Check out both videos I've listed below and tell us which one fits your problem.

Timing chain guide rail failure, page one of my post - http://www.xoutpost.com/bmw-sav-foru...my-pocket.html

On second thought, if that is the sound your engine is making I would NOT run it even to check the replaced tensioner. Why? Because when you replace a tensioner and start the car, it takes several seconds for it to build up oil pressure to "tension" the chain. And, in those brief seconds if your guides have started to disintegrate it could give the chain even more slack which might allow it to jump some teeth which would be very bad. I'm not sure about this, so hopefully some others can jump in and give us their thoughts.

Youtube for "vanos rattle" - hood rattle 2 - YouTube

I know both videos sound similar and I guess the best way I could describe the difference is that a timing chain guide rail failure sounds like an old Ford model A and you can hear it from 20ft away and the vanos rattle sounds like a diesel and is not that noticeable until you get fairly close.

I had an indy shop change my oil and had the same problem on start ups. They told me that they used the recommended oil but they did not. I changed the oil again using the correct oil and the noise went away.

Went and looked at a 540 M62 that a friend was interested in picking up, super-clean, low miles. I informed the owner that the noise on start up was worn out timing chain guides, friend bought it dirt cheap, oil change with the correct oil and noise is gone, runs like a date-raped ape. These motors are hyper-sensitive to oil viscosity!

Hey, guys! Just found out that my wife wrote the incorrect info for the oil change and after pricing the oil and filters there's nooooo way they did my oil change for $40!!!

Sounded exactly like mine did when my guides broke one cold morning last year! :(

:iagree: