For what it's worth. My son has an 02 Tahoe with 5.3. I talked with him today and he said his starter went out at 74,000 miles. Heater core went out at 81,000. Head gasket started leaking coolant into #4 cylinder at 85,000 miles. Two different dealerships told him that the Dexcool coolant will actually eat up heater cores and head gaskets if not changed and flushed every 25,000 miles.
Edited to add: My bad. He has a 2003, not a 2002
Edited to add: My bad. He has a 2003, not a 2002
