Weird Clutch Engagement - Page 3

Flybot · 7th April 2009, 20:43

Was DSP off?

bud4ya · 7th April 2009, 20:46

It was. Sorry I should have stated that. It was off both times it happened. I had sport button on also

Quote:

Originally Posted by Flybot

Was DSP off?

bud4ya · 8th April 2009, 14:56

Ok I drove teh car today and I can not make the clutch slip in any gear. I tried 3rd at 3,500 and mashed teh gas perfect pick up. I tried 5th at like 2k RPM's and slow to pick up until it hit power band then the car started to move. I did this numerous times with not a hint of slippage.

So the only thing I can think is cold tires just slipping on cold pavement. Like I mentioned before if it was slipping when I hit second and mashed the gas it would have banged right off the rev limiter quick I would think.

What I will do is test the same fast shift at high RPM from 1st to second when the roads heat up a bit and see if the tires grip then or if I get the same thing.

I would like to thank everyone for their input. So for now it sounds like the clutch with 54k on it is still good.

IRISH M5 · 8th April 2009, 15:24

Now you can put the clutch job savings into some mods

Quote:

Originally Posted by bud4ya

I would like to thank everyone for their input. So for now it sounds like the clutch with 54k on it is still good.

bud4ya · 8th April 2009, 15:30

I agree. I am looking at doing a short shifter and exhaust. I was going to research on here if there are directions for installing a short shifter and where to buy it from. I can not be that hard to do.

I had teh short shifter in my 540 and it was great

Thanks

MrCrashRR · 21st April 2009, 08:35

Hey I've been out reading up on the new car and came across this

e36 trunk handle ( have no idea why its listed as a trunk handel, but its a link to the UUC webpage)

"The cause is an added check valve (BMW calls it a "lock valve") in the clutch hydraulic circuit that is intended to slow the engagement of the clutch as you release the pedal. This constant engagement device is intended to smooth out the feel of shifts and potentially reduce the shock load on the drivetrain. The reality is it causes a high rate of wear on the clutch and excessive heat buildup in the flywheel leading to early failure.

...and also on E36 M3/MZ3 3.2l with aftermarket lightweight flywheels!

The two possible locations:
(click for a larger view)

A little-known detail about the 1996-1999 M3/MZ3 3.2l (including Euro cars) is that they too have this part. Similar to the affliction of the E46 and E39, except this valve only seems to affect cars with aftermarket lightweight flywheels. Due to the quick-revving nature of these setups, the slow-down of the check valve causes momentary excessive clutch slippage. A particular example is a "power shift" where the revs hang for a moment before fully engaging. M3s with the 3.0l engine do not have this part, nor do any other E36.

"
Seems to me like this could be the cause of it.

CSBM5 · 21st April 2009, 12:46

The E39 M5 doesn't have the clutch delay valve. Ancient subject here talked about a zillion times. For some strange reason, BMW did install one on the Z8, but the M5 was made without one.

Frye · 21st April 2009, 14:00

bud4ya, glad to hear you got everything figured out. Just make sure to keep the RPM's low when slipping the clutch, and never give it too much throttle till the clutch is fully engaged.

I think you guys forget sometimes, we drive a racecar, not a 5 series, it's not gonna have a clutch delay valve.

bud4ya · 21st April 2009, 14:54

Thanks

It has not done it since that day. So I came to the conclusion it was the cold road and tires slipping causing the RPM's to shot up. Since it has warmed up it connects up and goes. But with 54K on it I would imagine it will go anytime.

We will actually be in Orlando end of this week through the weekend at Disney with the kids. I hope the weather stays as nice as what it was last week down there.

Quote:

Originally Posted by Frye

bud4ya, glad to hear you got everything figured out. Just make sure to keep the RPM's low when slipping the clutch, and never give it too much throttle till the clutch is fully engaged.

I think you guys forget sometimes, we drive a racecar, not a 5 series, it's not gonna have a clutch delay valve.

NogginM5Beast · 21st April 2009, 16:02

I bought my car a little more than a month ago and have had this happen a couple times. The gist is that you have to wait a millisecond after you FULLY engage the clutch before mashing on the throttle. This is unlike any other manual i've driven, where you can get on the gas as you let the clutch out. The M5 has enough power to prevent the clutch from fully engaging if there's enough throttle given during the engagement process. The clutch then slips, revs shoot up but the car isnt accelerating. This is BAD. This especially manifests itself in the upper rev ranges, when going from 2->3 and 3->4. This car demands a different shifting technique than most. This is also why you see so many burnt out clutches in these cars at 40-50k.