BimmerFest BMW Forum banner

1 - 16 of 16 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter #1
When ever I start my car after sittign for awhile, it idles at about 1,000 and will rev up to 1,200 and back down for the first 10-20 seconds then will purr nice, but sounds like **** untill then. Any quick fixed on this or is it a 7 series thing. Its a 2006 750Li with 52,000 miles.
 

·
Registered
Joined
·
37 Posts
I took mine to dealer for this problem, after they did "something" it has improved but not completely fixed. However they raised my IDLE by 50 RPM and now my car idles at about 550 rpm rather than about 500 rpm. My recommendation, take it to the dealer and after that get use to it.
 

·
Registered
Joined
·
51 Posts
I had that issue on my 07 with 20k miles.....took it to the dealer and had the master tech do a reprogram of some sort but it fxd the problem
 

·
Registered
Joined
·
1,663 Posts
I thought the first 20 seconds it was suppose to run a little high then tapper down to 500 at least mine does. Someone before here stated that its the air pump that causes it to run rough first 20 seconds or so. I would search but i wouldnt consider it a problem.
 

·
Registered
Joined
·
2,092 Posts

·
Registered
Joined
·
10 Posts
try this it's easy to do only 5 minutes and solved all your rough idle and check engine light problems on your (2000-2009) later or newer yes! all BMW E60, X3, X5, 325i,330i,335i,525i,528i,530i,535i,... check out the manifold adjuster Google this up.

That appears to have been the problem the whole time. This is what caused the check engine light and O2 sensor fault and misfire codes. listed below are the codes that are caused by a broken Intake Manifold Runner Valve/Adjuster Unit!!!

Ignore these codes after changing your broken or damage Intake Manifold Runner Valve/adjuster Unit these codes will be gone.

P0171 = Fuel Trim, Bank1 System too Lean

P0174 = Fuel Trim, Bank2 System too Lean

P0300 = Random/Multiple Cylinder Misfire Detected

P0313 = Misfire Detected Low Fuel Level

P0741 = Torque Converter Clutch Circuit Performance or Stuck Off

P1083 = Fuel Control Mixture Lean (Bank 1 Sensor 1)

P1085 = Fuel Control Mixture Lean (Bank 2 Sensor 1)

P1342 = Misfire During Start Cylinder 1

P1346 = Misfire During Start Cylinder 3

P1348 = Misfire During Start Cylinder 4

P1350 = Misfire During Start Cylinder 5

P1352 = Misfire During Start Cylinder 6

The adjuster's part description on www.ecstuning.com
Air adjustment unit controls the path of the air in the intake manifold, allowing either a shorter or longer runner length. A common source of trouble causing low RPM sluggishness and accompanied by a clicking sound from the engine bay. The exact symptoms.

Location on driver's side. I already removed the two T40 bolts (upper right and lower middle.) Then simply pull the adjuster unit straight back out towards you. ( 5 minutes)
After removing the manifold adjuster you can also clean your idle control valve (ICV). It's easy to remove the ICV 12 minutes job and clean it with the Throttle Body & Air Intake Cleaner!!!







I can feel the difference in the acceleration and there's no slight hesitation or engine rough idle and after clearing the check engine light it will not come back on!!!
 

·
Registered
Joined
·
313 Posts
Hmmm - I'm not sure this exists on the E65... Was looking around on realoem.com and couldn't find it for our car :( - I did find it for the E90 though. If it is this simple, I will definitely be looking into it!

Mine also idles rough at startup (when cold) and takes 15-20 seconds before it settles down. My impression was that the valvetronic takes some time to initialize. During initial startup my understanding is that the air intake is controlled by the throttle body (which is normally not used as air is controlled at the engine intake valves). However, this theory doesn't completely explain (IMO) why the idle isn't rough when I start the car again if it is still warm. When either warm or cold, wouldn't the valvetronic still need time to initialize...?
 

·
Master Tinkerer
Joined
·
2,218 Posts
Based on your description, the equivalent parts on the E65/E66 would probably be the throttle body (#1 here) or the part that shortens/lengthens the intake runners (#2 here). However, on the E65/E66's N62 engine there is a little more to it than just those parts -- for example, the differential pressure sensor (#4 here), not to mention the implications of using a valvetronic system at or near idle (very little vacuum, for example).

My point is that the 8-cyl N62 and 12-cyl N73 engines are very different beasts from the 6-cyl ones, and while that part is a good start, I think it's an oversimplification of the system as a whole.
 

·
Registered
Joined
·
43 Posts
My Dealer told me the rough idle, and sounding like crap for the first 20 to 30 seconds is a 7 thing, and they all do it.
 

·
Registered
Joined
·
1 Posts
my 2008 750li started the rough thing about a week ago. When started it this morning and left the check engine light is now on. Do you think I have to replace the Intake Manifold Adjusting Unit
 

·
Registered
Joined
·
3 Posts
I know that this is an old thread but I have similar rough idle problem with my 2002 745iL. Like I have read and understood the intake manifold adjuster fault doesn´t turn on the check engine light. So I think lcarreth must have some other problem.

DIS gave me two variable intake manifold faults. I cleaned the intake manifold and replaced the intake manifold adjuster. Fixed this problem but the rough idle isn´t totally gone.

After cold start when the engine runs at 1000rpms during the secondary air system pump operation for about 20-30s it drops the rpms to 700-750rpm and shakes a bit. Before I did the spark plug, coils, oil and filters change it dropped them nicly to 500. When the engine warms up after some driving the rmps drop to 500. Some rear times it rises the warm engine idling to 750rmps too.

Does anyone know what could be the reason for that?

Any help is appreciated
 

·
Registered
Joined
·
5 Posts
My 05 750 also does this when i start in the morning. I tryed unplugging the vannos but didnt make any difference. I unplugged the maf sensor an it will start and run perfect. Anyone have any idea?
 

·
Registered
Joined
·
5 Posts
Replaced the maf already no change
Also changed plugs and coils, the crank case valves in the rockers, checked for vacuum leaks ect
 

·
Finally got a 7 Series!
Joined
·
108 Posts
Hmm, my 06' 750Li does the same RPM variance but does not have a rough idle. I just hit 150,000 miles as well.
 
1 - 16 of 16 Posts
Top