e90 CDV delete - worth it?

[kuiper]

Spent a while looking for a decent manual e90 330i. Now have the perfect car and I adore it. Only let down is first to second changes - I’ve only ever driven manual cars and never had an issue until now. Wife finds it hilarious.

Is the CDV delete worth doing and does it really help?

[stevesingo]

I was a skeptic, but whilst doing some other work on the car, I removed the CDV and I was surprised at the difference.

It's not difficult to do so try it.

[mikeyscott]

Keep thinking about this on my 135i as the manual tbh is rubbish

[cerb4.5lee]

I hated the first to second gearchanges in my Z4M and you had to just baby it which completely spoilt the fun. The manual gearbox on my E92 M3 was slightly better but it still didn't like to be rushed.

Bmw's manual gearboxes suck, and it's no surprise to me that the majority don't bother with them...and choose the Auto/DCT instead.

[stevesingo]

I am maybe beginning to think you just can't use them properly.

I've had four, and all were fine enough. On a scale of best to worst, they definitely don't sit in the bottom third, probably upper nid third.

[cerb4.5lee]

No other manual car has suffered from the problem I had with my Bmw's. In the Ford's/TVR/200sx I've had you could change gear from first to second as fast as you wanted. The BMW's won't let you do that, slow and steady is the only option with them.

[Mike335i]

The gs6-53bz used in the N54 engined cars and the M3 (and the manual M5 and M6 sold in the US) isn't the best box, but not the worst. The CDV delete is a popular mod but I can't find anyone willing to do it for me! None of the local specialist are interested in the job.

We have a M32 box on the Alfa and that is terrible. Unreliable, vague and long throw.

I think my favourite gearshift that I can remember was the 5 speed in the Mk5 Golf. For some reason it just felt right, short throw, precise and mechanical in feel without being notchy and neither overly heavy not light. Much nicer than the 6 speed box for some reason, as per the GTI etc. We had a 1.9 TDI with it years ago.

[sixpistons]

It’s an easy diy mod - it takes longer to jack the car up and remove the undertray than remove the CDV and rejoin the clutch hose, which takes 30 seconds. If you’re willing to get your hands dirty it’s free too. I bled the clutch after but almost no bubbles came out so don’t think it’s essential. Big improvement in clutch feel so I can thoroughly recommend it.

[Mike335i]

I would have a go myself, but I have a gravel drive and I'm not climbing underneath on that! I'll find somewhere to do it, having the gearbox and differential oil changed on Tuesday so might see if they will do it then.

[stevesingo]

With all the covers off for changing the gearbox oil, it will take about 90secs to remove the CDV. It really is that simple. You might want to ask the garage to bleed the clutch whilst they are at it. We change the brake fluid periodically, but the clutch fluid always gets forgotten.

[gizlaroc]

It takes 10 minutes.

Remove the unit and push the grommet out that restricts the oil flow, then replace it again.



It makes a hell of a difference.

However, from 2005 through to mid 2011 all manuals suffer from an really poor clutch, or rather flywheel, which is what causes the judder when pulling away, more noticeable uphill, and there is no getting around that unless you pester BMW for the revised unit.
Probably too late now to get them to do it.
It should have been a recall really, but with so many millions of cars it was only done if customers complained, and really complained.

But definitely remove the CDV, it makes a huge difference.

[SebringMan]

Definitely bin it. Like cerb said earlier the changes are crap. I had the same problem as you in my 323i. A friend's 328i with the CDV delete is alot better.

Why do you think BMW put the CDV in? Sure, it can result in smoother gearchanges but it can be annoying for keen drivers who just want to do a quick gearshift and potentially damage the syncros trying to do it.

[to3m]

Interesting thread; I've always found the gearchange in my 330i a bit disappointing. It seems to be unreasonably difficult to reliably do it smoothly - with 1st to 2nd being particularly bad - and every time I do a dodgy gearchange, the car feels a bit juddery to drive for a minute or two afterwards. Mine is a 10 plate, so perhaps this is due to the flywheel issue mentioned. But it's always possible I've just forgotten how to drive.

(I think the E46 330d I had before had a CDV, but the gear changes were a lot easier. Perhaps the CDV was less aggressive, or maybe it helps that the engine revs didn't fall as quickly - not sure.)

Not sure I'm up to the task of doing this as a DIY job but I might enquire next time my car has to go to the garage...