Loud rattling from top of the engine under low revs

[Pieter B.]

Hello,

K12 with 140,000 km. Timing chain replaced around 100,000.

It has started making a loud rattling noise from the top of the engine at low revs. It appears to be from under the rocker box cover.

Anyone with any ideas? The car revs fine, and the noise diminishes as revs increase. It also does not appear to be directly proportional, though it does change (quieter) as revs go up.

Thanks.

Youtube of engine noise

 

[MaxWheeler]

Videos can be misleading but it does sound quite bad... Take off the ancillary drive belt and start the car and see if the noise persists... If it doesn't, check the pulleys for lateral play and noise when spun

If that sounds a bit much for your skill set then off to the local garage might be your least stressful option

Sent from my COL-L29 using Tapatalk

 

[tdp2612]

Is it loudest around 2500 revs at very low load?