recurring overheat problem

anyone experiencing a recurring overheat problem or have info on chronic failure in cooling system? I have been having the same overheat problem for 2 years and everytime I take it in I am told that it is a different component of the cooling system that has failed. This is the 4th time and now I am at a standoff with the dealership. Any advise?

First, I'll say that I have had numerous cooling system issues on my 2000 SLT+ with towing package, transmission cooler and HD cooling package, but I still love it, am driving it daily and have been treated more than fairly by the dealership and D/C regional management. It's the only issue that I have had over 66K miles. I bought it new and keep meticulous records of every service performed. A simple spreadsheet on my PC with who did the work, when, invoice number, mileage, what was done and the cost has been invaluable when dealing with D/C and the dealership, especially on recurring problems such as the one you are experiencing. Here is my story:
At 27K, the cooling fan stayed on after the engine was turned off. The dealer replaced the radiator/AC condensor fan motor relay under warranty.
At 35.8K, it overheated. They replaced (under warranty by 200 miles) the radiator, coolant reserve tank cap, fan and fan clutch and found that one of the cylinder heads had a hairline crack leading to the water jacket that they felt could be causing the problem over time. The cylinder head itself and head gasket were replaced, all under warranty.
At 44K, it began overheating again. This time, the thermostat was stuck open. Replaced thermostat and gasket along with coolant. 200 miles later, it overheated again. Replaced the radiator/condensor fan relay (again) - it was burned out.
At 51K, serious screeching from engine. Replaced water pump, belt and idler pulley.
At 59K, overheating again. Engine was torn down completely. Head gasket was ok on both sides. The cylinder head that was originally found to have the hairline crack was sent out for magnafluxing. I called and requested that they magnaflux the other one as well, and the dealer agreed. Both cylinder heads were found to be very slightly warped, and were redone. Replaced thermostat housing gasket and tensioner belt. Radiator was sent out and was found to be plugged and was unrepairable. Replaced radiator (again). Repairs were estimated at $2,500 from serious time spent on labor for the diagnostics and tear down - and I had heart failure. But I kept cool and calm in all dealings with the dealer and the regional D-C rep. Having the COMPLETE history and receipts saved me. My share of the cost ended up being $500. Bottom line, have the radiator yanked and flow evaluation done. Have the heads magnafluxed and check the wiring around the fan relay. D-C believes that faulty wiring started the entire scenario. I now have over 66K miles on it, and have had zero issues since. Good luck and I hope this helps you locate what your problem may be.