The engine management light(EML).
Some pics.You will get to these once you remove all the covers,engine and air ducts.

Powers1... Excellent as always. :thumbup:

Thanks for the pics.. I was looking at the right components by the looks of the pictures... Now, onto testing... :eeps:

Rob

I have done a test
 

Ok, we have some results.

Had travelled for over an hour. As soon as I got home, I disconnected the vacuum pipe from the EGR valve.

Went for a drive (so engine was hot from the drive home), included steep hills (I have a few around me) and general driving conditions.

What I noticed, was that the "truck" was more responsive, the engine didnt sound or feel as "rough" and it felt smoother. It didnt seem to have the hesitation or dropping/hunting revs after changing gears. The gears change swiftly, not like the slipping I mentioned a few posts ago.

I drove home, plugged in the vacuum pipe and went for an identical drive. The problems were back. The hesitation, the hunting of revs on gear change, less responsive and the engine seemed rough.

So, the verdict.

I dont have one.. Although I went on an identical drive, and there was a difference, Im not 100% sure if that is the actual problem. Sure, I could buy and install the new part, it wouldnt hurt (except my pocket), but I want to be 100% sure.

Powers1, the photo you show of the MAF is not the same engine as mine (I have the later one).

However, I think I found mine (and if it is, trust it to be so hard to remove, even to clean).

In the following picture, I circled what I think is the MAF. Can anyone verify it is and best way to tackle this? I mean, I might do the test Powers1 stated, but should I also try to clean it with CRC MAF Cleaner?

Thanks, Rob

http://i988.photobucket.com/albums/af9/rb0135/maf.jpg

RealOEM.com * BMW E53 X5 3.0d Hot-film air mass meter

I didn't quite read through the whole thread, but is this a cold start only behavior? Or the engine operating temperature doesn't matter? Cause a faulty MAF would cause issues no matter the operating temperature.

Hi Chas3.

No, it is only a HOT issue. When cold, car is perfect. Once operating temperature (hot engine) lack of power, revs drop after gear change, although accelerator in same position and a few other symptoms mentioned.

Thanks for the link and info on the MAF. I have been looking at Realoem trying to find it.

Rob

Got it. Kinda awkward that it doesn't throw any error codes on your DIS or INPA. It does sound like a faulty MAF, but for instance, a faulty injector could cause a similar behavior. I guess you could borrow one from a fellow 3.0d owner and see how the car behaves, to make sure this is the culprit, before you throw $100+ (at least in here) at it.

Thanks.. I wish it would throw codes (ones that would help I mean)..

I thought of injectors but they have been tested (by the mechanic that says to change the fuel filter as that is the problem) and people keep telling me if it was an injector, i should at least see some codes in DIS (the only codes I am seeing is from the NAV retrofit I did a few weeks ago and havent got around to coding that)..

The fact when I disconnected the EGR vacuum pipe, there was a noticable difference, could point to both being/becoming "faulty". I did read somewhere, a lot of people have had faulty EGR Valves on the X5 Diesels, after about 60K miles (100K kilometres) which I am up to 91K kilometres.

I might take both off and clean them out with the proper cleaning products and see if that helps.. I suppose that can hurt, and the MAF in the diagram from REALOEM is only held in by two screws. It might end up being a "quick" job. If the MAF was faulty, one would presume it would through a code???

Thanks, Rob

Oh well.. most are shots in the dark, especially without seeing the car. The simplest approach would be to run INPA and get some live data of the engine and gearbox if automatic, parameters while the erratic behavior occurs. Then you can go from there.

Regarding the EGR valve, it can get clogged even sooner then those 60k miles. Even if that is not the real culprit, I would clean it up anyway. As about the fuel filter, it usually causes a sluggish behavior only, not erratic RPMs; we change it at around say 10-15-20k km at most in here, due to awful diesel fuel quality.

MAF cleaning usually ends up with MAF damage. I would rather go the INPA way, then attempt to clean it.

Ok.. Thanks for all the info. :thumbup:

I think since the EGR showed differences, I'll start there (being the cheapest to get some carb cleaner and clean it). i will move onto the MAF after that.. better do one thing at a time, or I will never discover what fixed the issue (if I ever get it fixed).

Rob

Have you checked your glow plugs yet? I never saw that going anywhere above... I changed out my spark plugs and that got rid of the lurching issue almost entirely, throttle response seems better at lower RPMs, etc...

E