start by checking a/c compressor.
There is a baby under the hood.
bad transfer case
your Imagination.... :)
If it's a type of clunking noise, check your gearbox. If it's some kind of rattling, check your hubcaps.
An air conditioner should not smell like smoke when turned on (or when turned off). I would have to suspect that the electrical insulation is burning.
Check to heat-shield at the catalytic converter because something is loose
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.
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.
I had the same question until my wife noticed the tag rattling as I took off, I put 2 rubber pads behind it and the noise stopped! I had the same question until my wife noticed the tag rattling as I took off, I put 2 rubber pads behind it and the noise stopped!
Possibly bad throwout bearing
It's probably your shock mounts, I had the same problem. The noise went away after I replaced the shock mounts.
Well without further analysis or information, a short answer would be that your engine is BROKEN.