I'm driving to work this morning and a grinding, clattering sound starts up breifly. The car stumbles a little, then it goes away. I know this isn't much of a description. Any suggestions on how to track down the source?

check your fan...sometimes they loosen and rub on the housing.

b

I agree with the fan. I got a paper cup stuck in mine running with no engine lid. Scared the $hit out of me

or when my valve dropped, it made a grinding or sliding noise...but after I stopped I wasnt going ANYWHERE.

b

I'm afraid it's something else besides the fan. I want to lunch and it's clatters a little at startup and is running a little rough. Beginning to think it's a valve train problem.

dropped valve seat. sounds like the engine tin is loose? BTDT just a month ago. Ran for around two months like that though....

b