yere1

Hey guys does Does anyone knows what is this noise my car making ( I’m gonna attach a video) it happens only for second or 2 every time I start the car after sitting for few hours and it goes away. Thank you in advance.

JTK44

Sounds like a normal 4 cylinder engine to me.

The G Man

Sounds like something vibrating at startup, not sure if thats normal.

yere1

after the first second of not sounding normal 4 cylinder engine it does sound like normal 4 cylinder engine after you absolutely right

yere1

my mechanic told me it can be the tensioners. Im just curious to know if anyone knows what exactly is or it happened to anybody

spb147

that sounds exactly like my failing cam adjusters did on w204 C250; other the adjusters, a chain tensioner that doesnt pop out immediately could momentarily cause that sound and/or a stretched chain.
take a look at this thread linked below
https://mbworld.org/forums/c-class-w...adjusters.html

fahadcdkey

It seems like the air box is not sitting / not clipped in all corners. Sometimes the filter is not sitting in its perfect spot. It probably is the worst placed air filter housing in my opinion.

AllPhonesAretap

it's definitely making a clattering noise at startup, however, it's brief, but it's clattering. How many miles are on your car and what's your oil change interval? Not what they say to change it at, but how often do you change your oil? I'd try to get My local Benz dealer to look at and have them give me a loaner car. It can be anything; Stretched Timing chain/ tensioners/camshaft phasers, anything. It's not an exhaust leak or a heat shield because once oil gets everywhere, it goes away. Try a liquimoly additive, I've personally had good results with them. If you're not within your warranty period, consider swapping the engine if fixing it is not worth the cost.

How?
could be this too
plastic doesn't sound like metal, this doesn't sound cheap or easy but I could be wrong