I have a 1997 Tahoe with 5.7L engine and only 87,000 miles on it. A couple of years ago my mechanic discovered a rust covered sludge when he took off the radiator cap. That cost me a new radiator and he warned that the intake manifold gasket would probably need replacing. Last week we took the Tahoe in for what appeared to be a heating problem and he discovered a bunch more sludge again. He went ahead and flushed the system, but said that the problem stems from the original coolant that Chevy put into the engine on 1996 - 99 vhehicles. The coolant turned out to be bad and is embedded in the walls of the engine. The engine walls will continue to corrode and there is nothing I can do about it. He suggested we trade the vehicle off while it still runs good. He also said that Chevy has taken no responsibility for this problem
Has anyone else heard about this "bad" coolant? What did you do about the problem?