Hi guys,

I own a BMW Z4 3.0i. There has been a rattling in the engine bay and there is a definite hesitation when i floor/accelerate the car...call it a lag maybe. On observation i realized it was the DISA unit which sits alongside the engine.

'Differentiated Intake System'.

Basically it is a valve that varies the effective length of the induction system depending on the engine speed, load and ignition switch position to obtain an improved torque over a wide speed range.

On the differentiated intake system there is a connecting valve between the intake pipes. This is closed when the engine is turning at low speeds to create high torque due to the long intake distance. When the engine is turning faster the valve opens - to produce a short intake distance and therefore more torque and power.

It adjust the airflow from what i gather...

Anyway, I took it to a very reputable BMW Independent. The head mechanic told me to keep it unplugged if it was bothering me too much.

He stated it would have no affect whatsover and would not damage the car.

After unplugging it, I realized the car was way more responsive and the lag had vanished.

Despite scouring the net, I cant find any evidence of it causing any damage unplugged...

Anyone have any input here?? :S

eeeerm. Nope, sorry! lol