Occasional hesitation on slight acceleration when driving

[johninoz2]

Originally Posted by yd_dc

johninoz2, did you replace the tranny and did it solve your pbm?

No didn't replace tranny - will probably replace my X5 before doing that. The vibration was not that often and as Diyanich noted earlier, it really does not happen in Sport mode or as I also find it does not occur under heavier acceleration so that's my cure for the moment. May result in less MPG but gives a little more FPG (Fun Per Gallon).

[HPIA4v2]

Originally Posted by johninoz2

Hi all,
Thanks to all on this site that have made owning my X5 more enjoyable. I hope someone will be able to give some advice on some occasional vibration I have been recently experiencing when slowly accelerating while driving slowly. I have had the vehicle minor serviced recently with no error codes present at the time of service. I notice that when the engine is warm and while in park, if I press the accelerator slightly and hold it the engine revs climbs and drops repeatedly about 200-300rpm. Though it may be due to a dirty MAF but when disconnected the engine does the same. Has anyone experienced this or know what could be causing this. Engine starts well when cold and accelerates good under heavier acceleration, fuel economy seems lower but may be due to me accelerating faster to avoid the slow acceleration vibrations. Is there anything I can try to see what may be causing this? My X is a 2003 4.4 Sport.

I have 02 4.4i with exact same symptom above, took it to dealer and since no code no fix. Did trans adaptation reset and no help.

My thought was the temp sensor in the transmission was going bad, but has not triggered any code but I wasn't going to replace parts at random.

Then.... my upper radiator hose cracked and leaking coolant badly, so I thought well @58K miles it's due to redo the cooling systems, WP, thermostat, Radiator hoses, serpentine belt, A/C belt and walla no more vibration, at least it's hella smoother and pulls harder with less vibration.

If I were you, try flushing the coolant first and see if it improves. I noticed that a couple of years ago when I did the coolant flush. I know it sounds weird but worth a try then you can decide if you want to rebuild the cooling system.

Oh BTW, I had to replace the trans oil cooler as well cause it was leaking coolant afetr my WP replacement just to be complete on my response here.

NOTE, I've been hunting this problem for a while, I even flush my tranny fluild with no affect to fix this problem.

[mysweetx5]

Themmmmmmmmmmmmmm you guys scared me to ever not want to own any Bmw's because I have this similar feeling sometime (a little skipping feeling on the gas pedal: like the car moved-up itself while slowing down on a stop sign.

[faxman14]

Looks lik I hav the same issue - it has been getting progressively worse and more frequent.

It happns at about 25-35 mph and at around 1500 rpms...not at higher rpms por sped or at least not noticeable.

Also sems worse when going up a light incline.

I was hoping it as something other than tranny.