2002 BMW M3: Cold Start

How cold was it that morning?

I wonder what the redline would be at -30 to -40 degrees like I remember growing up in Ottawa.

dragonflight, IIRC, the BMWs that I have driven with that feature(M3/M5/X54.6is) set the cold redline at 4000 rpm. What is more interesting is to observe how slow the oil temperature warms compared to the coolant temp. Even taking into account the buffered water temperature gauge, the oil takes two to three times longer to reach operating temperature.

The 09 RX8 has this feature now too. It's a really cool way to get people to give that little extra care on cold starts, when an engine is most vulnerable.

umm guys, those lights aren't just for the variable redline. i'm almost positive that the cold start RPM are is set at 6,000 or 6,500 RPMs. those same lights are used as shift lights in SMG equipped M3s

I have noticed a lot of newer cars will limit their rpm during a cold start. I know my aura does this in the cold and will limit the rpms when first started. The only difference is that the gauge lights will not change so you dont know exactly what the limit is.

It's very smart move...it doesn't take much engine revving to produce accelerate wear when the engine is cold.

Roadburner - You bring up a great point that so many people miss: Just because your coolant temp is "in the middle" does not mean your car is warmed up. It takes 10-15 minutes of DRIVING to warm up all the fluids in the engine AND drivetrain (i.e. transmission and, as appropriate, differentials). And "warming up" idling is not warming up at all, and it accelerates wear on the engine.

The proper way to warm a car up is to start it and, pending ambient temperature, begin driving it as soon as possible (I'll give it 30 seconds to warm up when the temp is below 60 degrees, and a minute when it's below 30 degrees). You want the car to warm up while driving as much as possible, once initial oil pressure builds.

The variable red-line is brilliant, and is on (I believe) all 2000 M5s and all 2001+ M cars in general (M-coupe, roadster, M3, and M5).

FYI for those on a slightly seperate topic: Many cars change fuel cut-off depending upon available oil signals (i.e. pressure or temperature). My Honda Civic SI will not go above 5800-6000 rpms if it has insufficient oil pressure....the pressure is needed to actuate the cam switchover.

Joe

"The variable red-line is brilliant, and is on (I believe) all 2000 M5s and all 2001+ M cars in general (M-coupe, roadster, M3, and M5)."

Yep - the last gen M5 was the first with this feature.

I think the new Cadillac CTS-V will have it as well - at least I know it has chaser lights for the redline.

my 99 VW TDI had a blue cold engine light. when lit you are suppose to keep the RPM down. I Like the variable RPM redline tach on the BMW...it's very practical and cool. All cars should have this simple....but useful feature.

Yeah...couldn't plug my car in once last winter, and still got it started (took a extra second or two though). The wierd part was the really stiff transmission; that took a little while to thaw out.

Jahfakin - My 2008 Subaru Legacy GT has a "blue light" showing the engine is cold that goes out after about 1 minute of driving...I also can't engage the "Sport Sharp" mode that essentially brings on full throttle at about 30% gas pedal input.

Nonetheless, it's not nearly as visible a reminder as a nice coloring on the tachometer :)

Joe

My S2000 automatically sets the cold start rev limit at 6500 RPM. There is no indicator however - unless the fuel cutoff and HUGE hesitation an indicator :) Strangely, my Civic Si doesn't seem to have one. Perhaps the newer technology means that you can rev hard earlier...

Change of topic..
What happened with the alternator swap? Why no response to the readers asking for a price comparison compared to an indie shop?
And what happened to the shim service at Summit? Still waiting on that?

Look at those gauges -- the classic BMW gauges were the best. Simple and elegant. The gauges in the Bangle Bimmers are less so, to my eyes. I believe the E46 Bimmers were the last series to get these types of gauges.
The variable redline tach in the M3 is just another one of the little things that makes the M3 so irresistable.

"Look at those gauges -- the classic BMW gauges were the best. Simple and elegant. The gauges in the Bangle Bimmers are less so, to my eyes. I believe the E46 Bimmers were the last series to get these types of gauges."

The E90's are very similar. They have a slightly updated look but are otherwise the same layout and orientation as the E46's. I actually prefer the improved legibility and cleaner, more classic look of the E90's gauges over the non-M E46's.

Dragonzsoul - those lights are BOTH for the variable redline, as well as shift lights in SMG-equipped cars. The cold start is set at around 4k or 4.5k, and increases as the engine oil warms up. The shift light is lit up as you approach 7.3k to 7.9k (depending on gear.)