My 96 Chevy k1500 5.7 has 275k miles. Engine runs ok, but always rich, I don't think any O2 sensor works on the engine (per codes), and may have fouled cats as well. Mpg is never more than 10, and exhaust smells quite rich.
I smelled coolant today when driving it, and noticed coolant dripping at the rear/passenger side of the engine after it was parked a few minutes, dripping fairly rapidly. This dripped onto the exhaust pipe, which appears to be the source of the smell. I can't tell for sure, but it looks to be leaking on the passenger side, somewhere above the exhaust manifold area. There is a lot of oil buildup in this area, so hard to see for sure.
I'm assuming this is the lower intake manifold gasket? Are there other possibilities? I couldn't see leaks from the hoses, so have tentatively ruled them out.
Pinpoint the source of the leak with a dye kit.
I wouldn't fully rule out hoses on a truck that old. Especially if they're original. My 1999 Ranger developed a leak from a plastic T on a heater core hose. The source wasn't obvious until I squeezed the hose, there was a hairline crack that only opened up under pressure.
Do as @Doc says and run leak dye for cooling systems through it. A UV light will make the source obvious.
Thanks for the ideas. Should I run a pressure leakage test? I'm thinking that's a loaner tool at auto parts stores.
(edit) pressurize the cooling system..