Cam Bolts and Valve Timing

[O-cha]

Originally Posted by beta

Is there enough clearance if you use the actuator? That does make sense. The reason we needed extra clearance was to remove the vanos caps, so we can actuate it by hand, rather than using the 300$ actuator.

I also don't have an air compressor, but there's a DIY mechanic shop around me that has all the tools.

It's still really tight but it is doable. The procedure also varies slightly from the e46 since in order to start bolting it on it has to be half out/in vs all way way out.

Actuator was more like $150. I've had to replace it once because it had a circuit board go bad.

[beta]

Originally Posted by O-cha

It's still really tight but it is doable. The procedure also varies slightly from the e46 since in order to start bolting it on it has to be half out/in vs all way way out.

Actuator was more like $150. I've had to replace it once because it had a circuit board go bad.

Interesting, thanks for the info. I thought the actuator was 150, but you needed the fitting ($30) and the cable adapter ($150).

[O-cha]

Originally Posted by beta

Interesting, thanks for the info. I thought the actuator was 150, but you needed the fitting ($30) and the cable adapter ($150).

There's a cable, but all it is is a standard connector that goes to ground and +12v, so I just bought a pigtail of that connector. I don't have the PN though unfortunately.

[StickMon]

I built the actuator electrical portion for under $40. Not because I had to, but because I was cheesed off that they charge so much for it.

I also took one of the caps off with the Vanos installed. Comes right off, and there's plenty of room to get the cap out.

I'm still not convinced that either of these helps get the Vanos out without tilting the engine or starting at the license plate and disassembling your way to the engine. That's why I'm waiting for someone else to try it first.

[O-cha]

Originally Posted by StickMon

I'm still not convinced that either of these helps get the Vanos out without tilting the engine or starting at the license plate and disassembling your way to the engine. That's why I'm waiting for someone else to try it first.

I have done it many times, the actuator makes it possible.

[mike519]

Originally Posted by beta

Just in case, the visible bolts are not the ones that loosen up, did you look from the back?

Yeah, looked from the back...could only see four for now...once I start the adjustment and turn the cams I will be able to see the others. So far they look OK.

[beta]

Originally Posted by O-cha

I have done it many times, the actuator makes it possible.

Could you go into it in some detail? I didn't really see enough clearance to even get the longer bolts on there to slide the vanos back.

All detail you can provide would be greatly appreciated!

[StickMon]

I started reading Beisan's how-to just to pass some time.
Here's a bit of trivia that I found interesting.
You need to fully retard both camshafts to get at the connections to the Vanos pistons. (We knew that).
I tried to turn my camshaft with the solenoid block removed, and even with the cap removed, and I couldn't budge it.
I wasn't willing to force the issue. I was afraid I'd bend the spindly connection between the spline and the piston.
Beisan says:
"If camshaft resistant to rotation rock camshaft back and forth to release seize."
That sounded vaguely familiar, so I checked the BMW TIS and it corresponds to:
"Alternately press toggle switch buttons 1 and 2 several times on special tool 12 6 050".
That step never made sense to me. Now it does.

So I guess I should have wiggled it more. I'll try that next time I'm in there.

[O-cha]

Originally Posted by beta

Could you go into it in some detail? I didn't really see enough clearance to even get the longer bolts on there to slide the vanos back.

All detail you can provide would be greatly appreciated!

I don't know what bolts you're talking about, none of the ones you're supposed to remove can't be removed simply.

Originally Posted by StickMon

I started reading Beisan's how-to just to pass some time.
Here's a bit of trivia that I found interesting.
You need to fully retard both camshafts to get at the connections to the Vanos pistons. (We knew that).
I tried to turn my camshaft with the solenoid block removed, and even with the cap removed, and I couldn't budge it.
I wasn't willing to force the issue. I was afraid I'd bend the spindly connection between the spline and the piston.
Beisan says:
"If camshaft resistant to rotation rock camshaft back and forth to release seize."
That sounded vaguely familiar, so I checked the BMW TIS and it corresponds to:
"Alternately press toggle switch buttons 1 and 2 several times on special tool 12 6 050".
That step never made sense to me. Now it does.

So I guess I should have wiggled it more. I'll try that next time I'm in there.

You're just budging the cam. You wont bend the small connection, all that is responsible for is an in and out motion, it rotates 100% freely. Toggling 1 and 3 corresponds to pulling in the pistons. You don't have to have the cams fully retarded, just in a position where the shaft is accessible. Fully retarded will make it the most accessible though as well as make the vanos unit most easily removable on our cars.


