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Old 11-08-2012, 08:46 PM
Supercourse Supercourse is offline
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Mein Auto: 2004 X3 2.5i
Originally Posted by chewchewone View Post
when I remove my oil cap, the engine shakes, is this normal?
Revs are going down because you have introduced a vacuum leak in what is essentially a sealed system.

Air from the removed filler cap will be drawn into the the intake without being metered by the MAF.
(In other engines that use a MAP instead of a MAF, the MAP compensates and the idle speed will be stable or even increase when the oil filler cap is removed.)

In most cases I wouldn't expect the idle to go down enough that the engine shakes and wants to stall.

Might be indicative that a slightly rough idle already exists because of some issue.

Not sure if all M54 and N52 engines should have the same idle speed, whether Auto or Manual?
Mine seems consistent at 800.
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