forever5

Are we talking diesel engine? If so, the rattle could be from a low cetane rated fuel. Try filling up and getting premium diesel from a reputable station; EXXON, Chevron, etc. Or add some cetane boost (like Redline diesel catalyst). Hope this helps.

Diamond

just cause you replaced your manifold doesnt mean anything. Could have had a defective piece in the new manifold-happens all the time that new or repalcement parts go bad again quickly-manufacturing issues etc.

Rasmus

Yeah, its a diesel. The preferred north european work horse. Here in DK Exxon, chevron is not an option... I will look at cetane boost...

Rasmus

True... If it was inded the swirl flaps, should it not be hearable in park idle or in park taking some rpm´s ?

Again thanks for all input!

Autobahn62

The problem with the disa valve was the inherent bad oem design.
Over time the flapper valve that holds the butterfly valve wears out, plastic u guessed it,
The replacement oem is not the solution as the same design flaw is not addressed, and this part will fail a swell.
I had a lean mixture and rough idle and my mechanic had a look at my disa valve. It almost came apart.
He suggested I look into the german auto solutions .com and I am glad I did.
I ordered and replaced the disa kit from these people.
It is simple DIY and it comes with complete instructions.
After replacing the worn out butterfly and flapper valves my car takes off from a dead stop. Like never before. No lean mixture too. The kit comes with with new silicone o ring. You carefully clean bad scrap out the old o ring on your disa unit and replace it with the new silicone ring.

dovla15

We're talking about diesel engines. 530d is very popular in Europe. If I was the first to check the injectors. They rattle in acceleration!
Hope this helps.
Cheers!