Engine is halting?
 

check the mass air flow sensor. Unplug it and start it see if it makes a difference.

Thank you for the tip. I did it and now the engine is not stopping on low ODO but the overall experience a little bit worse. Anyway, it looks like it can be mass air flow sensor which is kind of sad because I replaced it 2 or 1.5 years ago. Any ideas if it is a sign that I have to replace it or there is some other options such as cleaning it. It is fairly new. Thank you again.

Same case as my 4.4X5.

As advised by my mechanic, rough idling was most often due to dirty or failed MAF sensor or leak in the intake system.
The engine stoppage on stops whilke travelling, is due to dirty intake valve (space during idle position is clogged with dirt/gum).

-clean the MAF with carb cleaner and dry with hair dryer. If still failing, replace with new.
-clean the intake valve with wd40, and wipe dry.

-replace with new, or clean and reinstall with silicon sealant the gasket of intake valve (o shape) and the gasket of the front flange (located in between intake valve and intake manifold).

-check for cracks on the intake duct (located between MAF and intake valve), and make sure the two small hoses attached to it are tight fit.

-check tigh fit of the small hose attached to the side of the front flange of intake manifold.


try it, it worked with mine. best of luck.

Thank you for a such descriptive information. I will do that. I'll let you know if cleaning will fix the issue. Is that ok to replace MAF Sensor with aftermarket one? Do the aftermarked ones well? The difference in price is quite big. It will be good to save some bucks. Please let me know if someone has a good experience with aftermarket sensors. I bought BOSCH last time and it seems did not live long anyway.

Where is intake valve can be found? Thank you!

I have hard time locating intake valve. I looked for it in here: RealOEM.com * BMW E53 X5 4.6is Intake manifold system

Perphaps, you are talking about the part that sits after MAF sensor tube in front of the intake manifold. The name of this part is Throttle Housing Assy.

RealOEM.com * BMW E53 X5 4.4i Throttle Housing Assy

I cleaned it but I want to make sure that I am not missing anything. Please clarify. Thank you in advance.

yes, TAH is what i was refering as intake valve.

don't forget about gaskets 11611729727 and 13547510433 as i have mentioned above. After reassembly, test your idling while parked and during stops. if everything went smoothly then you dont have to replace your MAF.

Just in case you have a problem with battery drain (very common problem of old X5), which could affect your engine performance, do as follows:

- check cables of sensors located at your wheels (all cable insulations deteriorated in mine and exposed the cables which some were already broken and in contact with metal - short circuit). i bought new ones and replaced all.
- remove your fuse for telephone (see under panel compartment).
- replace your FSR ( you need to do this if the speed of your AC fan is fluctuating).
- check lift gate light for plate number if with mud. If they are, replace the gasket of your liftgate.
- check your auxiliary fan if functioning (at radiator), if not replace with new (do not try to repair).


do the above before suspecting your alternator.

good luck.

My car looks like got back to the normal operation. The MAF sensor was very clean and looked like brand new. I cleaned it anyway. However, I think that the issue was with intake valve. It had a tiny level of dirt and dirty oil in there. I took it off and cleaned it very carefully. Today, I was able to drive the car normally. I hope the isssue will not get back. Thank you for all of your tips. I highly appreciate it.