Engine warm up?

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imported_Devilsown

New member
OK, so I think I understand the whole concept of letting a engine warm up full if you can (drive 20 min) but I'm still kinda lost, so far I've gathered:

1. its less wear and tear on seals as the heat expands them and they contract when cold.

2. allows you oil to get to its correct viscosity

3. well thats about it really



I've also heard and read that its bad to let you car idle in your driveway for X time to let it warm up, I personally let my car warm up for about 10 min before I leave to work as I live about 5 min away. My wifes car (97 M3 ) says not to let it warm up and just to go. I've also been told otherwise, to let it warm up... So I'm kinda lost on the whole matter anyone care to help clear this up and explain why which method is better.



:thx
 
Its like a religion, so many view points. I wait until my idle drops from the high-fast idle, down to the lower (most cars around 1k). That takes about 20-30 seconds. I also don't put the hammer down until the car has really warmed up, just nice and gentle for the first 5 miles.



I love it when people tear out of my work parking lot on cold engines.
 
Thats the main reason right there, I'm the same as yakky. Once my RPMs drop to about 700~ I drive off. Today for instance the RPMs hovered around 1500 for maybe 45 seconds then dropped to 700.
 
You don't need to idle your car to warm it up, in fact this does more harm than good, well its wasteful. An engine under load will warm up much faster than at idle.
 
But on cold days you put extra strain on any component that uses oil as it thickens at cold temperatures. Hence why the RPM's are 2x or 3x the normal idle.
 
Candor said:
But on cold days you put extra strain on any component that uses oil as it thickens at cold temperatures. Hence why the RPM's are 2x or 3x the normal idle.
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I don't have that problem as my oil flows to -60F.
 
AeroCleanse said:
I don't have that problem as my oil flows to -60F.
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So tell us, which brand of oil doesn't get thicker when it gets colder. I'd love to see their spec sheets.
 
Is that old auto myth still around? I first heard that in the sixties. Let your car warm up for 20 minutes to protect (name your part). First, your gas mileage idling is zero miles per gallon. Second, modern cars don't need extended warm up. If they did, the car manufacturer would recommend it.
 
Devilsown said:
Yea me too, always see the nice blueish puff of smoke out of the exhaust from the oil burn when they do.
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I think I've had like 3 or 4 cars that have had "oil consumption issues" according to their respective forums. Somehow I haven't had those issues, makes me wonder how many people are flogging their cars when cold.
 
yakky said:
So tell us, which brand of oil doesn't get thicker when it gets colder. I'd love to see their spec sheets.
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I didn't say it didn't get thicker, I said it still flows at -60F. Any group IV synthetic can do this easily (in the correct viscosity).
 
My understanding is that if your car was built after the advent of computer-controlled fuel-injection, you should start the car, give it 30 seconds or so to let the oil pump get the oil moving and pressure up, then go. However, you should then drive gently until water and oil temps come up to normal levels.



Also, one of the biggest emission issues for any car is cold start, because the catalytic converter hasn't gotten hot enough to start doing its thing. The sooner you have the car moving and the ECU can go into closed-loop feedback monitoring, the better, IMO.



Tort

(not a mechanic, don't play one on TV, etc.)
 
This makes sense, IMO.



The car as well as it's componets (fluids etc) must warm up simultaneously.



Start car, let it idle for 20-30 secs or so, then drive off.



My e46M states in the manual to not let it sit and warm up.
 
My car idles long enough for me to fasten my seat belt and fire up the stereo. Then I drive easy until the temps start to climb. Engines warms up faster (as noted) under a load then just sitting. just shy of 150,000 miles on this lil 5.0 and she runs nice and strong. Used oil analysis showed all is well in my motor.
 
TortoiseAWD said:
My understanding is that if your car was built after the advent of computer-controlled fuel-injection, you should start the car, give it 30 seconds or so to let the oil pump get the oil moving and pressure up, then go. However, you should then drive gently until water and oil temps come up to normal levels...
Click to expand...



That's basically what "Click and Clack" said in the newspaper column a while back :xyxthumbs



I've never found any oil-consumption issues to be related to how we treat our vehicles following a cold start; a few of our vehicles use oil, most of 'em don't, and there's never been a correlation between whether we're consciously careful about such stuff (the Audis) or utterly dismissive to the point of borderline abuse (the beaters).



But I will say that we always take extra pains to not abuse forced-induction cars until they're warm (and we don't shut 'em off without a cool-down either).
 
i don't usually let my the engine warm up per say, but i just don't push it when the engine is cold. My car has a oil pressure gauge on it so that helps to know when the engine is at operating temp.
 
The first thing I do is start the car. The only warm up time is while I get buckled in, check the mirrors, set the tunes, that sort of thing. I just don't 'beat' on it until it comes up to temp.
 
One major factor is the temp. As the temp falls, the more need for some warm up. Not only for the engine but transmission/torque converter. I'm not sure what you guys are considering cold, but if you've ever started a car in -20 to -30C / -15F and started to move, you know it can't be good. Everything is sluggish and slow to react.



Block heater helps a lot, that's the little cord that runs out the front of the grill, for you guys down south.



Personally, block heater plug in at -15C/ 4F or below for a couple hours.



-40 and your tires are square.
 
Now that I think about it I think I should have added should one let it warm up for X time vs just driving and shutting you car off. Example my work is about a 7 min drive but just long enough where I really dont want to walk (dont trust the drivers here) So would one be better off letting idle for a bitt then driving to work or just going for it and shutting off you engine before its fully warmed up.
 
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