06 Z4M R Vanos Cam Bolts

[onebluemcm]

Hey, O-cha

On the Z4, you said it would be a harder job because of clearance, can it be done though with out lifting the motor? My hunch is yes - if so, what is the critical step, if there is one, to doing it within the confined space?

[O-cha]

Originally Posted by onebluemcm

Hey, O-cha

On the Z4, you said it would be a harder job because of clearance, can it be done though with out lifting the motor? My hunch is yes - if so, what is the critical step, if there is one, to doing it within the confined space?

According to BMW yes it can be done. Normally you unbolt it, extend the pistons, and then you have access to the threaded shafts nuts. In the Mcoupe it looks like you do the same thing But will have to move the cam to extend the actual vanos gear in and out until you have access to the threaded shafts nuts.


It is VERY close though and I'm not sure if it can actually be done when I took a second look.

It boils down to with the vanos unit out as far as it can go, will you have access to the nuts of the threaded shaft and be able to move the cam to the right position (they don't move very freely)

[onebluemcm]

Originally Posted by O-cha

According to BMW yes it can be done. Normally you unbolt it, extend the pistons, and then you have access to the threaded shafts nuts. In the Mcoupe it looks like you do the same thing But will have to move the cam to extend the actual vanos gear in and out until you have access to the threaded shafts nuts.


It is VERY close though and I'm not sure if it can actually be done when I took a second look.

It boils down to with the vanos unit out as far as it can go, will you have access to the nuts of the threaded shaft and be able to move the cam to the right position (they don't move very freely)

Ok, I understand the theory. Just two other things - the cam can be rotated with a wrench? I've seen pics I think of a wrench on the cam shaft - it must have a designated place for a wrench?

And then what is it that makes rotating the cams difficult - just the tension or friction present with the thing still as compared to when it's running? That must be why the VANOS unit has such high pressures in it...

As much as I'd like to try something like this on my own, I'm still being realistic and am not sure I'd get it dead on correct. I'm up for a challenge, and I'm always trying to learn new things mechanically to increase my skill and this sort of job is about where I am with technically challenging work. I think I fully understand the issues and what special tools are needed (or unnecessary) and I'm pretty meticulous about things. But still, uncertain.....

[O-cha]

Originally Posted by onebluemcm

Ok, I understand the theory. Just two other things - the cam can be rotated with a wrench? I've seen pics I think of a wrench on the cam shaft - it must have a designated place for a wrench?

And then what is it that makes rotating the cams difficult - just the tension or friction present with the thing still as compared to when it's running? That must be why the VANOS unit has such high pressures in it...

As much as I'd like to try something like this on my own, I'm still being realistic and am not sure I'd get it dead on correct. I'm up for a challenge, and I'm always trying to learn new things mechanically to increase my skill and this sort of job is about where I am with technically challenging work. I think I fully understand the issues and what special tools are needed (or unnecessary) and I'm pretty meticulous about things. But still, uncertain.....

Yes there's a hex on the camshaft, it's difficult to rotate for various reasons, a lot of tension for one. When the engines rotating it's not so difficult.

The tools you would need are like $800 FYI.

[runnerx]

I concur with what O-cha said. Z4M has a crossbar in front of the engine which makes VANOS removal impossible without the expensive special tools. You'd need BMW special tools to get the VANOS "pistons" to retract for removal and extend for installation. I spent $900 on those tools because I track my car and want to be able to check my exhaust hub and cam bolts when I do valve adjustment.

[donoman]

Originally Posted by Ron Stygar

http://www.bimmerfest.com/forums/showthread.php?t=23433

Z4 M Coupe: LL93033 May 2006

6 157 3 765
32 6 S4

Does this mean that cars built after this car (5UMDU934X6LL93033 Prod Date: 4/27/2006) all have the updated bolts?