SLK 320 noisy throttle

[starletman]

Recently my 2002 320 slk started to make an air sucking noise when you lift off the throttle i think it is to do with the butterfly but before i remove the inlet manifold,can anyone suggest other things i can try,the noise stops as soon as you touch the throttle again,i have removed the egr valve and cleaned and all the pipes around the throttle body are good,i believe this is mechanical as no fault codes have shown up.

 

[lynall]

Cant see it being the inlet flaps as all they do is alter the length of the inlet tracts and they are self contained inside the inlet manifold.

If you mean throttle butterfly its housing is held on with 4 bolts and is easy to remove, dont unplug it though as it takes a few miles to relearn the throttle settings.

From google for the 113 v8 but same principle,
At higher speeds, the flaps open, allowing intake air to take a shorter, more direct route to the cylinders for maximum high-speed power and efficiency. The electronic engine control unit determines precisely when the flaps are open and closed. The E55 uses a specific electronic control unit (ECU) to manage the increased-displacement V8, and fuel injectors have been matched to the increased airflow.




Lynall