Hi all,
Been looking out for a nice M3 evo over the past week or so.
Seen 4 now, all very nice cars, well looked after, all drive and go well, milages varing between 60 & 115 K. ALL of the cars i have looked at i have walked way from,:frown The vanos is loud! It is the same Evey time, start car from cold, no noise, go for test drive, come back, lift bonnet vanos makes loud growl as revs drop from 2 or 3k.
Is this the sign of over worn, knackered of just perfectly normal!? Am i right to walk away? Or am i being over cautious.:confused
Any advice please
hi Steve
Are you sure the noise is the Vanos and not noisy hydraulic lifters?
The 'tappets' on a lot of BMW engines can get a little noisy after a while and they are technically meant to be checked, and adjusted by reshimming every 15k miles iirc.
COuld be wrong on the interval though.
With regards to the vanos
Have a read of this web page for the S50 b32 (m3 evo) vanos units and the service and prevention/repair of them
Its an easy job to change the bolts and filter etc but it wont cure a noisy vanos.. just may prevent it from getting worse.
http://mukerji.co.uk/category/vanos/
(thanks to Neil Mukerji for the write up)
Some further info by someone with a noist dual vanos unit
+1 Good advice, one of the first things I did. The TIS also describes this procedure. The torque is also critical, too much and the system is weakened due to deformed threads, too little and you have vibration failure of the bolts. I believe replacement bolts are also much stronger.
As for the growling etc, I recently stripped down my vanos looking for the source of the noise and any solutions.
This unit is NOT weak in any way other than with the piston seals, and even then only on the exhaust side, which is where I believe the real issue is. Otherwise the contruction (by rolls royce) is very robust.
The piston seals on the inlet side consist of an energizing o-ring with a square section seal over it-standard hydraulics.The good news is that the seal is retained by a separate end peice, the whole piston assy is then retained on the actuating shaft with a nut. The seal is easily replaced, but needs to be specially manufactured, as BMW don't sell them individually.
Now the really bad news is that the exhaust side piston is for all intents a one peice construction. There are two seals of the energiser o-ring type. They cannot be removed without damage. New seals cannot be installed since they can't be bought, and given the depth of the grooves I'm not sure if the piston was a two piece and then assembled.
This is also the side where the seals wear most.
So a solution may be if someone has a spare exhaust piston, it and the seals can be copied on CNC .
Maybe others have more info to share, it would be good to find a reasonable solution, the US have Dr.Vanos.
Was the Vanos noise like this?
http://www.youtube.com/watch?v=QK5hKIcytrc&feature=related
Also, heres the only place I know of that sells new vanos (reconditioned and on exchange basis) for a fraction of the BMW scam price for a new unit
http://www.drvanos.com/us_dual.htm
In summary though, a little vanos growl is to be expected on pretty much all 3.2s (as you have found)
if you can find yourself an Evo that has had a replacement vanos (with OEM BMW invoice to back it up) that would put your mind further at ease.
but to be honest, if the car is a really good one, you could always use a little vanos growl to knock the price down a bit..
And then if you do the service listed in the first link above, its very likely the vanos will keep running sweetly for a looong time
