VANOS Intake Sprocket Rotation

[Blufire]

I'm on the last leg of the journey to button my car back up after replacing the thrust washers, intake/exhaust sprockets, and the VANOS unit itself. I reinstalled the back thrust washer, studs, intake sprocket, front thrust washer, and outer washer, in that order. My car's production date was 3/94 (towards the 'later' end of the 325's production run i'd have thought) yet it had no spring plate.

Before torquing down the nuts, the sprocket assembly rotates the prescribed 20° as expected. However, after torquing the nuts down to 85 in-lb (~10 N-m), the assembly no longer rotates by hand or even using the sprocket rotating tool. I've read several guides say that this should not be the case. Even without that warning, this problem prevents the complete reinstallation of the VANOS.

After doing some research, it appears many people have this problem. Are the studs and nuts really the cause of the problem? The thrust washers and intake sprockets are brand new, which leaves the nuts to be the only remaining frictional components that aren't polished and new... are they really to blame for holding up the entire assembly? Should I update my engine with the spring plate?

[m2pc]

In my last E36 (a 1997 328is) it was very difficult to turn these sprockets, even with the spanner tool, and even with the spring plate on my car.
IIRC I used new nuts on the sprocket, soaked everything in motor oil before assembly, and it was still a very stiff setup. I kept wondering if I was doing something wrong, or if it was normal.

I ended up bolting everything back together and never got any VANOS faults or had any problems for over a year from that point until I totalled the car.

Have you tried putting some motor oil on the assembly and seeing if that helps? IIRC the VANOS system actually has an incredible amount of pressure when operational, so it may very well be that you cannot easily move it by hand, but in operation it will be fine.

Can anyone else confirm this?

[Blufire]

I covered all parts, even those that weren't apparently in friction, in oil. If it was stiff but still movable, I could have probably convinced myself that it would be fine once in operation. But I can't move it even just a little bit with the sprocket tool, which is what is required to reinstall the VANOS and sink its plunger into the intake sprocket splines, if I understand correctly. I might try getting a spring plate, studs, and bolts later today from the dealer...

[Blufire]

Well, this is strange... after letting the car sit for a few days with the nuts untorqued, i came back to it and tried again. After torquing the nuts down, the assembly rotates - by hand! Not easily, but it rotates. Good to know after I ordered $60 of parts to fix the problem...

[m2pc]

Gotta let that oil soak in for a few days! :lol

Glad to hear you're almost done. I remember the mix of excitement and nervousness (will it start?) when I did my HG a few years ago.

[Blufire]

Arghh... So I made the mistake of convincing myself I needed a spring washer, so I took the assembly apart again, got the washer, put it on, and... the intake sprocket won't rotate again. Is there an actual reason why letting it sit for a day or two would work, or is something else wrong? Why shouldn't it work the first try?

[walker7182006]

I did the vanos rebuild and only came across one problem (i had to have the ring shaved down to eliminat the movement on the sproket). i ordered my stuff from
[B]Beisan Systems (bee-saan)
2109 Longwood Drive
Raleigh, NC 27612
USA
(919) 676-1939 begin_of_the_skype_highlighting (919) 676-1939 end_of_the_skype_highlighting
support@beisansystems.com

they were real helpfull. best bet wouls be to call the company you bought it from and let them know what point of the prosess your up to.

hears a link just incase http://www.beisansystems.com/procedures/index.html

[Blufire]

I have a rebuilt vanos unis with no transverse play on the vanos output shaft whatsoever. The problem seemingly lies with the thrust washers, both of which are new... I'm kinda stumped here.

The new intake sprocket studs I ordered from pelican are not the same as my current ones at all. They have a wider standoff that prevents the last 4mm disc from sliding down all the way against the spring plate... maybe i'm assembling it wrong, but I really don't see how that's supposed to work. Anyone take apart the intake sprocket assembly recently? The studs i'm talking about are part 11361403824.

I talked to Chris from DrVanos... in order to use the spring plate, all of the parts need to be of the updated version designed around the larger studs, and the standoffs seem to make sure the nuts go down to allow the precise amount of tension on the thrust washers.

Guess that means yet another 1-2 weeks of waiting for the part to come in...