01 540i 6-speed POSSIBLE BAD DUAL MASS FLYWHEEL? What IS IT?

[Aftermarke7]

Hello all.

I have owned my second 540i for well over a year now and I have recently noticed something strange. :help

When accelerating "spiritedly" I notice what feels like a "slingshot" of the power band. I can see it on the tachometer as well. The rpm's will rise form say 3-5k then go back down to 3k and rise accordingly. When this happens you can tell the car is holding back the power what feels like something "catches".

In other words, When I step on the gas, I hear the engine working, see the tach rise, and there is about a full second pause before the FULL power is delivered to the wheels. Further more, when the full power is delivered it does not come come smooth one bit.... it lurches forward with the full power, hence the "slingshot" description above. Feels like a turbo kicking in. :eyecrazy

I have tested the clutch by having the e-brake pulled up and releasing the clutch SLOWLY in 4th,5th, & 6th gear and it stalls normally. Also, I have never had it pop out of gear.

NOTE: When I cold start I have the vanos rattle almost every time so its definitely time to replace the seals, could this be caused form worn out vanos?

I can only imagine it is either:
+ Worn Dual mass flywheel
+ Worn Vanos
+ Worn Clutch delay valve
+ Worn Clutch

If anyone reading has any insight here or have experienced the same symptoms please reply!!!
I can run tests if there is anything that can weed out some of these probable causes. Just recommend em!

Thank you in advance!

-Mike

[JimLev]

The rpm's will rise from say 3-5k then go back down to 3k and rise accordingly.

In other words, When I step on the gas, I hear the engine working, see the tach rise, and there is about a full second pause before the FULL power is delivered to the wheels.


Classic example of the clutch slipping.
How many miles in it?

[Aftermarke7]

Hey Jim,

That's what I was thinking as well, even thought the clutch seemed fine during the "e brake test"

168k. No clue when the clutch was last changed. Looks like I'm switching to a single mass /cdv delete while I'm in there.

[edjack]

Remove the CDV and report back.

[philly98540]

E brake test is garbage. Floor it in 4th and watch tach.

[Aftermarke7]

It does it in every gear minus 1st. The e-brake test is better suited to when the clutch is more worn. The tach rise I'm experiencing seems to be early signs of clutch wear.

[BimmerBreaker]

E brake test is garbage. Floor it in 4th and watch tach.

This

Your e-brake test succesfully told you that your e-brake is working and really nothing else. From a low speed gun it in a higher gear and watch that sweet sweet clutch slip

[geargrinder]

This

This this.

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Classic example of the clutch slipping.

Also this this.