06 M45 - Rattle at startup

[Cp13]

My 06 m45 makes a quick rattle noise when I turn it on any thoughts ?

[EdBwoy]

Assuming this noise is coming from the engine bay, how many miles on your car? Also, have you checked your oil levels recently?

[Cp13]

There's about 135000 miles on it and yes I did. I checked engine oil are there others

[EdBwoy]

I was trying to eliminate the timing chain as the cause of the rattle. In other engines when the oil was low the chain tensioners wouldn't function correctly.
So this rattle goes away as soon as the car is fired and running, huh? Does it ever return when you hit the gas?

[Cp13]

Yeah it just rattles when I turn it on but then it goes away immediately. And no I haven't noticed it do it when I press on the gas. The only problem I have with pressing on the gas is a spraying noise

[EdBwoy]

What grade of oil do you use?
And can you record a video of this spraying sound and the location it comes from?

[Cp13]

I used 5-30 synthetic oil
For the spraying noise I could possibly try but the problem with that is. it only sprays under acceleration. So it was would have to be moving

[EdBwoy]

How about if you left the car in park and gave it gas, would you hear the spray? If it has to be moving, then I'm thinking something like the brake shields would be scraping... which you should hear even if you're not on the gas.

I use 10w40 for most of my vehicles. Remember that tensioner issue I mentioned? One way we'd try to get around too much rattling was to use thicker oil.

[Cp13]

Yeah it doesn't do it only when am driving. I don't really hear it when not pressing on gas only when I give it gas you can just hear a spraying noise