E46Fanatics - View Single Post - What are pros and cons of removing CDV
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Old 11-09-2012, 03:49 PM   #5
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Join Date: Apr 2006
Location: Montreal
Posts: 85
My Ride: '05 330i ZHP
First, the CDV: The Clutch Delay Valve is intended to slow down clutch engagement in order to minimize powertrain stress. Think of it as a damper between the clutch cylinder and clutch mechanism. It is also an engineer's approach to preventing burnouts. If you try really hard, you will burn the clutch before the tires :-)

The clutch on an E46 BMW is a complex affair:
- Dual mass flywheel. (Two separate pieces assembled with springs to control movement relative to one another.)
- Ridgid hub disk (NO SPRINGS so the simplest piece)
- Self-Adjusting Pressure Plate. (Complex spring mechanism intended to maintain consistent pedal travel regardless of wear levels)
- Hydraulic flow valve (a.k.a. CDV)

If you can't get smooth engagement in normal city driving, you may want to have your mechanic check the car. Often, this behaviour is the result of a broken flywheel.

CDV removal is simple and harmless as long as you don't abuse ...

Last edited by hamadyr; 11-09-2012 at 03:52 PM.
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