A possibility may be a loose catalytic converter shield, or loose muffler hanger or clamp. Usually a noise like this is caused by something that is loose and vibrating. These issues are usually not complicated or expensive to fix.
If you're talking about the engine making rattling noises, the timing may be off, or it may be running too hot. Also, make sure you're using gas with the proper octane for your car. An engine noise like this is called "detonation". Detonation can cause engine damage if left untreated long enough.
there is a rattling noise in the area of the serpentine bell
It will normally start with a leak at the pump. If the impeller breaks you will hear a rattling noise at the pump.It will normally start with a leak at the pump. If the impeller breaks you will hear a rattling noise at the pump.
your Imagination.... :)
There are a few things that might cause an air conditioner to make a rattling noise. It could be that the there is dirt and debris in the cabinet. If this is the case, cleaning the cabinet should stop the rattling. The reason could also be loose panels on the cabinets. The fan could also be bent and no longer straight.
Your Mazda Protege might make rattling noises when parked because of a loose or damaged muffler or even body panels that are loose. It might also make a rattling noise because of a damaged motor mount.
assorted loose things
start by checking a/c compressor.
If it's a type of clunking noise, check your gearbox. If it's some kind of rattling, check your hubcaps.
I'd like to know too! Mine does the same thing - it makes a rattling noise upon startup that goes away after 30 seconds or so and isn't present while driving or idling.
its because you must have something lose on your scooter try tightening all the bolts and stuff.
poo
Possibly bad throwout bearing