Hi bro, can PM me the workshop. My pre Lci E60 is having steering wheel vibration
And engine humming at 850rpm. No matter how the workshop tune the rpm down or up, it will
return to it's idle rpm of 850rpm. After months of trouble shooting I managed to find out the root cause. Here it goes, when
I tried to put an ice pack on the ambient temperature sensor located under the front bumber and
bring it down to 26 deg C or lower, and start the engine, the idle rpm is able to redued from the 850rpm
to 700 rpm and all forms of vibration and engine humming is Gone!. And as the
Ambient temp starts to increase to >28 deg C, the idle rpm raised back to 850 with the vibration and
engine humming sound. I able to repeat and observed this over and over. I even drive around
with an ice pack secured at the ambient temp sensor and the idle rpm can be maintained and
stable at 700 rpm even if I ramp the rev up. This is definately a temperature
related issue. But I need a good workshop to tell me how would the effect of ambient temperature
affect the idle rpm and causing the engine to start humming and nail down the root cause and replaced
those faulty parts