M54 Camshaft & VANOS Timing
The timing assembly is complex and looks intimidating. But it all goes together smoothly once you see the install order. It's nearly impossible to put something on backwards or upside down. What had me perplexed was after assembly and a test rotation the cams were off by a few degrees. The cam lock blocks were not even close to flush on the cylinder head. And no matter what I adjusted it would always be off.
I was a little disappointed with the DIY posts and videos already out there for an M54 timing job so I made this gallery. None of them seemed to have the same problem I was having. If there was something similar it was a forum post with the usual forum nonsense. After a lot of late-night reading and even more disassembly & reassembly I was able to figure out the source of the problem. TL;DR - the VANOS tool kit had a defective assembly jig which put the exhaust sprocket in the wrong position. Others made vague references to it online so I'm not the only one.
Hopefully with this page, combined with the other resources already on the web, you get a clearer understanding of how to get this right the first time. You should have the full timing tool set to do this correctly, even if a piece of it was the source of my trouble. Other than that one piece being wrong it did make the install smoother and easier. And they’re cheap enough from Amazon and eBay.
I took these pics in my garage. Try to ignore the background clutter. I’m just a regular guy, not working out of a production studio.
Disclaimer: these are not step-by-step instructions and this is not a DIY guide. I'm only documenting my experience in an effort to save you the same frustration.
TDC
I set TDC by aligning the mark on the timing cover with a tiny imperceptible mark on the crank pulley. This pulley is so old and rusty the mark is barely visible. It will be replaced.
I confirmed cylinder 1 is at TDC by gently inserting a long extension into the cylinder, rotating the crankshaft, and watching the extension rise and fall. The marks lined up when the extension was at its highest point.
Cam Position
Cams locked in the correct position.
Timing Chain & Sprocket
The main timing chain can now be slid over the sprocket on the exhaust cam.
Note the arrow on the sprocket points to the edge of the cylinder head.
Chain Guide & Tensioner
Plastic timing chain guide and the upper tensioner installed. Access to these bolts is almost impossible once the upper chain goes on.
Note the gap at the top of each camshaft spline. This is the keyway for the VANOS piston cups to slide on.
Note the arrow on the sprocket is misaligned in this photo. I was tweaking the position for something. It must be pointing flush with the cylinder head surface.
The Struggle
The stone in my shoe on this project. No matter what adjustment or tweak I made I could not get the rear cam blocks to sit flush after rotating the engine. I always ended up with a major gap. BMW says there is a tolerance of 1mm but I was always way beyond that. The above photo was the closest I got until I found the reason....
BMWM52tuM54double VANOSVANOScamshafttiminglockingblocksnot flushcylinderheadsurfacedefect
Wrong Setup
The exhaust and intake sprockets set on the jig. This is the way the jig comes out of the box. And it’s wrong. It took me several days and lots of reading online to realize this. See next photos for more detail.
Wrong Setup
Fresh mounting after the jig. If you zoom in on the upper and lower helix you will see they are not quite aligned. The inner helix stays fixed (by the rear cam blocks). The outer helix needs to rotate clockwise a few teeth for the piston cup to be inserted. See next photo.
Wrong Setup
Top: how it is off the jig. It’s clocked wrong.
Bottom: the correct clocking of the inner and outer helix.
Wrong Setup
After you make the little turn on the intake helix your exhaust sprocket looks like this. This is wrong. The sprocket should be hard against the studs. But it’s been rotated clockwise, limiting its travel.
Right Setup
This is how the helix and sprockets look when everything is installed correctly. The helix line up correctly for the piston cups. Note the sprocket position to the studs. This allows for maximum travel when VANOS is working. The jig simply doesn't allow this position.
The exhaust sprocket has to move a tiny bit for the 3 Torx screws to install. But it's just a small amount to allow access to the holes.
Right Setup
Correct alignment with the piston cups inserted and pushed all the way in. This moves everything and you can see the sprockets have completely moved to the opposite end of their travel. Using the jig as-is the travel was cut in half and cam rotation was limited.
Before mounting the front alignment tool I installed the rest of the pieces, then loosened the screws and nuts, and pulled the cups out.
Final Assembly
Exhaust Torx screws are in. Ignore the position of the cam gears. I was checking movement when I took the pic.
On the intake side the spring washer is installed with the three nuts left loose.
Final Assembly
Spacer installed on exhaust side.
Final Assembly
Spring washer installed on exhaust side.
Final Assembly
Cam position wheel installed on exhaust side. Note the arrow aligned with the cylinder head surface.
This is the VANOS & camshaft timing kit available from Amazon or eBay.
