Quote:
|
Originally Posted by weirluo
discovered some air intake whistling when I push the pedal (not too hard, around 2000rpm), it's x5 MY05 3.0D sport with almost 70000km on the clock, any opinions why it whistles? and the engine shakes when idle? is this typical diesel engine behavior or just something has got wrong?
|
Hi,
Hard to say remotely like this, when one do not see the car physically but there is a quick and maybe useful guide here:
This whistling can have several causes.
- One can be incorrectly sealed intake tubing a) sucking in the air between air filter and turbocharger, b) blowing out the presurized air between turbocharger and cylinder head.
- Another can be slightly bent turbochargerīs intake turbine flaps a) after unfiltered air with any contaminant entered into the turbocharger b) after taking improper care of turbocharger (immediately reving engine high when cold, stalling engine and not allowing it to cool down after high load or fast driving, etc) causing too big free play in TC axle sleeves and allowing then flaps to touch TC housing. Bent flaps rotating over 100 thousands RPMs create dull whistle.
The engine should not shake much when idling. If You put a glass with water on it it should not move or spill at all but You will see a small waves on water surface of course. Find the root cause of the imbalance, first check if the engine runs smooth (all cylinders operates) and check the engine (and the gearbox as well) rubber mounting (see
http://www.realoem.com/bmw/showparts...76&hg=22&fg=05 #8). I had all of them damaged and it caused not big but quite uncomfortable vibrations during a drive and it shaked with a car heavily when I turn the engine off. Check vacuum hoses and electr. valve too (#11-17).
Good idea as well is to find a skilled friend that can help You locate and fix the problem. This "something is whistling there" remote fault finding can sometimes be totaly incorrect.
Cheers, Kamil