I am still busy working out some mechanical issues with my newly acquired '04 545i and I wanted to see if this SMG behavior was normal before I take it back in for a second round of service where they will once again look at the low rpm stability issue I have.

When I navigate my way though tight parking lots I can stay off the throttle if my car is moving and continue crawling along at ~5mph just as you could do in a traditional manual. However, this only works for a hundred feet or so at which point the clutch engages and I coast to a stop. Is this normal? If not I can see it being related to the rpm stability as the transmission may be thinking a stall is imminent which would make it excellent retort to my SA's claim that it the idle is 'in spec'.

 

Without seeing for myself, it's difficult to say for sure but my recollection is that the clutch will only disengage as the car slows down (before a stall, as you suggest.) In other words, if you're able to maintain a crawl without the throttle and not slow down, then the clutch should stay engaged. If the car slows at all however, the clutch would disengage as you describe.

Maybe someone who still has an SMG will chime in and confirm this...

 

I think its acting normally. If I took my foot totally off of the accelerator and came to a near stop the clutch would disengage. Possible if your idle setting is to high the computer might think your foot was on the gas. If I had my foot slightly on the gas the clutch would partially engage. It might be in that mode under your circumstance until the clutch gets hot and the computer stops the partial engagement until the clutch cools down again.

 

Good points pennetta...

 

I'll have to check... but if i remember correctly it doenst stay engage and let you roll using idle throttle like a traditional manual. I think the clutch engagement point is higher than the idle RPM speed, like 600-700 vs 850rpms or so.... I know you're saying that the car is still rolling and can still stay in gear but the programming of the clutch is more conservative, when you roll at idle speed you're at the MINIMUM point where the car will not stall and the car does engage the clutch before it reaches that minimum point.