QUOTE (scratch714 @ Aug 29 2011, 03:22 PM) <{POST_SNAPBACK}>Just bought a used 2004 S60 with 92K. Ran great then one day, woke up, started it, and it ran terrible. Changed plugs. No help. Bought an ACTRON pocket scanner. Shows P0300, P0301, and P0302..misfires.
I also get a burning smell when the car is idling.....which didn't exist until it started running bad. One last thing...I hit a pothole in Charleston, SC that jarred the car so bad the linkage on the driver side door handle popped loose.
Had to pull the panel and fix it. The next day, the car started running rough.

Any ideas?
check your relays and fuses they may have popped out.

 

Burning smell like electric burning? Coming from engine bay, cabin? I'd remove the spark plug/coils cover, run the engine at night and look for arcing.

 

Thanks friends.....cylinder 1 spark plug coil. $72 for part.....$80 for labor and I'm cruising again. Next time I have a bad coil, I'll change the remaining 4 all at once...easy to do. Wish I would have known more before I sought out the mechanic...but he was a good guy...taught me a lot.

 

QUOTE (scratch714)Next time I have a bad coil, I'll change the remaining 4 all at once...easy to do.
Sounds good; but unnecessary. Coil Packs don't fail in a predictable pattern. They don't actually wear out; but some develop cracks or carbon tracks which will cause them to short out and cause mis-firings.

I had one fail at 95,000; a 2nd at 129,000; and a 3rd went out at 198,000. I'm now at 201,000, so two are original equipment and still doing the same job as when they were new.

FYI Tasca sells Volvo Coil Packs for $52.29.