Hello:

I had this ml350 Bluetec with 75000 miles. Under acceleration, the engine will present light metal clicking nois( does not sounds like the transfer case noise video I found online), it also produce a ticklely sounf like a semi or a old school bus. Is this normal for this car? I can not duplicate the noise very well .

Thanks

https://drive.google.com/file/d/1mh-uXaeMKZoE0q8ui2q92COHCPEu__Vu/view?usp=drivesdk

Does it make a rattling noise when started after sitting overnight? Could be some timing chain noise from a failing chain tensioner or a stretched chain? I think injectors can get noisy as well, but I don't have any experience with bad injectors, maybe someone with more knowledge will chime in on that.

164 timing chains will make a rattling noise that is hard to mistake when they need to be replaced. On start-up occasionally at first, and eventually all the time on start up. As tempting as it is to ignore it, get it replaced. After all, it is one of the well known 3 or 4 problems on a 164 Bluetec.