[Rhidium]

I had a debate with my father in law about whether we should let the BMW warm up before driving or not.

Practically every car I've ever owned for the last 30 year, I've never let the engine warm up (unless it's close to below freezing). All those cars (Lexus, Honda, Toyota, Volvo, etc) have run over 5-10 years without major issues.

He said that I have to treat the BMW differently and it's better to warm it up.
I'm just curious what your guys take on it.

[TajoMan]

All cars need warm up.
HOWEVER, warm up does not mean idling sit.
Engine warms up much faster if you drive on the road.
Just don't floor the gas pedal for first 4~5 minutes.

[SROC3]

I start....idle for 1 minute and drive off.

[titomi]

+1. Exactly.

Edit: +1 for TajoMan. There's no need for idling.

[AnOldBiker]

Originally Posted by SROC3

I start....idle for 1 minute and drive off.

X2 on this. I let the oil circulate then drive reasonably for a couple miles before getting on it. Been doing this on every vehicle I've owned the last 53 years without problems.

[teaston]

Originally Posted by AnOldBiker

X2 on this. I let the oil circulate then drive reasonably for a couple miles before getting on it. Been doing this on every vehicle I've owned the last 53 years without problems.

You would also have had no problems if you just drove straight off! There is definitely no need to idle the car to warm it up.

I calculated you have wasted around 2 weeks of your life idling your cars!

[AnOldBiker]

I didn't say until it warmed up .. I said I let it circulate the oil for a minute.
There is a major difference in the amount of time to accomplish both.

[pierreye]

I just make sure the engine is not rev above 3K rpm for the first 5 mins.

[ep22jg]

I drive straight off (unless I need to remove frost!) and take it easy until warm. Then when water gauge gets to temp, drive a bit harder, but never full bore until I think the oil is up to temp

[MechX3M40i]

Originally Posted by ep22jg

I drive straight off (unless I need to remove frost!) and take it easy until warm. Then when water gauge gets to temp, drive a bit harder, but never full bore until I think the oil is up to temp

I do exactly the same, drive straight off but take it easy at least in the first few minutes, until temp gauge indicates engine is warmed up enough.

Just curious - shouldn't the oil temp gets up to operating temp before coolant temp gets to 'normal range' and not the other way around?

[ep22jg]

AFAIK the oil takes quite a bit longer to get to temp. The water gets to temp really quick, which is down to things like active grills and electric water pump etc. This must help the oil temp too, but don’t know how long it actually takes?

[supersebbo]

I'm not sure on this... oil conducts (gains and loses) heat better than water, as the oil is flowing through the same parts of the engine block in theory it will heat up faster, but it will also lose it's heat faster back to the metal of the cold sump.

So really it depends where the oil temperature is being measured, it will be considerably cooler in the sump than in the core of the engine. Water retains more heat, so will be hotter as it flows out of the engine, but never hotter than the engine itself.

So in summary, whatever temp the water is coming out of the engine, the oil in the engine will be hotter than this. However that doesn't mean ALL the oil is at this temperature.

I have these gauges set up on Bimmerlink. I'll try and capture some real world data.

[supersebbo]

Oh and for the record. My tactic is not to go over 3000rpm until the dash gauge (whatever sensor that is actually read from) reaches the 'normal' band.

I did once take a friend to have his recurring BMW engine problem fixed at a respected BMW independent, when the car was ready I waited in the parking while he drove it out the garage, he immediately floored the throttle and fish-tailed out onto the road. The mechanic came running out the garage and saw me, ran over to my window and said "tell your friend that doing this on a cold engine is probably why the problem keeps coming back and also tell him I don't want to service his cars anymore"

[tastes jigga]

I think you are supposed to drive it immediately (within 30 seconds) in order to warm up the drivetrain, but avoid high RPMs and high throttle until the engine/oil warms.

[MechX3M40i]

Originally Posted by supersebbo

Oh and for the record. My tactic is not to go over 3000rpm until the dash gauge (whatever sensor that is actually read from) reaches the 'normal' band.

I did once take a friend to have his recurring BMW engine problem fixed at a respected BMW independent, when the car was ready I waited in the parking while he drove it out the garage, he immediately floored the throttle and fish-tailed out onto the road. The mechanic came running out the garage and saw me, ran over to my window and said "tell your friend that doing this on a cold engine is probably why the problem keeps coming back and also tell him I don't want to service his cars anymore"

LOL - I don't blame the mechanics... wonder if your friend also did something bad to the mechanics before that

[Radar314]

It is always warmish here. 70 to 90 degrees. I give it about 5 seconds to get the oil moving around before I put it in gear. Also gives a moment for any problem to show up. Kind of an old habbit.

