'99 With a Coolant Leak

No coolant in the oil, no oil in the coolant. It took a long time for the leak to be located. Only small amounts of missing coolant and the faint odor of a leak. Now it is a steady flow once hot. It appears to be a gasket behind the thermostat housing. Can't get a mirror in there to check/locate the exact location of the leak. Am assuming until I hear otherwise that this is the infamous Upper/lower intake manifold gasket leak. What is involved in tearing this thing down and doing the repair?

It might be, I just went out and had a uick look at my '97, there are small hoses going to the throttle plate, and a quick disconnect where the heater line comes into the manifold, any of which would cause a leak in that area, if you have the same motor (3.1)

Yep, it was the famous/infamous plastic lower intake manifold gasket. If one can be lucky, I was. The water/coolant leaked outside and not into the crankcase. It was a pain, but not really difficult enough to have to pay somebody to do it for me. Buy a Haynes manual and follow it step by step. One thing I would do different from their instructions. Leave the injector rail and injectors in place, it is a little more difficult, but not having to beat the injectors back into their holes - without messing them up - is a plus. Remove the fuel line and the pressure regulator from the injector rail and buy new o rings. Damn the piece of filth engineer(s) that designed the sideways 3.1 V6.

My 99 had a tiny, tiny leak (headgasket seal fails). Driving does the road on the, the rest of it went. Then stuff was crazy. Anti frees got in the oil. After that happened, the engine siezed (I broke 2 pitsons, plugs, and vallves.)