Catalytic converter replacement - Cause
For the last month, every once in a while, my car will "hiccup" while I'm driving. There is clunk and a little jerk. During these hiccups, the check engine light will go on. Sometimes it turns off imediately, other times it will stay on for a few days and then go off.
So I took my car to the dealership today and this is what they told me: I need to replace 1 of my 2 cats @ a price of $1,515.
I was reading through other posts on the subject and found this:
"I need to caution you that cats will fail on 540i due to occasional misfire under heavy load. This generally occurs on M62 when the rearmost spark plugs and primary leads slowly become submerged in oil when the valve cover seals and gaskets seep or they leak & fail from a plugged engine ventilation system.
Replacing the cats without addressing root cause (oil leak) will result in another failure."
I have also been hearing a slight whirring sound coming from the engine, and I was told that it could be the PCV valve - positive crankcase ventilation.
Should I have the techs at Bob Smith investigate that? Could I have a ventilation problem as described above that made the cat go bad?
Any advice or information is welcome. Thanks!