No way of telling you without hearing it and seeing it. Have a trusted mechanic inspect the car for you before you get stuck on the road.
Depends on where the noise is whats making the noise. Can you be more descriptive of where and what?
You haven't by any chance dropped something down a sparkplug hole! Small nut or bolt!
Why is your 1993 Altima Nissan making a clicking noise but does not start?
bad throw out bearing
if it's a turbo check the turbo
My 1997 Honda CRV is making a rattling noise when driving in rough roads
Check to heat-shield at the catalytic converter because something is loose
Inspect the catalytic converter heat shield.
The rattling noise is in there so you can move the head around.
You may need a wheel bearing or a tire rod end.
Perhaps heat shield on catalytic converter?
it may be your tire alignment. your tires may need to be re-aligned. a couple of months ago my car started making a rattling noise when we would go about 70 mph on the highway. we found out are tires needed to be aligned again.