I purchased my 2005 Silverado Z71 used with 77k miles on it about a month ago with no extended warranty from a local dealership. Within two weeks of purchase I had to have a new computer sensor put in the transfer case due to my 4wd service light coming on. I took it to the dealership which charged me $300 for it, ok, not excited about having to put that much money into it without even making a first payment on the vehicle but hey, I bought it used with no warranty so I got over it. Within the next 2 weeks the engine started running hot, so I checked the coolant level and it still had some in the reserve tank. I drove it to the same dealership about 10 minutes away and had the check it. Upon running diagnostics they called me back and said both cylinder heads were cracked and needed to be replaced for $2700. I figured I had no choice so I told them to go ahead, upon doing a little research on the internet I found out this is not so uncommon with "Castech" cylinder heads and GM has released bulletin #06-06-01-019B explaining the situation but never recalled the product. I spoke to the dealership and they confirmed I in fact had these specific cylinder heads. After reading what other customers have been through I determined it would be a waste of my time to contact GM for help in repair costs, I then contacted my personal mechanic with over 20 years GM certified mechanic and he agreed to fix it for half the cost. I realize this vehicle is not under warrranty and that I'm on my own on most repairs, however I expected GM to stand behind their products a little bit better than this. This will be the 6th GM vehicle and 5th Chevrolet I've owned, and I have to say I've spent more money on this truck in 1 month than all my other vehicles in 10 years combined. I think it is safe to say GM has one less customer now.