giving the explanation for the lack of oil at the cams!!

The sender for the 205 was in the cylinder head so as far as I was concerned, pretty accurate!!

 

[Tonison]

It sure helps the engine on the long run to wait a couple of mins for oil to circulate before driving off.

 

[steve333]

Start engine,turn on cd(+heated seats in winter)pull away-simples!

 

[gunning]

well i drive mine cold but i drive it below 2000rpm so that i dont boot it cold. Nothing wrong with driving it gently when its cold. But IMO on certain cars its good to heat them up before you go.

 

[steve333]

Never boot a car until it's reached normal running temp

 

[noogieman]

what to do when a car has been tucked away for winter and is being taken out in spring?
should I start the car, idle is a bit higher at start up, when it drops to 650-700???? rpm's then take off?

or

should I start the car, let her idle for 10 minutes so the oilpressure greases all the internal parts and the oil gets heated and then take off?

I have always let my car work on idling for about 10-15 minutes after a long winter storage!
Is this good or bad after a long slumber to let it warm up 10-15 min?


During summertime:
when I start my car first time in the morning, I let it idle for the higher revs, what is it about 30 seconds on higher rpm's and when the rpm drops to normal rpm I take off.
Is this good or bad for a car?

In Sweden there are laws to restrict unnecessary idling!
If you let your car on idle more than 1 minute, cops gonna bust you if you have bad luck!
Then you're on your way to court!

When on idle when waiting for green light, there's no restrictions about this.
This is about enviroment laws being restricted about unnecessary polution from diesel or gasoline vehicles

 

[Grahamcol]

I've always started car, fastened seat belt and then driven off after 5 to 10 seconds. However, if you leave it to idle for a few minutes in the cold weather first, some say this causes excess wear. I wonder whether it's true really. Yes, car will warm up quicker (measured in time) if driven straight away. However, the revs will be higher once on the move. Given this fact, and the fact that at idle the revs are much lower, I wonder whether idling to warm it up does as much damage as suggested ? In other words, how many actual revolutions does it take to make the car warm up with each scenario ?

 

[Tonison]

My point of idling for about 2mins is to enable a better circulation and lubrication of engine parts by oil that normally would have settled at the sump overnight.

 

[Black Slk 350]

Hi everyone. i start the engine,turn on heated seats set sat nav plug phone in then pull away that normally takes me a couple of minutes

 

[Tonison]

I do that too, but it's not the same if you didn't have to go through that routine.

 

[Olivier]

I start the car, put the heat on full blast and rev up to 1000 for a minute then 1500 for another minute and take off.
Can't see a thing before that anyway and the veg need a wee warm up...
I forgot, the viscious fan if off, way too cold for it...

 

[donubenz]

Hi, I am not sure about other manufacturers but Merc seem to take the hot water from the engine block directly. i.e. before the thermostat opens and water goes to the rad. My old 126 had heat from the heater within a quarter of mile from start. Had it been downstream of the rad it would have taken much longer. My old Minis used to take an age as all the water in the system had to be hot before you felt anything!
And yes I was always told to start and drive off straight away as an engine running at higher revs has more oil pressure to lubricate the motor and so causes less damage.