XSeries-forum

Madly in love with my X5, its fantastic and so the car that I have always wanted. Its doing 2 pretty weird things though,

1 - intermitant knocking sound from the front, this is not somthing i can make happen it just does so at times. Any ideas?

2 - after pulling away quickly the gearbox seems to go into neutral rev hard ( as its auto and my foots on the gas thinking its going to carry on ) then bang into gear. This has happened twice, its more embarrassing than anything but am worried my gearbox is on the way out.

As always thanks in advance for any input, maybe someone else has had the same issues.

First one could be any of the suspension mounts or bushes under the front. Several folks have changed them on here. If it's a regular 'click-click' noise then it might be a drive shaft CVJ and can usually be replicated if you drive the car in a circle in one or other direction on full lock.

Second one needs keeping an eye on. It could be early signs of a clutch issue. You could try an adaptive drive reset which takes 30secs or so to achieve.
1. With the engine off and car in 'P' turn the key to Pos 2 (warning lights on, but engine not started).
2. fully depress the throttle pedal and hold it there for at least 30secs.
3. Release the throttle.
4. Switch off, then start the engine and drive normally.

It may not make any difference, but is the easiest thing to try. If that doesn't work then the next thing to do is take the car to an Indy with the right kit, or to a Dealer and get the fault memory read out for the whole car. That will give you a pointer as to what to look at next. Hopefully your worries will be unfounded.

Going to go try the adaptive drive reset now.

I have a great indy that has owned x5's and loves them so I think hes pretty up on them..

Mate thank you for the advice <3

So the drive reset did give me an engine managment light after the first go. I did it again and the light went off. I can also confirm that since doing this ( 10 days ago ) i have not had a single problem with the auto box. Thanks for the fix.

As for the noise..... well I did notice it getting worse and worse, it was so bad 2 days ago that my lady told me not to drive it cus it sounded scary. I drove it... 150 miles and no noise, Took it to the garage and my indy asked me to take him for a drive, could i replicate the noise? No :S Sods law. He then put it up on the ramp and started to look for any play in the parts around the sus. Nothing nothing at all. Drove to work this morning and again had no noise. Beats me but i guess its not all that serious if its not doing it anymore.

Cheers for the help people x

I had this but not as bad as yours and my Indy checked gearbox software which on my 05 model was 05 software. After update completely different box. Feels much smarter and no more weird changes. Would recommend to anyone having issues. Won't fix everything but good starting point for the cost.

As for the knocking sound, try your drop links on the front suspension, very difficult to test whilst on the car as they are constantly under tension from the arb and strut, but once removed, ( which takes no time at all ), you can soon see if the ball joints at either end are worn, this can give you noises from front to back as you're driving.
As has been said, the gearboxes seem to have a mind of their own sometimes, but usually a lot better with a reset or updated software, it's when it makes no difference you have to start worrying.

My old 7 series suffered intermittent knocking sounds depending on road surface . Could never find any fault nor could local garage .
One day the penny dropped that anti roll bar links resist body roll so I rocked the car side to side and there was the knocking sound .
I then had a helper rock the car whilst I observed the links and sure enough I could see free play in the ball joints .
You can always disconnect to check as weirdfish says .
It`s usually the lower ball joint which fails so the new replacements can be turned after 15 - 20 thousand miles to extend the service life .

As for the reset thing
I read somewhere about older bmw systems clearing certain fault codes and adaptation errors if you simply leave the ignition switch at position 2 ( ignition lights on ) for 30 seconds . Pressing the accelerator at the same time like you have tried may or may not reset more stuff but this does work for most folks. The info I read was some official bmw stuff which did not mention anything other than simply leaving ignition on for 30 seconds .