E90 ticking

[MrGreedy]

I am seeking assistance from anyone who can provide help.
I possess a 2006 E90 M47 that produces a ticking noise when the vehicle reaches optimal temperatures.
A few months ago, I operated my vehicle with low oil pressure, and a friend suggested that I might have caused low-end knock. However, after changing the oil and filter, we did not observe any metallic particles in the filter. Additionally, we placed four strong magnets underneath the oil during drainage and found no metal shavings. The ticking noise did not entirely correlate with the engine revs, leading us to conclude that it was due to chain slap. The vehicle just underwent maintenance, including the replacement of the timing chain, tensioner, water pump, steering pump, auxiliary belt, and all gaskets, approximately two weeks ago at a mileage of 165,000.

However, the noise persists. We have also eliminated lifter tick, as it is only audible from the bottom of the engine, predominantly on the driver's side, and cannot be detected with the hood open. I have included a link to my YouTube video at the end of this post. Thank you for your assistance; I recently spent £2,000 to eliminate this sound and was informed by the garage that it was chain slap, which is quite frustrating. To be fair, the car drives well and accelerates smoothly, but I detest this noise. The most accurate description of the ticking sound is that, while idling, it produces a characteristic diesel tractor "duhduhduh" noise, with the ticking occurring in varying rhythms such as "tick.......tick tick......tick tick tick tick.............tick." However, upon revving the engine, the ticking sound synchronises with the vehicle's operation.

[IrvesBMW]

Perhaps a minor fissure in the catalytic converter or manifold?

[MrGreedy]

I have not yet inspected it; I need to elevate it up the ramp for examination. However, it is likely that this would produce a rattling noise at startup, correct? Is it not when the engine is warm?

[WordSmith]

I viewed a YouTube video suggesting that the ticking sound may originate from the hydraulic lifter. To alleviate the issue, one should start the engine and maintain it at 3000 rpm for three minutes; some claim this resolves the problem, making it worth attempting.

[MrGreedy]

From the bottom of the engine? Is it only when the temperature is warm?

[WordSmith]

Uncertain about the location of the component, comments on that YouTube movie indicated that the issue is not exclusive to BMW; other owners have attempted solutions, and some individuals reported success.

[MrGreedy]

I will attempt it and provide you with updates.

[MrGreedy]

Additionally, here is the video.

[MrGreedy]

 

[Screwdriver_1]

It appears to be an issue with the exhaust or manifold; nonetheless, it would be advisable to inspect it further if you can access it on a ramp.