Loud Valve - When Should I be Concerned?

If it is the valve, I would check the settings for all the valves.  You could also do a compression test to see if all the cylinders are consistant. The number 3 cylinder valve usually is the weak one due to it not getting sufficient air.  Worst thing if it breaks, it will damage cylinder, piston etc. Been there, done that, won't do it again. $$

Gary

With the "sudden" onset of this problem, I would look at the valve lash settings RIGHT NOW....  It could be a loose adjuster screw, bent pushrod, shaft keepers coming off, (stock spring rocker retainers) or something really expensive the longer you drive it.....  Just my .02....  

It also could be that one of those little wire / spring clips that keeps the rocker in the correct position ( centered right on top of the valve stem) may have broken and let the rocker get out of position. I'd look into things right away. Hopefully it's just a valve adjustment.

This one of those moments on "Car Talk" when Tom and Ray (especially Ray) would tell you to NOT drive the car, have it trucked to a mechanic and have them look at it right away.  If you drive it you could seriously screw things up for BIG $$$$$$$$'s!

ANY abnormal, loud valve noise, especially for a non-mechanical person, should be considered BAD and looked into before the car is driven any farther.

Cole - what all these ^ guys just said! Better safe than sorry!

As Gary pointed out - if a valve breaks off it beats holes in the piston and destroys the head.  It goes beyond that though.  It can bend the crank plus it sends little pits of metal thru out the engine which eats up bearings.  Result is need for a total disassembly and rebuild. 

 If you have a 13mm wrench and a slot screw driver  Just check it yourself  On the spot  if you have a serious problem then call the tow truck.   Sometime it just needs a tweek and your  back on your way.