Thread: Exhaust leak?
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Old 10-22-2012, 06:44 PM
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Mein Auto: 2004 330Ci ZHP 3 pedals
Originally Posted by QAfred View Post
FB, still curious on the answer to your question. Could you enlighten us?
What could both scenarios be?

More pronounced as revs are rising = ?

More pronounced as revs are on downrev/decreasing = ?

reason I ask is that OP has one issue (rising RPM rattle / noise) I have the other (vibration on downrev at 2000 to 1800).
Cleaning ICV (and MAF/DISA while they were out) cured most of my vibration on the downrev...70%.
From my personal observations, VANOS rattle typically occurs between 1800 and 3000....while still present, it seems to be a little less pronounced when under load (i.e., "on the uprev"). The "marbles in a coffee can" noise seems more pronounced as the revs descend below 3 grand, with less load on the engine.
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