The air keeps cutting on & off by itself

4, two each on each bank of the exhaust

Not something you want to attempt on your own. I have 35 years working on these cars and I send the tops out.

try replacing throttle position sensor, usual suspect. but have it on a fault diagnostic machine to establish this. hope this helps and if you need any more info then dont hesitate to ask

hi there,

it sounds like one of three problems a faulty knock sensor/throttle position sensor/or idle valve sensor

sadly only way to know is diagnostic check up and see the fault code

Looks like your going to have to bring it to a dealer. There isn't much you can do to repair an air bag fault on a BMW without using an oem level scan tool. Most Independent repair shops won't have the equipment needed to diagnose it. It could run into big money but usually air bag faults are either sensors or the clock spring in the steering column. In either case, keep in mind with the air bag light on the air bag system is disabled.

The linkage has probably come undone. You can disengage the rear motor by pulling on an orange tether that is under the right passenger seat. Once that's done you can manually put the top up and down and check the linkage.

Sounds like the sensor has faulted or the pump has become disengaged. Usually when the light is flashing it's a sensor. You can check for a pinched line or low fluid also. There is a manual lock overide procedure to get the windows up, it's in you owners manual.
Good luck...i hope this helps,

I had the same problem and it was the airflow sensor that was on the way out. good luck

hello right have u had service done recently may be sh**y plugs check oil lvls and get her running with someone reving and unplug air flow meter se wht happens if theres no change in engine noise it prop tht otherwise take off air intake pipes etc check for blockages (very rare) i can also suggest common fault is pipe from air flow meter to the engine suffers dramaticly from lil cracks and alsorts check tht over completely and the hoses beneath it try all tht first if you dnt have any luck thn start thinking fuel filter alot of crappy fuel about nowadays but i rekon its your pipes either crackes of poped off let me know how ya get on

I dont know if im right but i think its a problem of oil pressure.