You need to have this professionally diagnosed. As you can see, you're approaching this the most expensive and least effective way possible. That's by throwing random parts at a problem in hopes one will somehow fix it.
Balance shafts don't knock. In fact, other than the chain drive or timing belt, there's nothing on a balance shaft to fail. It's just a chunk of iron.
First you called it a knock, then a tick. To a mechanic those are very different things. You could have a slapping timing belt, a worn tensioner pulley, a lash adjuster that isn't pumping up, etc. Your mechanic will listen to how the sound changes with engine speed, load, and temperature. Piston slap will stop when the spark plug for the offending cylinder is grounded. There's a number of different things they will check.
Sunday, March 11th, 2012 AT 6:22 PM