RPMs drop when stopping

Marceltj4.6is · #1 04-01-2010, 01:50 PM

Hey everyone,
Has anyone ever experienced the RPMs dropping very very low when coming to a stop? They kick back up but then the car jerks a little. Almost like the engine is about to stall.

Thanks,
MJ

X5Dawg · #2 04-01-2010, 01:52 PM

Yes, but I don't remember what I paid for to have it fixed.

Marceltj4.6is · #3 04-01-2010, 01:54 PM

Did they tell you what it was?

meltdown325 · #4 04-01-2010, 02:26 PM

I have the same thing, but it only seems to happen when decelerating slowly, almost coasting up to a stoplight. It feels like the trans is holding onto the gear a little too long before releasing, thus lugging the engine a hair below the normal idle RPM. Mine won't do it if I have it in Sport mode. No other problems, so I assume its just some manifestation of a glitch in the trans shifting software.

At first I worried about it, but now I just don't care about it. It does it every now and then, it has done it since I got the X, and 10,000 miles later it is still the same. I reached a point where I decided that I was just going to enjoy the ride. Cars will break whether you worry or don't worry.

digitaljok · #5 01-27-2011, 08:17 AM

Quote:

Originally Posted by meltdown325

I have the same thing, but it only seems to happen when decelerating slowly, almost coasting up to a stoplight. It feels like the trans is holding onto the gear a little too long before releasing, thus lugging the engine a hair below the normal idle RPM. Mine won't do it if I have it in Sport mode. No other problems, so I assume its just some manifestation of a glitch in the trans shifting software.

At first I worried about it, but now I just don't care about it. It does it every now and then, it has done it since I got the X, and 10,000 miles later it is still the same.

This is my exact experience with a 85k mi 2003 4.4 as well, but it has only started happening at maybe 80k. I agree that it feels like the transmission is not downshifting in time and thus drops below the idle RPM. But the problem is not consistently reproducible, so it will be hard to get diagnosed. I'm thinking of changing the fuel filter at around 100k (for the first time), wonder if that will have an effect if it's possibly fuel pressure related? Otherwise it may be even harder to pinpoint if it's a vacuum related problem. Any other updates on this issue?

meltdown325 · #6 01-27-2011, 01:03 PM

My X5 (2001 4.4) now has about 104k miles, and is still going strong as an ox. As I stated in April, my X has been doing the weird RPM drop occasionally since I bought the X with 85K miles.

I haven't noticed the problem getting any worse over the past 20k miles. I am almost certain that, at least in my case, it is not a vaccuum or fuel delivery problem. It does it so randomly, and never does it in Sport mode, which still leads me to believe that it is a tranny software/control issue.

I've moved on from worrying about this issue.