Roundel's Mike Miller (TechTalk) on the E39 M5 and Clutch Delay Valve - The Unofficial BMW M5 Messageboard (m5board.com)

E39 ///M Power · 17th December 2007, 04:55

Tech Talk in this month's Roundel (Dec. '07) has a response dealing with a few questions on the E39 M5 ("Politically Incorrect? Not Mikey!"). Mike Miller, the author of Tech Talk, suggests the reader might want to remove his clutch delay valve.

I always thought the E39 M5 didn't have the CDV, so I e-mailed him about it. Here's his response:

Quote:

My experience with the CDV is, you never really know which car has one and which car doesn't unless you actually get under there and look for the part. This is not confined to the M5, either.

Also, I didn't really recommend removing it. I believe I told the guy some people prefer the clutch action without it. Personally, I wouldn't remove it, but it doesn't bother me nearly as much as it bothers some folks.

I've seen the underside of precisely three E39 M5s, one had a CDV; the other two did not. They're pretty rare around here. (The one with a CDV was a press car, but they are usually just regular production cars -- nothing special for the writers.)

So, with respect to the M5, I don't know how probative my experience can be on the CDV issue, with only three cars under my belt.

Can anybody shed light on this? Has anyone else seen a CDV on their M5? Has anyone looked?

CSBM5 · 17th December 2007, 05:02

Quote:

Originally Posted by E39 ///M Power

Tech Talk in this month's Roundel (Dec. '07) has a response dealing with a few questions on the E39 M5 ("Politically Incorrect? Not Mikey!"). Mike Miller, the author of Tech Talk, suggests the reader might want to remove his clutch delay valve.

I always thought the E39 M5 didn't have the CDV, so I e-mailed him about it. Here's his response:

[/i]

Can anybody shed light on this? Has anyone else seen a CDV on their M5? Has anyone looked?

He's once again wrong. No M5 ever had a CDV. I recently e-mailed him about his reply two months back to a guy asking about running OE rear wheels all around on a 330i ZHP. He told him the big tires/wheels would rub like crazy and not fit up front -- I e-mailed him that I've run that setup on my ZHP now for over a year with absolutely no rubbing at all...plenty of strut clearance, PLENTY of fender clearance. Sigh...

E55AMG2 · 17th December 2007, 06:30

He doesnt know specifics, just general automotive stuff. No E39 M5 ever had a CDV, ever.

Beemer Guy · 17th December 2007, 18:36

Mike is very biased (ask him about an automatic transmission in an E36

)but he's also quite knowledgable and provides a good service to the club. Unfortunately, on the E39 M5 question, he rather screwed the pooch, including his response about driving it on track.

I also think he gets a little too anal on the oil requirements for the S62, but that's another thread...

On the other hand, it's tough writing anything for any enthusiast publication, as you just know he gets blasted on probably every issue about something! So let's not beat up on him too badly, OK?

Collectively here we know more about these cars than any one person possibly could.

Michael

crnjyM5 · 17th December 2007, 19:02

Strange, I've always felt that someone at the plant in Germany had one too many drinks and installed a CDV in mine. It has been 4 years coming to 5 now that I have been driving her on an almost daily basis. To this day, I still really can't determine where the clutch engagement point is. Some days, she drives like a dream-- I shift like a champ. Other days, its like I am learning how to drive stick all over again. First and second gear is extremely horrible and the car makes all kinds of strange noises as I try my damn best to let the clutch in smoothly. It is particularly embarrassing should you have a full car of people and the clutch decides its just not going to engage without giving you crap for it.

Maybe its time I took her in to have people take a look at it.

E55AMG2 · 17th December 2007, 19:13

Yes, and you shouldnt drive by just knowing where the clutch engagement is...you should be doing it by feel.

gsfent · 17th December 2007, 20:04

Quote:

Originally Posted by Beemer Guy

Mike is very biased (ask him about an automatic transmission in an E36

)but he's also quite knowledgable and provides a good service to the club. Unfortunately, on the E39 M5 question, he rather screwed the pooch, including his response about driving it on track.

I also think he gets a little too anal on the oil requirements for the S62, but that's another thread...

On the other hand, it's tough writing anything for any enthusiast publication, as you just know he gets blasted on probably every issue about something! So let's not beat up on him too badly, OK?

Collectively here we know more about these cars than any one person possibly could.

Michael

I don't think folks would have a problem if he published the correct answer in a future edtion of Roundel so people haven't been misled. Giving credit to the person who had the right info would be nice, but not required.
Regards,
Jerry

CSBM5 · 17th December 2007, 20:06

It's the stupid self-adjusting pressure plate most likely that you are feeling. It is a pathetic design and is sometimes responsible for burned clutches as it gets hung up and won't allow the clutch to fully engage. The only M5 experience w/o such I've had was driving UUC Rob's M5, briefly, a few years ago with the 850 clutch/large flywheel in it, and the engagement on that was really sweet -- vastly better than the stock clutch. Of course it did have the transmission clatter at idle due to the single mass flywheel.

CSBM5 · 17th December 2007, 20:07

Quote:

Originally Posted by gsfent

I don't think folks would have a problem if he published the correct answer in a future edtion of Roundel so people haven't been misled. Giving credit to the person who had the right info would be nice, but not required.
Regards,
Jerry

Excatly. His answer about the ZHP rear wheels up front thing stands uncorrected, and it is completely false. I had assumed a followup correction would be published after my note to him, but so far I've not seen anything.

emccallum · 17th December 2007, 21:57

I have mixed feelings about his column...I really enjoy reading it, as I enjoy wrenching on BMW's. I have emailed him twice. Both times I got a prompt reply. First time was about replacing a leaking air suspension part. Since he had never worked on one, he said take it to the dealer. fixed it myself. Emailed him vack to tell him how I found the leak and how I repaired it. No reply. Second time was to ask if a dual mass flywheel could fail so bad that it would mimick a slipping clutch.....you would have thought I asked Hillary about supporting the war in Iraq....as I got a reply about wether I was using a SAchs clutch and replaced the fork spring.?? So, I conclude, if you ask a question he knows the answer to, he is very good. If not, then back to the net! By the way, anyone had a dual mass fail and slip with the clutch still in good condition?