Gritty feeling engine!
I think the 3.5L is the worst of the bunch. I still think that the 90 degree V6engine block is the wrong direction for Mercedes to follow, just because of cost reduction having to assemble in the same assembly line with the V8 engine block. BAD IDEA! The in-line six was super smooth and quiet! Really missed it!!
Johf
2008 C 300 4 MATIC Luxury

I think the 3.5L is the worst of the bunch. I still think that the 90 degree V6engine block is the wrong direction for Mercedes to follow, just because of cost reduction having to assemble in the same assembly line with the V8 engine block. BAD IDEA! The in-line six was super smooth and quiet! Really missed it!!
Johf
2008 C 300 4 MATIC Luxury
You may be interested in some of my postings in the thread below regarding engine balance, vibration & resonance. Watch the crank pulley on your engine. They have been known to give trouble.
The old 280 E Twincam 6 was a gem!
https://mbworld.org/forums/c-class-w...iscussion.html
Last edited by Glyn M Ruck; Feb 5, 2009 at 02:05 AM.
I sold my C 240 to my sister and she is driving it now. The engine has about 165,000 km on it. The only problem with the engine is that it is consuming oil for whatever reasons. We have been following the oil change instruction by follwoing the trip computer system and use only susthetic oil.
I do not think the 90 degree V6 engine was designed for dual overhead camshafts. I believe the design of the 90 degree V6 engine block was originally only designed for single overhead camshaft. The dual camshafts may be the reason for the inherent noises and vibrations.

You could be correct re cams - but damping cam resonance is a well known science today so no excuses.
My car has only done 49,000 Kms - but long term I have my eye on a new W204 350 Elegance once they are in mature production. I never buy a model in it's first few years - I'm old school I guess. I have such a good car I'm worried the next time round I might not be so fortunate. All that's ever been done is a 5 cent washer on the gearbox plug because we had an oil weep & castor bushes. Not because they had failed, but because they are known to fail & my service manager wanted to get redesigned ones on the car before the service plan ran out. Otherwise the car has been faultless.
Last edited by Glyn M Ruck; Feb 6, 2009 at 04:53 AM.
I am not so sure with a modern fuel injected engine but the older carburetted engines which blew smoke after a trailing throttle down a hill had worn piston rings. ie the high manifold ( butterfly shut) vacuum above the piston drew up the sump oil & mist through the worn rings.





-Ryan
At 20 000KM 1st service they changed the L5 sensor, relating to a complaint about rarely cranking but not firing up the engine, and error messages related to this.
They the upgraded the SW & changed oil.
Getting home I noticed engine felt more roughly after startup.
After 3 000Km i noticed the sounds of exhaust as on warmup 1st minute, becomes throughty, sounds like compressor kicks in or valve in exhaust opens and closes, revs go up & down a bit, then steady, and then it starts again, now this all happens when egine is hot after at least 50KM drive.
It never did this before, and was smooth after warmup[1min].
What could cause this ?
The Best of Mercedes & AMG
I don't notice any odd engine noises per se, but I feel an almost "gritty" feeling through the gas pedal and steering wheel, particularly at lower speeds when coasting during city driving. I haven't noticed the problem at highway speeds.
To provide context, the feeling actually made me check whether my emergency brake was slightly engaged. I haven't noticed excessive brake wear or anything and I don't believe the brakes to be the culprit -- but that's the "feeling" I get through the pedal and steering wheel. FWIW I'm only getting about 15.8mpg, though I'm doing >80% stop/go city driving the last few weeks.
This thread discusses a transmission mount; any other thoughts? I'll likely be visiting the dealer next week to have it checked out.