Let me make this very, very clear for the millionth time. The ONLY thing you can dissemble without re-timing the motor is the vanos unit itself. If you take the axial pistons out you lose the timing of the motor. They will pop right out if you go moving the camshafts after taking off the vanos, and you cannot get to the bolts everyone wants to check/replace without doing so. This also applies to the bolts that hold the actual cam sprocket on. The bolts everyone wants to replace are not the sprocket bolts, but the camshaft bolts, you cannot get to these without removing all the sprocket bolts and the axial pistons. The only thing that keeps the cam in time with the sprocket/crank is the axial piston which bridges load between the cam and sprocket.

[beta]

Originally Posted by O-cha

Fully retarded will make it the most accessible though as well as make the vanos unit most easily removable on our cars.

So even with our very limited space in front of the vanos, your'e saying it's enough clearance to remove/replace the vanos.

Can you think of any caveats/gotchas/special tools or anything that you had to adjust to follow the TIS?

[yousefnjr]

Originally Posted by O-cha

Fully retarded will make it the most accessible though

Eh hehe.. He said "fully retarded," Beavis.. Eh hehe

[O-cha]

Originally Posted by beta

So even with our very limited space in front of the vanos, your'e saying it's enough clearance to remove/replace the vanos.

Can you think of any caveats/gotchas/special tools or anything that you had to adjust to follow the TIS?

There is a special note on the newer TIS for Z4s. You need the actuator, timing tools and the spacers, you could cheat the spacers I guess with something else though.

You will not be able to torque down the cam sprocket bolts without a straight torque wrench but that goes for the e46 as well.

[beta]

Originally Posted by O-cha

There is a special note on the newer TIS for Z4s. You need the actuator, timing tools and the spacers, you could cheat the spacers I guess with something else though.

You will not be able to torque down the cam sprocket bolts without a straight torque wrench but that goes for the e46 as well.

I have all the tools you mention (including torque wrench) except what do you mean by spacers? The shim kit or something else?

Does the note for Z4s say anything important? The TIS I have is the last one you could download which is december 2007. If it's important enough I guess I could pay the $30 single day access and print out a pdf.

[StickMon]

Spacers.

I just bought them from Tischer along with the air noozle.

The idea is to "pretension" the hubs so they're not too floppy, but have less friction against the sprockets than the camshafts have in the journals.
Then you set the Vanos piston positions with the actuator, and jam the Vanos home against the spacers.
As you do, the hubs turn CCW as the splines are driven into them, and the camshafts don't turn. When it rests against the spacers, the splines are inserted to the correct depth.

Others have found, with some success, that the exhaust spline should end up just sub flush and the intake spline should be sticking out "just a little". So you could just set them thus and skip the whole business. This would allow you to torque the hub bolts without a crow's foot, since you could do it with the Vanos off.

Frankly, I wish BMW would have simply defined "just sub flush" and "sticking out a little" in mm. Then you could just set it up with a depth mic and be done with it.

I'm going to get a depth mic and measure mine when I eventually remove the Vanos, before disturbing the timing. I know from INPA that my intake is within a degree, and my exhaust will be after I tweak it a little.

[StickMon]

Reading the TIS for the 100th time, here's where the splines get properly set.
In an earlier post I described it as "something magic happens" because it's a little less than obvious.

"Press buttons 1 and 3 on special tool 12 6 050
simultaneously. The solenoid valves are activated and the air can
escape from the hydraulic pistons of the VANOS adjustment unit.
Simultaneously push on VANOS adjustment unit until it rests on
special tool 11 9 170"

Buttons 1 and 3 are fully retarded (retracted).
11 9 170 are the spacers.
At this point the hubs are free to rotate relative to the sprockets, and the camshafts remain fixed in the reference position. With the Vanos pistons fully retracted and the Vanos body resting on the spacers, the splines will be inserted into the hubs to the correct depth.

One of these days I'll measure "the correct depth" with a mic, which opens up more options on how to get there.

[beta]

Very good info thanks StickMon, looks like i'll have to order even more parts to get this done.

My concern about the bolts was the two M6x60 bolts you temporarily install to align the vanos. The space is so limited i wasn't sure they could go in.

[O-cha]

Timing is finally set when you tighten the 6 (I think) hex bolts on the sprocket. Prior to that the sprocket is not locked to the helical gear, and as such not locked to the cam.

It's important to mention that even after those spacers are used, and 2 of these bolts are tightened, timing STILL is not set, that only provides the pretenison. Immediately following this when the vanos is tight and those sprocket bolts are tightened is when the timing is set.

I like to take that opportunity to check and make sure the camshafts are still in the correct location (easy for them not to be if you do anything wrong) before continuing. The pistons MUST still be in there fully retarded position as well. You can confirm that by pressing 1 and 3 while rotating the cam in opposite direction. (compressed air supply does not have enough power to actually rotate the cam, you have to do it manually or it wont budge)