Calling all e39 540 drivers

[P1000]

....I leave it to idle in the morning before I leave. That's probably why mine is so much more.

Why????
Just start up and drive off sedately.

+1000 Please don't idle it, it does no good, only harm.

 

[Nic_s]

....I leave it to idle in the morning before I leave. That's probably why mine is so much more.

Why????
Just start up and drive off sedately.

+1000 Please don't idle it, it does no good, only harm.

I don't let it idle until warm, only to get things flowing after which it's a super slow drive out the complex over speed bumps. I just figured that the time idled adds up and ruins my average consumption. Maybe the car needs a tune. I have no idea what the previous owners might have done to it. :dunno:

 

[andrewbuch]

+1000 Please don't idle it, it does no good, only harm.

My dad, During winter last year he was parking outside, So every morning he went out @ 6am with the car covered in Ice.. & started the car, let it idle for a while.. put the heater on max as front defogger & rear on..


Then got the hose out to get the ice off, so basically he idled the car for like 15 to 20 minutes :thumbdo:

 

[Sith]

Ok guys, please excuse my obvious massive ignorance here. I only let my car idle for literally 2 minutes, and only when I start her up the first time in the morning. Rest of the day is start up and drive. With that first morning start, the motor is a little rough, and it settles within those 2 minutes I let her idle.

So why is it not good to idle a little on that morning start-up?

Is it normal for the motor to be a little rough on that first start-up?

Interested in your responses, Thanks. :=):

 

[Budleigh]

Ok guys, please excuse my obvious massive ignorance here. I only let my car idle for literally 2 minutes, and only when I start her up the first time in the morning. Rest of the day is start up and drive. With that first morning start, the motor is a little rough, and it settles within those 2 minutes I let her idle.

So why is it not good to idle a little on that morning start-up?

Is it normal for the motor to be a little rough on that first start-up?

Interested in your responses, Thanks. :=):

I'd say that it should be normal. It takes a while for things to begin circulating and while cold, the gubbins will be at wider tolerances. The collective wisdom from M5board is that it should be fine if you should just drive off slowly and allow it to warm up to temp. Have the Peake codes read if you're overly worried.

---

....I leave it to idle in the morning before I leave. That's probably why mine is so much more.

Why????
Just start up and drive off sedately.

+1000 Please don't idle it, it does no good, only harm.

I don't let it idle until warm, only to get things flowing after which it's a super slow drive out the complex over speed bumps. I just figured that the time idled adds up and ruins my average consumption. Maybe the car needs a tune. I have no idea what the previous owners might have done to it. :dunno:

Nic, my consumption driving around Stellies (lots of stop-start) and robots settles on 16l per hundred, 19l if I power away from every robot, 23l per hundred if I drive like a bat out of hell. Your car doesn't have an inefficient box of slush transferring power to the wheels, so it should be more frugal. I'd have it checked out.

 

[Sith]

Thanks Budleigh, just what I thought, and have not been overly worried about it, but then, it is an M5. Thing is, why is it then not healthy to let her idle and warm up a little? Surely the 2 minute idle would be a good thing, and not damaging?

 

[Budleigh]

Thanks Budleigh, just what I thought, and have not been overly worried about it, but then, it is an M5. Thing is, why is it then not healthy to let her idle and warm up a little? Surely the 2 minute idle would be a good thing, and not damaging?

I think the conventional wisdom is that since the engine is running very richly at cold start up, so you're having unburnt fuel washing away the protection of your expensive oil. Maybe compromise and idle for no longer than 30 seconds? I doubt you'll kill it by leaving it for 2 minutes, but it's better in the long run to just pull away slowly and let things get up to temperature.

 

[dyllindd]

I think there must be something seriously wrong with my 2003 E46 318i.
My average is 14.4L/100km.

Could someone please help or just buy me a new car

 

[Wick-ed]

Wow!!! And next week fuel is increasing again by 20 odd cents. :argh:

 

[andrewbuch]

I think there must be something seriously wrong with my 2003 E46 318i.
My average is 14.4L/100km.

Could someone please help or just buy me a new car

Auto / Manual ???


Traffic / Highway ???


My E46 318i Manual currently sitting on 10.3 l /100km Average over the last 8 fuel ups..

But in pure town driving, If driven hard I can get it up to around 15l/100km

Our E46 318i Auto, was at about 13 to 15l / 100km when My mom drove it, When I drove it it shot up to around 17l/100km's

 

[Clownshoe]

Thanks Budleigh, just what I thought, and have not been overly worried about it, but then, it is an M5. Thing is, why is it then not healthy to let her idle and warm up a little? Surely the 2 minute idle would be a good thing, and not damaging?

