E53 petrol fail safe again.

[X5smw]

Right… changed the throttle body, now goes like stink… 

didn’t start… new battery, now starts and goes like stink….

now drops into fail safe and says the idle valve is mechanically stuck open.

where is it, how much is it… can I kick it? 
 

 

[Greydog]

Morning Stu

Long time since I played with a straight six so the old memory might be wonky here so check realoem

From memory it is linked to the Air Pump and Vacuum control system. Find the Airpump and follow the Vac lines to the rear of the engine you should find a valve with a plug on top (or end) first make sure all lines are good no splits or cracks check the valve is operating, dont forget there is a non return vale in the system close to the inlet manifold. 

Hope this helps

Dave

[X5smw]

Right, changed it… it’s a bit of a faff, but basically remove the airbox and everything into the throttle body and there it is. 
took it for a run and all seems nice…

starts to come home and it suddenly goes into fail safe mode and loses all power again… 

gets it home and revs are all over the place. Computer says throttle position sensor Issue!.

I have already replaced the throttle body. 
I’ll take it for another run later. 🙄😩

[X5smw]

Update… took it for a run today and it did 30 miles without an issue… then the check engine light came on, no loss of power… got home and it’s telling me banks 1 and 2 running outside tolerances. 
put a new MAF sensor on which I bought this week. Let’s see what the next test run does! 

[X5smw]

Also noticed I have no headlight indicator on the dash now (blue high beam works) and the intermittent wipers have stopped! Lol

[Greydog]

Morning

Symptoms could point towards the Footwell Control Module or it's Earth point 

Dave