Looking for some help with engine noise. I originally thought the noise was VANOS related, see previous post VANOS rattle continues after startup, no codes
, but it is so loud that I'm thinking it may be something worse like a broken chain guide or rod knocking. Would a sticking valve be loud? this is more than a slight ticking.
It seems to be coming from the top end on bank 2 and there are no codes. When I first start up the engine it will idle without the noise until I give it some gas, then the noise is constant even when going back to idle. So far I've checked the following:
-drained oil and checked filter, no debris
-removed chain tensioner, spring was not broken although it was not tapered on both ends like the one here Chain tensioner change DIY with pics
-removed bank2 valve cover, no scoring on the cam lobes, tensioner for the cam chain is tight. I did notice there is some play on the chain that runs back to bank1, right about where #4 is in this diagram - is this normal?
RealOEM.com BMW E39 M5 Timing - Timing Chain Lower P
Any other ideas while I have this opened up? I may just bring it to the dealer and see what they come up with
update: just noticed I can turn the little 10mm coupler on the vanos gear...dont think I should be able to? as I remember it connects to the vanos unit and should be tight? I can't get TIS to install on win7 which is unfortunately all I have right now. #2 in the diagram here for the exhaust cam, you can also just barely see in the pics below
RealOEM.com BMW E39 M5 timing gear timing chain top