Engine noise 525i Vanos

[etcetera]

183k miles, has a quick knocking noise from the front of the valve cover. It's definitely not a rod knock or anything like that, kind of sounds like maybe the timing chain or maybe chain tensioner or possibly VANOS noise. What are some of the common noises in this area? What does a noisy vanos unit sound like?

When I got it it wasn't this pronounced I don't think. Maybe it's my imagination as I become more tuned into the car though.

I'll be pulling the valve cover to strip and paint it, so I'd like to take care of this if needed at the same time while it's off.

As usual, all work will be completed by me.

[NovceGuru]

I'm pretty sure its vanos noise, I had the same noise when I got my 525i with 182k miles on it, I replaced the timing chain/tensioner/every gear/guide and it still makes the noise. My $.02

NovceGuru

[etcetera]

Thanks for the input.

Any chance of a catastrophic failure of the VANOS unit?

[shrike071]

+1 for Vanos noise... I have yet to replace mine, either...

[RobPatt]

literally what's rattling when the board refers to vanos noise?

I thought it was an eccentric or something, that upon a certain RMP or oil psi was forced into the eccentric (or something) that engaged into the intake cam gear and progressively twisted it a few degrees thus advancing the timing

so when not "on the vanos" what's the part that rattles?

just wondering, guess I don't know how it works....

cheers, rob sends....

[bsell]

I'm pretty sure its vanos noise, I had the same noise when I got my 525i with 182k miles on it, I replaced the timing chain/tensioner/every gear/guide and it still makes the noise. My $.02

NovceGuru

See, my '95 (09/94) 525 has what I would call 'a worn guide' noise/groan going on. I have yet to take to the local BMW guru for an estimate but would hate to spend the cash changing out the timing mess on an engine with 100,000 kilometers (60,000 miles) on it.