Warm up time during winter
 

How do you guys know the X is warm to drive during winter? I always used water temp gauge on my e53

Any tips?

Wait 15 seconds for oil pressure to stabilize, and go. Any longer trying to warm it up at idle is bad for the engine. Best is just to drive it moderately until the oil is warm (not the coolant).

The manual says the best way to warm it up is to just drive.

just tap the redline a few times right when you pull out of your driveway to get her all hot and bothered.
Just kidding. x2 on start her up, wait a few seconds for the oil to circulate, then just drive easy.

Fire up car, put on seat belts, turn on heated seats, take sip of coffee, and drive away. The best way to warm up a car is to drive it.

My X is warm enough to drive as soon as the seat heater has my seat warmed up.

:iagree:

:iagree: start and go, keeping RPM at around 2000 for some time.

1. Agree about a short (15sec-1min) period of only idle prior to moving off. Put you phone away, sip coffee, turn on the audio, whatever

2. I discount the manual due to the fact that the recommendation is not based on what is best for your car, but is based on a composite of factors including pollution/green factors. A car idling in the driveway for 20 minutes is a polluter, and a responsible mfg should discourage.

3. However, idling the engine will not warm the tranny adequately, and hence you can warm up the engine - looks hot, right? yet the tranny is still relatively cold. You can inadvertently abuse the tranny in this situation.

So I guess I'd say 'warming a bit and driving is good'...and 'letting it sit is also OK, but the drivetrain is NOT fully warmed in this way'

Way to complex a discussion for a BMW manual though... especially now that BMW has no way on the diesel to measure engine temp. Idiots.

A

When manufacturers first recommended against idling an engine to warm it up, in the 1960s, pollution controls weren't on the horizon. It was better for the engine whether or not we cared about pollution. That is still the case today. Yes, an idling engine pollutes, but so little that it is hardly measurable. The engine damage is far more significant than the pollution IMO. So to discount a recommendation because it is believed to be somehow 'green' even though it is demonstrably better for your engine seems wrong to me.

Agree that the transmission will not fully come up to temperature just because the engine is warm (which it won't do by just by idling, but we've covered that). The transmission is heated, however, when cold. It does get warmed by the coolant via the heat exchanger. To me the larger issue when trying to warm an engine up while stationary is that all of the seals and moving parts are cold, throughout the vehicle. The transmission is about the only one that gets any heat.

I'd also note that if one is deciding the engine is warm by looking at the coolant gauge, then one is not measuring engine oil temperatures. The oil being warm matters much more than the coolant being warm.

What is amazing to me is that there is still a widespread belief that idling an engine to warm it up is somehow being good to it. It is fully 50 years since manufacturers published in owner's manuals that that is not true.

But you need to know "the rest of the story," as the radio comentator use to say.

Back then almost all gasoline engines used carburetors, not electronic-controlled fuel injection. As a result, at idle speeds with a cold engine and the choke on, you would get a "washing" effect from the overly rich mixture of gasoline on the cylinder walls.

Obviously, that is no longer a concern with today's precise fuel injection.

So whatever the recommendation was back then, it really has no relevance to today's engines, one way or the other.

I agree that washing down cylinder walls was a risk back then.

However, a number of SAE and other technical papers that documented the effects of engine and oil temperature on engine wear using test engines (with no fuel wash effect) were being published in the 1960 - 1962 time frame. They were strictly focused on how much wear happens with a cold engine vs a warm engine (more) and whether it was better to warm the engine with no load (which took an extended amount of time) or whether it was better to apply a moderate load (with moderate revs) so as to reduce the duration of the warm up cycle. They found that it was better to apply load as soon as the engine had oil pressure, and that the time effects (extended time at cold engine temperatures) were more damaging than the load effects.

So obviously fuel wash could make it worse, but the 'drive it immediately' recommendation would apply to fuel injected engines as well. And diesels.