luthfisudjana

hi everyone. I am a new guy in this forum, made this account because I have questions regarding my diamond silver c350 coupe. It's my first car so I am pretty meticulous about small details of this car. I've got it for around 4 months, bought it as a CPO. So here are my questions:

1. Every morning when I cold start of the engine, I got around 11-13 mpg. Include city driving, the highest figure I get is around 15-16. Is it normal? Or is it a sign that I should perform service A/B asap? (Dirty oil maybe?) I maxed out only 27mpg when highway driving from San Diego to Los angeles. Can it be higher?

2. There is a rattling sound in the engine at times when I start the engine (warm start), but it goes away seconds after. Is it a problem?

3. At the back, there is like a plastic noise everytime the bass in audio kicks in. Any of you c coupe owners experience the same problem?

looking forward to responses from you guys. Thank you!! Oh ya and here is the pic of my first love 🔥

ShazV6

Hello and welcome to the forums. To help answer your questions:

1-15-16 MPG city driving is horrible. I easily get 20-22 and i drive very spirited. I get up to 29-30 mpg on the highway and mind you my car is Eurocharged tune.

2- Rattling sound i get more of a little ticking sound. It does go away after a few seconds of warming up. Is it a ticking sound or rattling? Just to confirm

3-As far of this i do not have any of that issue. Sorry about that

I hope this helps. Any other help needed id be glad to help. BTW she looks beautiful!

luthfisudjana

Thanks for your answers!!
So is it completely bcos of my driving style that i get low mpg figure? Before i even start driving, it always shows 11.8 mpg after cold start. Any recommendation on what should i do?

For the second question, yes it may be that kind of sound. But to me it sounds like a metal chain breaking loose for a second. Do you hv any idea what that's about?
Thanks!

ShazV6

It will always show 11.8 after you start the car. As to why you only get 15-16 mpg after warm up and driving it could be becuase of driving habits. Just drive normal for about 200 miles and see your MPG.

As far as a metal chain breaking loose that's not good. Id take it to the dealer asap.

Atlas Grey

Reset your gauge and see what it looks like when you get to work. I drive like I stole it so I regularly see 11-13 MPG in the city. It's also a lot of traffic and stop and go which doesn't help. I get around 25 on the highway, again I drive significantly faster than the posted speed limit.

nexspy

Whats up man. I had the same problem with my 2013 c300 sport. There was a weird ugly knocking noise at startup. After doing some research and taking it to the dealer the problem was that the chain tensioner needed to be replaced. Fully covered under warranty and i think a lot of 2013 mercedes models have this problem. If you search on google "LI05.10-P-056435" you'll be able to find some forum posts on it and also the xentry pdf for the fix. If you have any questions message me dude.

Eric.i.gonzalez

I know that this is a little off topic, but I have a noob question also. I own a 13 C350, also. My question is about the engine designation. Would I have an M272, or something else? Thanks guys.

As far as the ticking sound, I think it is a common sound with direct injection motors. I've driven other Merc DI, and Mazda DI, and they both make that small ticking sound. Never had an issue with performance though.