[Nick325xiT 5spd]

I've been obsessing about the CDV lately. I'm going to have to get my car up off the ground sometime and go exploring with my camera.

 

[Nick325xiT 5spd]

I know that one person with a 330xi has at least claimed that he had a CDV removed from his car, one very much like the 5series types.

 

[Cowboy]

Ok, I'll bite. What's a CDV?

Let me guess.. Central Drive Valve! No, wait.. hmmn.. Carbon Dating Ventricle! No, that's not it.. how about a Clutch Doo-whack Vestibule!

Hmmn..

 

[JST]

Ok, I'll bite. What's a CDV?

Let me guess.. Central Drive Valve! No, wait.. hmmn.. Carbon Dating Ventricle! No, that's not it.. how about a Clutch Doo-whack Vestibule!

Hmmn..

"Clutch Delay Valve." It's essentially a restrictor plate on the hydraulic line leading to the clutch. It's designed to minimize driveline shock by limiting the speed at which the clutch can be engaged. Some argue that it is the reason that certain E39s are hard to drive smoothly.

If the Xi has one, it might make sense. Presumably, the weak link in the i and Ci is traction; IOW, dropping the clutch causes the tires to spin. With the Xi, that won't happen, so perhaps the idea is to limit the amount of shock that can be sent through the driveline.

 

[blackdawg]

nick-o: do you think the culprit is more likely the dual mass flywheel?

the dual mass flywheel has that lousy mushy feeling upon engagement.

 

[The HACK]

Re: nick-o: do you think the culprit is more likely the dual mass flywheel?

the dual mass flywheel has that lousy mushy feeling upon engagement.

I don't know about Xi's...But I know on i, Ci, and iT's the reason is due to the self-adjusting clutch mechanism...there's a spring loaded mechanism that pushes the clutch plate to a certain position as it wears, and that spring mechanism is also buffering the clutch engagement. I've been under my car exploring the clutch hydraulics system and CDV doesn't exist as a seperate valve on the later production E46es.

Some have speculated that the CDV is now integrated into the clutch slave cylinder.

 

[pps-325xit]

According to Bentley manual, xi's have same make of transmission as the 330i's, but it's a different model.

 

[ERK]

According to Bentley manual, xi's have same make of transmission as the 330i's, but it's a different model.

I think the xi's have different gearing. On the bmwusa site they list the gear ratios as the same for the i and xi but the final drive ratio is different. :dunno:

 

[Nick325xiT 5spd]

final drive ratio has nothing to do with the tranny, though.