[MechX3M40i]

Originally Posted by supersebbo

I'm not sure on this... oil conducts (gains and loses) heat better than water, as the oil is flowing through the same parts of the engine block in theory it will heat up faster, but it will also lose it's heat faster back to the metal of the cold sump.

So really it depends where the oil temperature is being measured, it will be considerably cooler in the sump than in the core of the engine. Water retains more heat, so will be hotter as it flows out of the engine, but never hotter than the engine itself.

So in summary, whatever temp the water is coming out of the engine, the oil in the engine will be hotter than this. However that doesn't mean ALL the oil is at this temperature.

I have these gauges set up on Bimmerlink. I'll try and capture some real world data.

I have the same thought about the oil temp...

On a related topic, my impression is that modern synthetic oil should be functional (i.e. providing adequate lubrication) even when cold, and excessive high heat is a worse enemy to oil (viscosity break down) than cold temperature. In the old days, conventional oil might have trouble providing the proper and sufficient lubrication since it's viscosity is too high when cold... Having a warm engine has more impact to better fuel combustion vs. oil lubrications. Look forward to hear from anyone who knows more on this topic...

[MechX3M40i]

Originally Posted by Radar314

It is always warmist here. 70 to 90 degrees. I give it about 5 seconds to get the oil moving around before I put it in gear. Also gives a moment for any problem to show up. Kind of an old habbit.

I think it's best to wait a few seconds like you do for the car computer to get up and running properly too! There are reports out there, and I experienced something similar, the backup camera or Nav might not function well immediately after starting.

[jjrandorin]

I voted "warm up" because of the definition of "warm up" given by TajoMan .

I get in the car, and drive straight off, however I drive very moderately until the car is up to temp. No hard acceleration, etc. I do (on my 435 I did anyway) put the car in sport mode before I even drive off, since I liked the throttle response in that mode.

I just drove moderately until the car was warmed up. Put another way, I get in, drive off, and drive like I am driving a camry or accord for the first 4-5 minutes until the car is warmed up.

So, I guess thats " I warm it up" but i have not ever sat and idled a car, ever.. which is why I dont get some of the angst about things like remote start. Of course, I live somewhere where its almost never cold by the definition of most of the country, AND my cars live in the garage when at home. They deserve to be inside just like me (lol).

[calintexas]

My 2010 M3 (Naturally aspirated 4L V8 9 quarts 10-60W full synthetic) didn't have a water temperature gage, but it did have an oil temperature gage. Normal oil temp ran between 200 to 220 deg F. Driving it moderately (under 3K rpm, light throttle) it took 3 miles for the oil to get to 160 deg F where I started using the power a little bit more and another 3 miles to get to 200 deg F. While we have less and lower viscosity oil, it's still prudent to drive moderately for the first few miles so that everything is up to temperature before you really use it.

[supersebbo]

Just did a test with BimmerLink. It looks like oil temp (however it’s measured) lags coolant temperature by about 4 to 7 degrees Celsius.

At start the coolant was 31, oil 26.
After 2 mins coolant was 47, oil 43.
After 5 mins coolant was 68, oil 62.
After 7 mins coolant was 75, oil 70. (This is when the dash gauge showed ‘normal’ - I.e it reached the middle)
After 10 mins coolant was 84, oil 77.


Also- am I going crazy or is it not possible to add attachments to replies in this forum?

[MechX3M40i]

Originally Posted by supersebbo

Just did a test with BimmerLink. It looks like oil temp (however it’s measured) lags coolant temperature by about 4 to 7 degrees Celsius.

At start the coolant was 31, oil 26.
After 2 mins coolant was 47, oil 43.
After 5 mins coolant was 68, oil 62.
After 7 mins coolant was 75, oil 70. (This is when the dash gauge showed ‘normal’ - I.e it reached the middle)
After 10 mins coolant was 84, oil 77.


Also- am I going crazy or is it not possible to add attachments to replies in this forum?

Was the oil temp measured at the sump?

As you said earlier, the sump can be a heat sink with about 5 quarts or so oil there...