Dear Gents,


A quick introduction from a new user; I am based in lovely Amsterdam - the royal kingdom of the Netherlands, and have a weak spot for rugged young timers with large engines. Furthermore I'm keeping close track of what the Pistons are doing on the opposite side of the Atlantic and hope to buy a King Tiger one day for it's off road capabilities. Lastly I am taking my first steps into maintaining and fixing my car, and this is why I'm asking for your kind assistance. Thanks in advance for any feedback you can provide to solve the issues my car is having.


The car: 05/99 European E39 540i touring, automatic, left steer, 242.000 KM on the clock.
(Battery 1 yr old, MAF 80.000 KM old, alternator 2 yrs old, ABS module 1.5 yrs old)


On a side note: ABS/DSC have been on for a couple of months, and speedometer fails most times. I am aware that the ABS module needs to be changed (it would be number 3, so I'm not in a hurry anymore). Pretty sure it's the ABS module, as I temporarily used a 740's module and the lights went off.


The issues started to arise after pushing the accelerator past the kick down a certain day, and the car instantly responded with a engine fail save message. After a stop and instant start, the message went away, and I was able to continue my journey. Ever since this happened, the car seems to have all kinds of issues. I already fiddled around a bit, so I will talk you through the issues after engine fail save, fixes and results and lastly the current situation. Perhaps also good to know that the battery was empty about a month ago, as I listened to radio for about 4 hrs with interior lights on while working on the car.


Issues after fail save:

  • Engine starts to stutter and car does not accelerate well when pushing the peddle quite quickly to about 3/4th before the kick down;
  • Stuttering happens mostly above 3000 rpm, and the transmission seems to have trouble shifting upwards (gear 3 to 4 & 5);
  • Car seems to have trouble shifting from gear 4/5 to 3 when I try to accelerate more aggressively;
  • The auto transmission sometimes shifts gears quite roughly between 1st/2nd gear at lower speeds (50 or lower);
  • The car runs pretty rough when idle at a cold start and the engine sometimes stops. RPM's fluctuate between 200-1000 RPM from time to time during the first 5 minutes idle running after a cold start; (car sometimes shaking pretty badly);
  • Car runs pretty smooth when I don't accelerate too heavily and stay below 3000 RPM;




Fixes and results:

  • -Too many codes to read, but MAF sensor code was one of them;
  • Code reset, MAF sensor code still visible after a 2 km test drive;
  • I cleaned my MAF > no change, still the same issues;
  • I fitted a new MAF > positive change and car ran fine after a 150 KM trip (smooth, good acceleration, didn't try kick down);
  • Next morning (continuous rain during the night) the engine would quit a couple of times at a cold start and issues seemed to have gone worse (more stuttering at idle, trouble staying on when lowering speed to about 20 KPH or below;
  • Battery light flickering from time to time when the stutter appears after I brake to reduce speeds to (30-0 KPH);
  • "Self Leveling Inact" message appeared while driving, and stays on after a couple of stops/starts;




Current situation:

  • Fitted the old MAF again > engine runs smooth at higher speeds and higher RPM when the engine is warmed up (+3000 RPM / kick down no problem);
  • Far less stutter at a cold start;
  • Gears change normally again upwards and downwards;
  • Engine consistently has trouble to keep running when I lower my speed to 20/30 KPH to stop for a traffic light for instance, and battery sometimes flickers with power steering loss during this process (no additional warning lights);
  • "Self Leveling Inact" message disappeared;
  • TEST 9 shows 11.7/8v at key position 1, 11.5 at key position 2 and 13.7/8 while running idle or when driving. Voltage doesn't drop when I activate the lights, radio, wiper, etc in all key position scenario's;
  • I continuously monitor voltage while driving, and there's a consistent drop in voltage from 13.7/8 to 12.3 or lower when I start braking to come to a stop. This goes hand in hand with the engine stuttering/stalling as mentioned above.
  • Engine temperature is spot on (max 108c);
  • At 15L or less fuel, all fuel is in the right part of the fuel tank, which would point out that the fuel pump is working correctly;




I wonder if the solution is just matter of changing the battery or alternator, or more a matter of changing a sensor (lambda, camshaft, still the MAF) or changing all of the above.


So gentlemen, this is the best I could do in terms of explanation. Feel free however to ask additional details. I'm not able to have someone read the OBD codes on short term, so I hope that's fine for now.


Muchos gracias!