W205 c200 petrol engine noise

[Chadcombe]

Hi all,
First time posting.............not sure if I'm doing this correctly!
I have just bought ( 28 days ago) a c200 W205 petrol, 2015. Going back to the dealer for a new back box next week as existing one has "loose baffles", car has covered 35k! Anyway, my question relates to a "breathy/tinkly" noise from the engine that I can hear from the drivers side, just behind the bulkhead. Increases with engine speed. Does anyone else have experience of this? When i listen to the engine on tickover, I hear the same ticking noise that increases with throttle along with an air suction sound , my old W204 diesel was quieter ! Again I would really appreciate any input from anyone experiencing something similar. Am I being too picky? Until Monday I can still reject the car and get a refund ( 2015 Act), not sure if I can live with this noise. It may well be that some insulation is loose inside the car/footwell, again anyone had experience of this ? many thanks........................Gary

 

[Rubyred]

Sounds like the loose baffle noise is being transmitted along the exhaust system, or you may have some thing else loose on the system. Get them to check when they do the rear box.

 

[grober]

MB dealer or OTHER? if in doubt get a knowledgeable third party MB specialist to inspect the car/ assess the problem to see if rejection is necessary
known problems
https://www.motorreviewer.com/engine.php?engine_id=176

some cars had problems with the high pressure fuel rail pump iirc? its at the rear of the engine

 

[markjay]

It's the M274 2.0L engine... not many common issues with that one (other than thermostat failure). Can't offer advice I'm afraid. Can you ask the dealer if they have another similar car (W205 2014-2018 petrol) on the forecourt, so that you can listen to it and compare?

 

[Chadcombe]

Many thanks for the replies, really appreciate the time taken. It's from a Vauxhall dealership not MB so can't compare. I've found a video on line showing that the M274 is quite "tappety" , I'm beginning to think Rubyred may be correct in that the exhaust rear replacement may help....think I'll hopefully see if any other members have further advise then have a think over the weekend. Graeme, many thanks for the link, really helpful.