Well, my wife's '07 S dropped a cylinder a little while ago and after investigation it was low on compression on cylinder 3. I popped the intake off and took a look at the intake valves and other than being extremely carboned up, they were fine. So, that left either the exhaust or piston itself. I popped the head off and found an exhaust valve with a chunk missing (see pic). There's no damage evident to the cylinder or head (luckily) so the chunk must have gone out the exhaust. I'm sending the head for rebuild tomorrow or Weds. Obviously, I couldn't just lock the engine and cams as the cams have to come off for the head work so I need to know how to set the cam timing when it comes back. I've done cam timing before, but not on a Vanos engine. What tools are necessary and what's the procedure?

 

Yup that's an N14 engine. Nice and black combustion chambers!

From what I remember the BMW special toolset was about $300. Yea, it sucks but you need to use it to do it right. Way Motor Works sells the tool. I would forward you the service manual instructions but am away from my home office where I keep the documentation. I'm sure others could chime in here and provide the procedure.

 

I'm thinking I'll rent this set when I'm ready to time the cams rather than buy it as I doubt I'll be doing it again. The car has 130k miles and hopefully will make it to 200k before having to tear into it again, and if it doesn't it'll probably get parted anyway.

http://www.specialtyautotoolrentals.com/product_info.php?products_id=171

 

I had the same exact thing happen to me!
If you rent that tool kit for a couple days you'll be good...
Instead of top dead center you lock the crankshaft at 90 degrees as they call it..
so manually turn the crank, insert locking pin and check that all pistons are same height/level by measuring through each spark plug hole with a straw..
The camshafts will be reinstalled with the text on the center of the camshaft facing upward and lock them in place.

 

I ended up buying a tool as the rental was out and I didn't want to wait another week to put the car together. I have it 80% assembled, just the exhaust left to hook up tonight and then I'll start it up and check for any leaks/issues before taking the front out of service mode.

It wasn't a particularly difficult job, just time consuming as there is so much stuff to unhook and remove and then put all back together. All told it cost me around $900, of which I can hopefully recoup around $100 by re-selling the tool on ebay. The engine had little to no wear, I could still see the cross hatch on the cylinders which was fairly impressive considering it has 133k miles. Hopefully I don't have to pull it apart again for a while.

 

That's not too bad... did you only replace the valves that were broken? I was trying to decide whether to replace all or not.. I have about 150k miles on mine, the other valves look fine though

 

I left it up to the machine shop and they said the rest of the valves looked fine. So, they did a valve job and re-installed the valves/springs with new seals.