DarCKnight

Once the engine has been ran (normal driving) and parked for like 10 mins and you go to start and leave (put in reverse or drive) I hear this awful rattling noise. It sounds like a worn-out diesel engine. If you put it back in park to try and find out where its coming from it goes away. It only last for like a minute or two but is very loud and sounds horrible. I looked at all the heat shields and exhaust manifold and pretty much anything that could be loose and didn't find anything. It only happens when the engine is warm and only in a gear. It shifts smoothly and I haven't noticed any performance lose or bad mileage so I'm stuck.

Anyone have anything similar happen or have any ideas on what it might be. Any and all input is much appreciated.

Buellwinkle

Could be your motor mounts are shot. Put it on jack stands and have someone put in drive while you look and listen around. From the outside you'll be better able to pinpoint it.

DarCKnight

Thats about the only thing I saw when I looked. Every time the engine was revved it moved quite abit. It looked odd to me. Is that a common thing for a 05' C230 with 56k ?

Moviela

Pretty common. German luxury brands use rubber that is Shore A 75 for motor mounts and guibo's (fles disc) which is softer than American iron that tends to use Shore A 90 which is stiffer. The softer material wears out faster. The Germans have also had trouble making the material mould to metal inserts, so a common failure is separation, rather than shearing through the center. The German Engineers defend themselves by pointing to the poor condition of US roads and highways as the reason for higher failure rates. I have to agree, roads in the US have been in a decline for decades.

rtking

I had this very same issue addressed this last week. It turned out to be the supercharger belt tensioner that was the culprit. Dealer replaced it under my extended warranty. Outside of warranty, I think the part would have cost $260 + labor.

DarCKnight

Thx for the input. I'll check both of those issues

C230 Sport Coup

I replaced my belt tensioner at one point, yeh, it was shaking and causing the belt to make noise, but it pretty obvious where it was coming from.
There was a video of that around somewhere, though it may have been on
a now defunct site.

Take a video if you can and post it if you can't figure it out.

jfabes

^^^ true that....same here, had mine replaced about 2 months ago. horrible sound....and it got worse when you would put on the a/c due to the extra belt load.