My 1999 Saturn is making a rattling noise on passenger side?

Question

I have a 1999 Saturn SL and recently it started making a rattling noise on the passenger side, but usually only while I'm stopped. When I accelerate or pop it into neutral while stopped the noise will stop. It seems to be getting louder also. Any ideas?

Answer 1

It's your catalytic converter.

That's a part of your exhaust to make your car cleaner.  It has a honeycomb of ceramic inside it that restricts air flow and therefore increases the exhaust temperature.  Increasing the temperature burns off all sorts of nasty elements.

Eventually the honeycomb gets clogged up, once it's clogged it will break up and what you're hearing is the ceramic rattling around inside it.  This problem will snowball until it gets very clogged.  Once it's really clogged up the engine will run funny and stall out--let it go too long and you'll need to get towed in.  Want to be positive that's what it is?  Park your car with the engine idling.  Get out and put your head under the passenger side of the car near the door and find the exhaust.  Look for a box shaped part of the exhaust, it'll probably be easy to find because it will be the one rattling!

This should be around $250 to get replaced at a muffler shop.

Answer 2

Possible loose exhaust..take a peek under your car while it's running and see if you can see what's rattling.

Answer 3

If you are in drive with foot on brake idling and it rattles, and then you put it into park or neutral and it diminishes, the motor mounts need attention.