2003 CLK320 compression issue HELP!!
 

HELP! My sister just called me. Her 03' CLK 320 is having issues. The mechanic just informed her that she needs a valve job. The car has about 135,000 miles. Is this too soon? Just had the cats replaced, plugs, and mass airflow sensor. WTH! Any suggestions? How much is a reasonable price for a valve job?

A valve job typically entails replacing the valve guides and seals as well as grinding the valve seats. At 135k, I highly doubt that any of those are in need of repair. In fact I've yet to see any of those engines actually NEED a valve job. The few that have had the heads off of were due to other failures, ingesting a foreign object for example. Before spending another cent on the car you need an explanation of WHY the car needs a valve job. It may be possible that the failed catalysts were neglected long enough to cause other problems but when the cats typically fail it's from a loose substrate, not plug-ups. Several questions need to be answered: Was a compression test done? Why were the catalysts replaced? Is this the same shop that did the previous work?