28th Aug 2011, 14:07

Upper intake valve that connects to the engine. It cracks. It's hard to see the damage.

31st May 2012, 19:18

Just in case anyone is still reading these things: if the problem you're experiencing deals with the coolant emptying every few days, and you have to continually replace it, that's due to a cracked upper radiator housing. This piece is made of plastic, and either cracks or melts after roughly 90k miles. It's a known issue with this year and model; the part IIRC should cost like $90.