Anyone familiar with VANOS? I have a fault code I can't get rid of...

dang

dang

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2003 325i that I replaced the head on. Everything is dead on for camshaft timing, sensors have been replaced, o-rings replaced in VANOS units and I'm still getting a "28BC Camshaft Position Sensor Input; Mechanical" fault code. I'm running out of ideas. Got any? It sounds like it has something to do with the camshaft timing, but I've had the assembly apart and rechecked it several times with the BMW special tools. :confused:
 
Dan,

Hate to admit it but try Bimmerfest, they have a knowlegeable e39/e46 cadre that knows the M52 motor. HTH.
 
Exhaust Cam CPS

Dbl check sprocket alignment/ mounting.

Some swear only OEM on CPS.... might check. At least swap it.

If you can find the wiring diagram- check the fuse that feed the CPS for full 12v.

Dealer will want to swap the Vanos.

Wish I could help more....
 
I've done a LOT of searching on the internet and other forums and have come up with very little to go on. One other guy had the exact same symptoms in a post about a year and a half ago but didn't post a followup saying what the cause was. I sent him a message but probably won't hear back.

The sensors that I replaced were from another low-mile engine. Used OEM, but I figure the chances of putting on another bad one from an engine that was running when taken out of the car is pretty slim. I do have access to another VANOS assembly, which is probably the direction I'm leaning since I'm running out of things to try. Hell, I can swap a VANOS unit in about 45 minutes now! ;-)

The wiring is an interesting thought. I did read somewhere about that being an issue sometimes. Not sure how to proceed with that one but its on my list now.
 
I thought I'd follow up to my VANOS post after figuring out what the problem was...

The code pointed to a mechanical problem on a camshaft "position input; mechanical". After chasing the problem for two months in my "spare" time, I took it to a shop where they discovered two of the camshaft journal caps were reversed. When they went to swap them, they found that they were torqued differently, which prompted them to check the rest of the caps on both cams. ALL of the caps were incorrectly torqued! After swapping the two caps and retorquing the rest the code went away. I had a nice talk with the machine shop that did the head work, and to their credit, they owned up to their mistake and said they'd help me out if I needed to replace anything that was damaged. Engine runs great and everything "looks" okay, so it just cost me a little money and a lot of time. I'm not very happy it happened, but I'm very happy that its solved and I can move on from that car.

A stupid mistake that I should've caught myself. :mad:
 
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