[BMW786]

I was reading in the owner's manual that you should not warm up the car and you can just drive off. I thought that was kind of odd, esp. in the mornings. Do you wait until you reach a certain RPM (i.e. 1000) before driving off or do you warm it up anyway? If a thread has already been covered on this, sorry, can someone point me there? Thanks.

[ZenDriver]

I start the car up as soon as I get in, then click my seatbelt in place and tune the radio/iPod so the engine gets a good 10 seconds to get it's juices flowing, then it's off.

Of course, DO NOT rev the car above 3-4000 RPM until the engine gets to optimal temperature, but feel free to put-put around till that happens.


Er... I should say, I "did" to the first paragraph. I rev the hell out of the Volvo because I despise it with every bone in my body and hope it blows up.

[JamieA]

LOL @ Zen

I had a beige Ford Meteor I despised once. Well the colour was actually called "Bahama Beige" whatever that is. Was left with it after a relationship breakup. I used to fantisise about smashing it into a wall. Tried revving it to death, but those Mazda engines they used in it were tough buggers... ahhh, the memories

[Nikki]

you don't really have to let the car warm-up unless it is cold out, I'd say below 40 degrees.

[JamieA]

Originally Posted by Nikki

you don't really have to let the car warm-up unless it is cold out, I'd say below 40 degrees.

I would agree with this one, doesn't the car have a special water pump that heats the engine super quickly anyway??

[Red]

Doesn't hurt to let the engine warm up for 30 seconds in any car...

[nrg09]

I would assume that with any car it is good to let the engine run for at least 30 seconds; let that oil circulate in there. Like I heard a friend of mine say "Starting your car up is the worst thing you can do to it----metal on metal" His statement didn't really make sense, but when you think about it he has a point

[E90Fleet]

Originally Posted by JamieA

I would agree with this one, doesn't the car have a special water pump that heats the engine super quickly anyway??

The ECU controlled thermostat stays closed so the engine heats up fast

Electrical waterpump can turn on or off as needed to make enigine fall in one of a number of operating temps depending on driving situation ( thats why you have no temp guage )

[Nikki]

Originally Posted by E90Fleet

The ECU controlled thermostat stays closed so the engine heats up fast

Electrical waterpump can turn on or off as needed to make enigine fall in one of a number of operating temps depending on driving situation ( thats why you have no temp guage )

interesting

[MCS]

No temp gauge is sort of annoying. I'm sure other current or ex-autocrossers/racers will agree. How will you know that the engine is in trouble if you're racing, wait for the smoke to pour out of the hood?!?

As for start up time, 10 secs can't hurt. I don't time myself from start up to go.

[longtran]

for all the cars i have own, i just take off as soon as i am ready too. no need to warm it up. its the same thing. i believe i saw this in my acura manual. i guess its all the same for all cars.

[E90Fleet]

Originally Posted by MCS

No temp gauge is sort of annoying. I'm sure other current or ex-autocrossers/racers will agree. How will you know that the engine is in trouble if you're racing, wait for the smoke to pour out of the hood?!?

As for start up time, 10 secs can't hurt. I don't time myself from start up to go.

It should warn you if its getting too hot

But imagine a normal person driving and your temp suddenly changes from 70C to 110C ( which is normal on N52 ) and then goes back down later. They will freak

[HRC]

I try to idle her for about a minute or so, then I'm off. Five or ten minutes later, I'm open with the throttle.

Danny

[JamieA]

Originally Posted by E90Fleet

The ECU controlled thermostat stays closed so the engine heats up fast

Electrical waterpump can turn on or off as needed to make enigine fall in one of a number of operating temps depending on driving situation ( thats why you have no temp guage )

That's right, you said in another post that the temp can move quickly and that would freak most people out... hence no guage.

I just plan to keep the car to low revs when I start off until I think it has warmed properly.

[Red]

Please explain why the temperature in the E90 would fluctuate? I find this interesting. I mean, what makes the engine different thatn any other?

[JamieA]

Originally Posted by Red

Please explain why the temperature in the E90 would fluctuate? I find this interesting. I mean, what makes the engine different thatn any other?

My understanding is that the difference is that the computer controlled water pump does not run constantly like it does on a normal engine. When the pump is stopped, the water left inside the engine heats up super fast. The pump can then run at a slow speed to trickle in cooler fluid or faster to feed it in fast if there is a need. Because of this the temp can fluctuate very quickly.

The upshot is lower consumption because the pump is electronic and improved engine efficiency because the aim is to keep the engine at optimal termperature all the time. This isn't possible with a conventional pump because it is powered by a pully attached to the engine and therefore varies output according to engine revs which is in the hands of the driver not the hands of a computer that understands exactly what collant requirements the engine needs at that point in time.

Normal engines try to approximate this - crudely - with the use of a termostat which limits cooling fluid volume during initial heat up to heat the engine quicker, then switches over to full volume when the temp is right. This aids warm up, but does not give the engine optimal cooling after that point.

Hope this helps.

[E90Fleet]

Originally Posted by Red

Please explain why the temperature in the E90 would fluctuate? I find this interesting. I mean, what makes the engine different thatn any other?

A higher temp is good for fuel economy( 112C ), a lower temp is better for power (80C )

Manufacturers have always chosen a middle value, but with the electric waterpump and thermostat the N52 engine can change its temp easily to suit the driving conditions

[e90fanatic]

you can just drive off....but make sure you don't stress your engine by going to 4000rpm+....just keep it under 3000 and u'll be fine....gas is too expensive to warm up...

[Red]

Awesome, thx guys.

[txusa03]

I agreed with 90Fleet. I can tell you all first hand I had the temp icon appeared on my display (yellow first then it turns red). This happend yesterda morning around 6:40. It really freaked me out because I could feel warm (not hot) air coming through the vent. The dealer checked and they told me there are two sensors in the engine compart that monior temp. They checked both sensors and found no problem with them. I think that the engine bay was too hot at that time and it trigger the sensors. It was like a nightmare when I saw the temp icon. I stopped into a parking lot and let the car sit neutral and it went away. I could not really stop on the highway but I did slowdown. In these car, the electric pump only activate when the engine is hot. So when you first start the car, the pump is not running so your engine heat up very fast so there is no need to wait (basically what e90fleet said). Sorry for the long story but though I should share my scary temp event.

[scottz5]

Just drive who has time to warm up?

[F32Fleet]

Originally Posted by MCS

No temp gauge is sort of annoying. I'm sure other current or ex-autocrossers/racers will agree. How will you know that the engine is in trouble if you're racing, wait for the smoke to pour out of the hood?!?

As for start up time, 10 secs can't hurt. I don't time myself from start up to go.

This has been argued for months, and here's my opinion. For those of u who had an E46, those temp gauges are bufferred in the sense they read cold, normal (between 2 ticks), hot/overheat. You E46 guys will remember the gauge always read in the middle although the actual temps flucutated up and down within the "normal" range. So technically this gauge was worthless.

The E90 also has temp sensors which will alarm you of pressure loss in the system and overheating.

My concern with the E90 is the potential for failure of the h2o/oil pumps. You'd think they tested these parts to the extreme and are requiring the upmost quality from their suppliers (It's BMW suppliers the make the parts afterall)