I think the conventional wisdom is that since the engine is running very richly at cold start up, so you're having unburnt fuel washing away the protection of your expensive oil. Maybe compromise and idle for no longer than 30 seconds? I doubt you'll kill it by leaving it for 2 minutes, but it's better in the long run to just pull away slowly and let things get up to temperature.

Spot on. Mechanically an engine with no load is not a happy engine. I think they call it piston slap when the piston can have a certain amount of wobble in the sleeve. When an engine is cold the tolerances are all out as well so that makes it worse. Coupled with a rich mixture with the above results makes the cold idle the worst wear period for an engine. At idle you are also not warming the engine up terribly quickly either.

After chatting to lots of mechanical engineers about this I came to the conclusion the best cold start up sequence is: engine on, leave enough time for oil pressure to come up (oil pressure gauge helps) but i use the time it takes to get my ducks in a row before pulling off, like seatbelt on, stow cellphone, select music) then an easy drive at 3-4000rpm until the temp gauge starts picking up. Then wait till oil temp up to +60C before hammering it.

 

[Philip Foglar]

Thanks Budleigh, just what I thought, and have not been overly worried about it, but then, it is an M5. Thing is, why is it then not healthy to let her idle and warm up a little? Surely the 2 minute idle would be a good thing, and not damaging?

I think the conventional wisdom is that since the engine is running very richly at cold start up, so you're having unburnt fuel washing away the protection of your expensive oil. Maybe compromise and idle for no longer than 30 seconds? I doubt you'll kill it by leaving it for 2 minutes, but it's better in the long run to just pull away slowly and let things get up to temperature.

Spot on. Mechanically an engine with no load is not a happy engine. I think they call it piston slap when the piston can have a certain amount of wobble in the sleeve. When an engine is cold the tolerances are all out as well so that makes it worse. Coupled with a rich mixture with the above results makes the cold idle the worst wear period for an engine. At idle you are also not warming the engine up terribly quickly either.

After chatting to lots of mechanical engineers about this I came to the conclusion the best cold start up sequence is: engine on, leave enough time for oil pressure to come up (oil pressure gauge helps) but i use the time it takes to get my ducks in a row before pulling off, like seatbelt on, stow cellphone, select music) then an easy drive at 3-4000rpm until the temp gauge starts picking up. Then wait till oil temp up to +60C before hammering it.

+1

Same here, start the engine and drive off gently - I don't like having a cold engine sit idling for too long, so generally drive off as soon as possible, well, obviously let all the fluids get moving around. Only when really cold I might give it half a minute to accumulate some warmth.

Interestingly, my 330i has a clever oil/water heat exchanger which is designed to manage the engine temperature so that the engine can get up to temperature fairly quickly. Now, stupidly there is no temperature gauge, and you can only get an oil level reading on the electronic dipstick once up to temperature. If I drive off it takes a long time (longer than the E46 and even diesel bakkie) before I can get the oil level reading, but if the engine sits idling for a few minutes before I can eventually drive off, check for an oil level reading and it shows the oil level, plus the engine is now idling as it does when warm. I still drive off gently since the rest of the drive-train is still cold...

 

[dyllindd]

I think there must be something seriously wrong with my 2003 E46 318i.
My average is 14.4L/100km.

Could someone please help or just buy me a new car

Auto / Manual ???


Traffic / Highway ???


My E46 318i Manual currently sitting on 10.3 l /100km Average over the last 8 fuel ups..

But in pure town driving, If driven hard I can get it up to around 15l/100km

Our E46 318i Auto, was at about 13 to 15l / 100km when My mom drove it, When I drove it it shot up to around 17l/100km's
[/quote

Manual, town. No hard driving... Too scared of fines.

 

[Spy007]

I get decent cons on the Gopher. But then again drive a round with a glass of water and look again

 

[andrewbuch]

Manual, town. No hard driving... Too scared of fines.

By no hard driving, are you saying you never go foot flat?

What revs do you change gear at?

Is it lots of traffic? cause this would mean you idle for long time with no KM's

 

[dyllindd]

Manual, town. No hard driving... Too scared of fines.

By no hard driving, are you saying you never go foot flat?

What revs do you change gear at?

Is it lots of traffic? cause this would mean you idle for long time with no KM's

Never go foot flat and revs always between 2000 and 4000 max. Usually change at 3500.

 

[VictorMike]

car: 1998 540i steptronic
distance: weekdays: from elardus park to rivonia and back (about 80km round trip)
weekends: all over the place
drive: use the n1, and sometimes it is bad and sometimes it is good.
driving style: I am VERY cautious. I do not want anything touching my car, so I leave a BIG distance in front of me. Having said that I try to stay between 100/120 on the highway when it is bussy, and about 130/140 when it is clear.

consumption: 11.376 l/100

 

[///MALCOLM325]

I get around 12 -13l/100km mixed driving in my '00 E39 540 Steptronic.