BMW E46 320D Losing Power

square ball · 30-09-2014 11:49pm #1

Hi guys. Sorry if there is already a thread about this.

I bought a 2003 BMW SE 320D last week. The car had seemed to be running fine until I was driving on the motorway. I tried to accelerate past 80MPH and car suddenly lost power and barely had enough power to stay at 60MPH with my foot to the floor. The next time I turned it on the power had returned and was fine again until I went back on the motorway. Same problem again as I went to accelerate past 80MPH again. At the next roundabout I turned the car off and on again and the power was back once again.

No lights came on in the dash and no smell from the engine and I don't think there was any smoke from the back either. Car had swirl flaps removed and new breather put in by previous owner and only done about 6,000 miles in the past year according to the NCT cert.

I really would appreciate any help or info on what to?

cock robin · 01-10-2014 10:37pm

It's just the car letting you know your breaking the speed limit, which is 120kmh (75mph)

Wheelnut · 01-10-2014 11:28pm

One possibility is that the turbo is over-boosting and this is being detected by the ECU which puts the car into "limp home mode". Switching off the ignition cancels this signal so the car is back to normal at the next start. The over-boost could be caused by a sticking actuation lever.

burke027 · 02-10-2014 10:03am

Is it a auto r manual firstly

square ball · 03-10-2014 11:23am

Cheers lads. Manual. showing up a few fault codes. 4521 manifold pressure sensor, 4507 exhaust gas recirculation and 4530 charge air pressure control.

Wheelnut · 03-10-2014 1:13pm

square ball wrote: »

Cheers lads. Manual. showing up a few fault codes. 4521 manifold pressure sensor, 4507 exhaust gas recirculation and 4530 charge air pressure control.

Could be turbo over-boost alright!

square ball · 03-10-2014 4:31pm

How would you fix it?

BMW E46 320D Losing Power

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