In the 5 years or so that I have owned my 2.0 litre Z3 I have always had an annoying little noise/rattle/buzz from the engine at about 1800 rpm for a few minutes when the engine is cold. As soon as the temperature gauge gets to normal there is no noise and the car runs fine. I have always suspected the Vanos as the noise seems to come from that area and just over a year ago, at about 90,000 miles, I renewed the seals in the vanos with seals from a company which I believe is called 'i6' anyway not Beisen Systems. I was surprised at how bad the original seals were, the inner rings which are meant to be elastic were rock hard and just broke up into several pieces. I checked the end float on the thrust bearings which measured about 4,5 to 5,0 thou which I thought was a reasonable figure. I was afraid of damaging the pistons by dismantling the bearings as the threads were so tight so I left them. The car was quite a lot smoother but the noise was still there. I have just bought a used vanos unit with a view to rebuilding it with no end float on the thrust bearings as Beisan Systems say there should be a slight pre-load.
The car which the used unit came from was not making the noise but the thrust bearings have the same end float as mine, about 4,5 to 5,0 thou. The question I'm beginning to ask myself is 'am I wasting my time'. Has anyone else experienced this problem or rebuilt a double Vanos unit, is the noise something else entirely.
Vanos!
Re: Vanos!
I`ve looked at a few videos on youtube about repairing noisy vanos units and they all focus on just replacing the seals, none mentioned replacing the thrust bearing. New seals seemed to cure the noise. Maybe you have a slightly worn water pump bearing, my water pump was noisy but quiet once warm but once replaced all noise went away.
Re: Vanos!
I replaced the water pump some time ago as a precautionary measure but no difference to the noise. I can't believe no one else has experienced this problem on this site.
This article from Beisan Systems shows the procedure, I'm planning to get the spacer rings surface ground to remove the end float.
http://www.beisansystems.com/procedures ... cedure.htm
I will post back when finished one way or the other when/if I get this done.
This article from Beisan Systems shows the procedure, I'm planning to get the spacer rings surface ground to remove the end float.
http://www.beisansystems.com/procedures ... cedure.htm
I will post back when finished one way or the other when/if I get this done.
