In Reply to: 2nd gear sometimes holds revs (323) posted by JC on March 05, 1999 at 11:41:42:
When the cars are cold, the auto shift program holds the lower gears longer than normal to warm the cat converter up by forcing the engine to rev higher. You can fool it into shifting up by backing right off the gas, but this does make the car lurch a bit. It's a bit like driving in 'S' when you don't need/want to. All BMW autos fitted with converters do this in my experience. So it's an emissions reduction-driven phenomenon.
I'd rather it didn't do this, as it goes. The wear on the engine is exacerbated by low temperatures, and I can't believe the converter would warm up that much faster. Seems like a pointless bit of over-engineering to me, but who am I to argue with BMW's R&D?
: Sometimes I notice that when my revs are
: 3k or above in 2nd gear and then I try
: to shift to 3rd, the revs don't drop as
: quickly as the other gears do. This
: results in a slight lurch of the car.
: The car's only got 400 miles on it so I'm
: still taking it a bit easy.
: Can anyone tell me if this is normal? My
: other non-BMW cars ever did this.