Vanos Rattle

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Zedbedee
Joined: Sun 15 Mar, 2009 20:04
Posts: 152

  Z3 roadster 2.0
Location: Yeovil

Vanos Rattle

Post by Zedbedee » Sun 02 Nov, 2014 16:07

Several years ago my BMW 2,0 Z3 developed an annoying little chattering rattle noise at about 1800 to 2000 revs when cold. According to Beisan Systems this is caused by a combination of end play in the Vanos thrust bearings and wear in the helical splines which link the Vanos to the camshafts. Beisan say that eliminating one of these wear areas will stop the rattle and sell ‘special’ bearing spacer rings to remove the end play from the bearings.
I decided to get a spare Vanos to rebuild at my leisure and bought one on Ebay for the princely sum of £35 delivered. There are excellent instructions showing how to remove and replace the Vanos unit as well as replacing the seals and fitting their own anti-rattle spacers at ‘http://www.beisansystems.com/’ and I have no intention of trying to improve on these. However, I believe my way of eliminating the thrust bearing end play, which causes unwanted noise, is both efficient and low cost. In sharing this procedure, which worked well for me, I take no responsibility for any damage you may cause to yourself or your car in doing this.Image
Vanos unit as received.
After stripping and cleaning using paint stripper and brake cleaner to remove the dirt and varnish the parts were scrubbed in hot soapy water and blown dry.
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Cleaned parts and all in excellent condition other than the seals and the bearing rattle.
Shown here temporarily assembled.
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The spare splined extensions on the pistons were installed temporarily to make it easier to measure the endplay
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Two pieces of hardwood were clamped together and a hole cut through the two parts using a hole saw the same size as the pistons. Luckily I already had a saw of the correct size but they are easy to find and not expensive.
The wood clamps were used to hold the piston firmly in a vice without marking it. Then a couple of serious blows with a lump hammer on an impact wrench had the bearing retainer loose. Take care, these are VERY tight.
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Couldn’t show the hammer as I was taking my own pictures but I’m sure you get the idea.
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This shows the piston internals. The two bearings and the thicker centre plate sit inside the spacer ring in the centre of the picture. The two larger washers then sit either side and are clamped by the threaded retainer at the bottom of the picture. The thicker centre plate rotates with the camshaft and the spacer ring and outer plates stay clamped to the piston and do not rotate.
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Clamp together the centre plate, the two bearings and the end retainers and measure the thickness.
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Then clamp together the spacer ring and the two end retainers and measure them. The difference is the end play. Here it’s about .006 inches (0,152mm). Not a lot but enough to cause an annoying rattle when the camshaft spline drive is also worn.
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I then used 400 grade followed by 600 grade wet and dry on a sheet of glass to keep it flat and removed the excess material from the spacer ring. This is quite time consuming but it works well and you are not likely to remove too much metal. Having said that you will be wise to measure the thickness of the spacer quite frequently! You should remove all free play but make sure the bearing rotates when assembled.
If you don’t have a micrometer a digital vernier calliper will do just as well if not better and they are very cheap. At a push you could just remove metal until there is no sign of a rattle when the parts are assembled dry.

I then rebuilt the unit using new seals following the instructions on the Beisan Systems website.
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Rebuilt Vanos assembled to engine. Makes the rest of the engine look very dirty!!
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Ready to fire it up. And no rattle. Whoopee!
Note!! This is my first post using Photobucket. If it doesn't work, apologies....
Last edited by Zedbedee on Sun 02 Nov, 2014 18:23, edited 1 time in total.

Zedbedee
Joined: Sun 15 Mar, 2009 20:04
Posts: 152

  Z3 roadster 2.0
Location: Yeovil

Re: Vanos Rattle

Post by Zedbedee » Sun 02 Nov, 2014 16:08

Bugger!! Why don't these pictures display?

Kondor
Joined: Fri 18 Jul, 2014 21:45
Posts: 33

  Z3 roadster 2.8

Re: Vanos Rattle

Post by Kondor » Sun 02 Nov, 2014 17:15

Zedbedee,

When you want to link a pic, you need to first click the "IMG" button and then paste the link between the img tags.

Hope this helps!

Oh, and I see you're in Yeovil?

***waves from Bridgwater*** :thumb:

Zedbedee
Joined: Sun 15 Mar, 2009 20:04
Posts: 152

  Z3 roadster 2.0
Location: Yeovil

Re: Vanos Rattle

Post by Zedbedee » Sun 02 Nov, 2014 18:33

Thanks a lot Kondor!!
Now I see how it's done. I've had my Z3 for nearly 5 years now and that little rattle was really annoying me. I really don't think it was doing any harm to the engine but glad it's finally cured.
I live nearer to Crewkerne than Yeovil but I've just about given up waving or light flashing as no one seems to return it.
Anyway now I have mastered the picture thing I'll try another one.
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