Weird rattling sound coming from under the car somewhere?

[carnufex]

So, after getting my s280 install for the last 4ish months this rattling sound has been annoying the hell out of me. It seems to come and go and I cant seem to replicate it with any consistency. SOmetimes it happens on cold starts, sometimes not. Sometimes it happens on pulls, other times it doesnt. It isnt consistent at all but when it happens it is so annoying and it really ruins the drive. I have been under the car for the last few weeks trimming spots off an exhaust hanger I saw had some rubbing, checking the heatshields push nuts, etc. Took the armrest out twice to check for a rattling bolt in there. Im at a loss for what it is, any help is most appreciated.

Ill try to add a video of it here if I can catch it

 

[slopoke]

First, I would take a rubber mallet and start tapping on stuff. The exhaust system along it's entire length would be first. Rattles are a pain.

 

[dhminer]

I had a rattle like this from downpipe hitting the first exhaust hanger. Used a pry bar and bent it a bit - problem solved.

 

[thecman02]

Would definitely second what others have said. After I installed mine I had an intermittent rattle like you. The exhaust was positioned just different enough that I had some heat shield interference occasionally. It was quiet most of the time, unless I was coming to pick someone up, or I was at a stop light with people around me with windows down.

 

[carnufex]

alright, ill pry that exhaust hanger a bit and check the heat shield for rattling thanks guys

 

[green_henry]

I had rattling with the OEM exhaust hangers because they were way too soft/pliable -- and this was before I did any significant mods. If you haven't already replaced them with Whoosh/Cobb/Mountune, I would definitely recommend doing so; I went with Mountune (but they're all very similar) and no more rattling.

 

[Sam4]

I snapped one of those pesky converter/downpipe bracket studs while during a rear motor-mount therapy session. The exhaust has been groaning at me for many miles....

 

[carnufex]

I had rattling with the OEM exhaust hangers because they were way too soft/pliable -- and this was before I did any significant mods. If you haven't already replaced them with Whoosh/Cobb/Mountune, I would definitely recommend doing so; I went with Mountune (but they're all very similar) and no more rattling.

Yeah I had this problem with the rear crossmember hitting the exhaust with the saggy stock hangers. This one is more ellusive, I will take dhminers suggestion and bend the b**** so it wont bother me anymore.