Leaky thermostat
It should be leakproof with the supplied gasket used alone. If it is leaking the flanges might have had residue on them, be distorted, or pitted. Although adding sealant "might" overcome those latter defects when you disassemble it just be...
02 Silverado extended cab 4.8. Wouldn't start. Put new full pump on, started up and drove it. Next day, wouldn't start. Exchanged fuel pump. Started right up. Drove it a while during the day. All of sudden, won't start. Mechan...
02 Silverado extended cab 4.8. Wouldn't start. Put new full pump on, started up and drove it. Next day, wouldn't start. Exchanged fuel pump. Started right up. Drove it a while during the day. All of sudden, won't start. Mechanic's Assistant: Have you ever replaced the fuel pump, or is this the original? Replaced 2 or 3 before on this truck. Mechanic's Assistant: Are you fixing your Cab yourself? What have you tried so far? Yes. Fuel pump, filter on rail.