DoctorMesmer
New Member
I acquired a 2015 S212 E220 Bluetec (OM651) last summer – my first Merc, first diesel and first automatic car. It has 85K on the clock but a FMBSH (and was last serviced 2-3 months before I bought it).
The car runs well, but I couldn't help thinking that my engine didn't idle as smoothly or quietly as I'd expected. It's possible to feel a small amount of engine vibration through the seat at idle – and in three side-by-side comparisons with friends' diesel cars, the Merc engine wasn't as smooth as a VW CC, a Passat or a BMW 525.
I took it to my local indy who took a look under the bonnet and said it sounded and felt normal. I also took it to the dealer, whose mechanic said the same. However, when he removed the plastic engine cover, I noticed that the metal air filter cover wasn't actually screwed down – the screws were rattling in their holes. It was likely an oversight from when the air filter was changed at the service. He screwed it down and that seemed to help.
However, I reckon it still makes more noise and vibration than I would have expected at idle. I don't think it's the engine mounts, and whilst the whole engine vibrates, it seems to be greater on the driver's side of the engine (around where the air filter cover is!) than the passenger side i.e. on your left as you look into the engine bay from the front.
I concede that I'm new to Merc and diesel and in day-today use, the car seems perfect. I had expected a smoother engine from Mercedes, though – diesel or not.
So...does this sound normal (as two mechanics have said) and are Merc diesel engines just that bit rougher than VW or BMW – or do I have a possible fault. If so, what might it be?
Thanks in advance for any replies.
The car runs well, but I couldn't help thinking that my engine didn't idle as smoothly or quietly as I'd expected. It's possible to feel a small amount of engine vibration through the seat at idle – and in three side-by-side comparisons with friends' diesel cars, the Merc engine wasn't as smooth as a VW CC, a Passat or a BMW 525.
I took it to my local indy who took a look under the bonnet and said it sounded and felt normal. I also took it to the dealer, whose mechanic said the same. However, when he removed the plastic engine cover, I noticed that the metal air filter cover wasn't actually screwed down – the screws were rattling in their holes. It was likely an oversight from when the air filter was changed at the service. He screwed it down and that seemed to help.
However, I reckon it still makes more noise and vibration than I would have expected at idle. I don't think it's the engine mounts, and whilst the whole engine vibrates, it seems to be greater on the driver's side of the engine (around where the air filter cover is!) than the passenger side i.e. on your left as you look into the engine bay from the front.
I concede that I'm new to Merc and diesel and in day-today use, the car seems perfect. I had expected a smoother engine from Mercedes, though – diesel or not.
So...does this sound normal (as two mechanics have said) and are Merc diesel engines just that bit rougher than VW or BMW – or do I have a possible fault. If so, what might it be?
Thanks in advance for any replies.