Have a 1997 TP with 3.4L, 165k miles, second engine. The add coolant light flashes and I can smell anti-freeze. Mechanic who replaced the engine claimed to put new upper/lower intake manifold gaskets in when he replaced the engine in April 2007. The excess coolant tank needs to be replenished about once a month - about a pint, but the stench of anti-freeze is quite prominent,
thanks. The temperature gauge is solid, does not fluctuate.

The smell of antifreeze is inside the van? If so this could be a heater core problem..

You don't by chance see any coolant on the ground at any time do you?

No I do not smell AF inside the van and have not noticed any on the ground.

Sounds like a small leak onto something hot & then burning off. Could be any one of the rubber hoses where they clamp on. