boom132

My first Mercedes... 2005 C230K... I've been a Saab 9000 Aero man for years... got a great deal on this car, and I've been reading this forum for days now.

Question though... the exhaust/engine noise is horrible inside. The exhaust looks like its all there... I mean seriously, I have to turn the radio way up, and have to talk very loud pretty much all the time to passengers.

On a side note, doing 80 on a straight piece of road, no incline, and the tach is at 3250... feels like it should drop down a gear... anyone else experience this? Or normal??

I can't wait to learn more about this car... it sure is fun to drive!

sammydragon3

your car is a 5 speed

and like u said at 3200 rpm is about right at 80

your car has a supercharger so accept the noise

boom132

Thanks for responding Sammy... I've been used to Turbos (Saab Aeros)... just getting used to a supercharger!

I don't mind the supercharger sound, but its the exhaust that just seems overbearing... Is there a diagram somewhere that I can see the stock exhaust layout?

I'm wondering if something is missing...

(Still reading through this forum).

havoc_vulture

Do you mind trying to take a video with windows up and everything to hear it first hand?
my car did make noise but nothing to bad
layout of the exhaust would be the
header
two cats with o2 sensors
resonator
pipes to end
and muffler with tip

sammydragon3

only has 1 cat

boom132

I'll post a video tomorrow... I also have a lot of rattling going on underneath. I will jack the car up tomorrow and take a peak underneath... I'll try to post pictures of the layout as well...

Thank you both...

havoc_vulture

https://mbworld.org/forums/c-class-w...t-diagram.html
this should help

boom132

Havoc, thank you so much! That really helped... is it common practice (due to cost), to go to a header and remove that first cat in some way?

I can only imagine how expensive it is to have an integrated manifold/cat replaced...

Glyn M Ruck

I'll bet someone has fiddled with the exhaust. It should not be overpowering.

LILBENZ230

The RPM level you say is correct for the 230K. The exhaust and engine are louder than you might expect but not overbearing. My car is louder in the cold weather.. always has been, not sure why.

Check engine and transmission mounts. When my car had a collapsed transmission mount it made the drivetrain noises louder in the cabin.. Mine is still suffering from this, do flex discs cause noise?

tommy

On these models, it's common practice to be afraid to do any mods. Do a search here, but I THINK that there's only been an OBX header that's been developed, and it has questionable quality in the welds.

Yes, if you have to replace the cats, stock parts will be over a grand. I've had success with the recent Maglaflow cat on my car, but we've got different models, so I'm not even sure if there is an aftermarket cat made for your car other than a generic one you'd have to have custom tubing worked out on, plus a bung for the sensor, and not sure how the ecu would handle, etc. In short, it's dicey.

boom132

I think I have finally decided I wasn't use to the sound at first. I've been driving a really quiet Saab for a while... I'm getting used to it now. Everything looks untouched; original parts etc. Perhaps some of the joints may need to be ratcheted down again.

I will definitely take a look at the tranny and engine mounts. Maybe that noise is reverberating through?

Thanks for all the help guys! You ROCK!

Glyn M Ruck

Go drive another one on a dealer lot for piece of mind.