[Pas]

Hi just wondering if anyone else is experiencing a similar problem. We've owned our GLC250 (petrol) for a year now, the engine has always been a bit noisy during idle a bit like a rattling sound, but in the last couple of months it has got noisier during cold starts, it sounds like a loud diesel motor.

We've taken it back to our MB dealer a few times now, but have advised in the first instance that the petrol engines are now using the diesel injector technology which makes them noisier and the latest sound is the actuator rattling due to the design and positioning of the turbo. They showed me another GLC250 that was brand new with a similar issue.

Has anyone else had a similar problem and if so were they able to rectify it?

 

[MercNut]

I have the GLC300 with the 2.0 litre, direction injection, turbo charged engine and it sounds a lot like a diesel as well. I find it quite noisy in all conditions but even more so when in cold mode after a cold start.

My neighbour has a GLA250 with the same engine and it sounds exactly the same as mine. When he first got it (about a year before I got mine), I thought it was a diesel. I was surprised when I later learned it had a gasoline engine.

Prior to my GLC, I had an Infiniti M56 with a direct injection 5.6 litre V8. It was also very noisy during cold starts. So much so, I could hear it switch out of cold mode into normal mode as it quieted down considerably when it did.

I'm no expert but I believe direct injection engines tend to be noisier compared to non direct injection ones. I believe it's mostly due to the much higher injection pressures (compared to multi-point injection or throttle bodies) and the related high pressure injection components, notably the solenoids/actuators/piezos.

I considered the GLC43 AMG but went with the 300 instead because the AMG spec'd the way I wanted would have been a factory order with a June delivery date whereas the dealer had the exact 300 spec I was looking for in inventory. I wished I had gone with the 43 because I don't like the sound and "buzziness" of the 4 cylinder at all. I've always had V6's and V8's and much prefer the sound and smoothness of them.

 

[MercedesTheBest]

i have noticed the same thing. gets better when it warms up compared to being cold. its a rattle trap, they all do it, all new cars do it. it is just the way it is with the engines now-a-days. my 1995 SL500 with 5.0L V8 sounds a **** of a lot better then any new car today.

 

[CRNCYX]

Maybe a different grade of oil will solve it? In older cars I noticed that helped and i'm talking about vehicles 10-15+ years old. Not exactly something we want to try here unless MB has some recommendations on oil we can use. Sometimes they provide us with winter rated engine oil.

 

[desal]

I just picked my GLC300 a week ago and stopped at the dealer today to ask about the engine noice. I too was told it was the injectors. I had a 1989 gas MB that sounded like a diesel. I had that car for 10 years with many oil changes and it sounded the same when I sold it at 110,000 miles as it did when first bought. I used a few different grades of oil including synthetic and the noice never went away. The good news is the engine never skipped a beat.