Try soaking the MAF in an alcohol solution. I experienced the same, and
put the MAF in a Rubbing Alcohol solution for 30 minutes. ($1.99 for a
liter bottle) and all was better... This was over a year ago.

I experienced very erratic RPM aswell. The engine took a very, long time
to come down in RPM.

On Thu, 13 Sep 2007, DCA wrote:

> My E39 530d (2001) started to behave sluggish tendancies
> symptons:
> very slow response to acceleration
> power reasonable at 1/2 throttle, dire at full throttle
> significant loss of power above 3750 rpm
> better performance when engine cold.
>
> I disconnected the MAF - the symptoms improved. Diagnosis: the MAF had died.
>
> I sought an OEM replacement for my Bosch 0928 400 468 airflow meter.
> Result: part number has changed to 0928 400 527 and cheapest was £175 + VAT
>
> Looked at far Eastern alternatives on eBay - got scared off by mixed
> experiences (see my previous post)
>
> I decided to buy a Pierburg alternative which is just the insert (no housing)
>
> Once I had sourced a security Torx bit, the replacement was a doddle (2
> screws) and required very basic DIY skills.
>
> Result - it is now A1 again and the cost was £61 delivered with VAT.
>
> I'm sure they make the alternatives for other models too - my recommendation
> is they are well worth a try and they are reassuringly made in Germany.
>
> I hope this saves someone else time and money.
>
> David
>

--
Joseph - Join the Auto Repair Wiki
http://www.FixExpert.com