[ON325i]

I have heard about idle-ing the car to warm up is not necessary. I agree with that too.

However, how long should we warm up the car by driving softly before we can kick in some high rpms?

I have been driving around yesterday night (-23C....) softly for 5 - 10 minutes. For some reason, mebbe just being my own worst enemy, I thought the engine does not sound the same when I rev from 3k all the way to 6k. There seems to be some resistance or not as smooth as usual. Mebbe it is just my worries of something broke down...

*worried*

[LEDZEP]

One of the things I miss is an engine temperature guage. I have always waited until the needle begins to move (indicating that the thermostat is open and hot water is flowing) before turning on the heat. Now I just guess and turn it on after I've driven a couple miles.

Depending on how cold it is outside you should probably not rev the engine too high for several minutes or miles. Wish there was a damn guage!

[SCA]

Originally Posted by LEDZEP

One of the things I miss is an engine temperature guage. I have always waited until the needle begins to move (indicating that the thermostat is open and hot water is flowing) before turning on the heat. Now I just guess and turn it on after I've driven a couple miles.

I miss the temp guage too, as I did the same thing in my E46.

[stack]

If you leave the heater in auto you will notice it only turns the fan on when the engine is warm. I always warm the car up a little because i don't want to sit in the cold car.

stack

[e90fanatic]

Just turn on the car for 30 seconds and go...the temp gauge on the E46 and any other cars are useless. It's the water temp, not the oil temp. The M3 has the oil temp and I think the new one will definitely get it too. Just drive under 3.5-4k rpm until you reach the first 10 miles of the trip.

[LEDZEP]

Originally Posted by e90fanatic

Just turn on the car for 30 seconds and go...the temp gauge on the E46 and any other cars are useless. It's the water temp, not the oil temp.

Yeah, we know it's the water temperature. Why does that make it useless? Water temperature is a good indicator of engine operating temperature and always has been. That's why there has always been a guage for it, as opposed to say.. exhaust temperture - which would be useless.

As the engine warms up, the water in the block heats. As the water heats to a pre-set temperature, the thermostatic valve opens to allow the water to flow through the radiator for cooling. The sensor in the water system passes the approximate temperature to a guage in the instrument cluster. The driver is hearby able to accertain that the engine has begun to reach, or has reached operating temperature.

Before cars began using the hot side of the A/C compressor for heat, this hot water from the cooling system was the sole source of heat for the passenger cabin, and thus it was good to see the temperature guage before turning on the heat (unless you enjoy cold air blowing on you in the winter). I have always waited until the temp gauge began to move before turning on the heat. I hate using the A/C for heat if I can help it... unless I'm trying to defrost icy windows or something.

[E90]

I fully agree with Coreslogic about the temp meter.In cold climate you need it.I have installed in my car a Defa heating system which uses 220volts and it then heats the engine and inside the car.It is a heating block installed under the engine to heat it with 220 V.Then there is an adaptor for connecting a heater inside the car to keep the windows clear.On front of our houses in the parking places we have a system where have a socket for 220 V.

[fredtoo]

Originally Posted by stack

If you leave the heater in auto you will notice it only turns the fan on when the engine is warm. I always warm the car up a little because i don't want to sit in the cold car.

stack

Heated seats rule! Heat in about 1-2 blocks.

[Bimmerista]

Originally Posted by LEDZEP

Yeah, we know it's the water temperature. Why does that make it useless? Water temperature is a good indicator of engine operating temperature and always has been. That's why there has always been a guage for it, as opposed to say.. exhaust temperture - which would be useless.

As the engine warms up, the water in the block heats. As the water heats to a pre-set temperature, the thermostatic valve opens to allow the water to flow through the radiator for cooling. The sensor in the water system passes the approximate temperature to a guage in the instrument cluster. The driver is hearby able to accertain that the engine has begun to reach, or has reached operating temperature.

Before cars began using the hot side of the A/C compressor for heat, this hot water from the cooling system was the sole source of heat for the passenger cabin, and thus it was good to see the temperature guage before turning on the heat (unless you enjoy cold air blowing on you in the winter). I have always waited until the temp gauge began to move before turning on the heat. I hate using the A/C for heat if I can help it... unless I'm trying to defrost icy windows or something.

From what I understand, since the water cools the oil which cools the engine, the oil temp varies because the oil pump is electric, which means the oil is pumped only as required, not continuously, so the oil temp is no longer an indicator of engine temp. since it has time to cool oof between uses.

[voltron1011]

Originally Posted by Bimmerista

From what I understand, since the water cools the oil which cools the engine, the oil temp varies because the oil pump is electric, which means the oil is pumped only as required, not continuously, so the oil temp is no longer an indicator of engine temp. since it has time to cool oof between uses.

The water pump and oil pump are electric. The water pump pumps water through the engine (through cavities) and radiator (to be cooled again). The water pump operates at various speeds so that there is no need for a thermostat. The water pump only pumps as much water as needed to keep the motor at it's optimal temp, whereas before the thermostat used to close/open a valve to the motor. The lack of a thermostat was the main reason (IMO) that there is no reason for a temp gauge. Before, you knew that your thermostat was going bad when your temp guage was always cold (meaning the thermostat was usually stuck open). BMW has removed alot of variables out of the cooling equation. Variables that would only cause problems. Now, if the electic water pump fails, you get a nice alarm on your dash (or Idrive) that tells you to pull over right away. Back in the thermostat days you didn't have that luxury. Also, how many of us have had a traditional water pump falure right at the drive pulley, where the bearings seized up. That won't happen on our E90's because it is completely sealed.

[ON325i]

an update: today, i run around town for 20 minutes or so before I
go M mode, and do a 1st 7k -> 2nd 7k -> 3rd , not another unusual rpm noise again. (smile on my face afterwards of course)

i guess for yesterday, either.... i didn't warm enough or it was just my imagination worries..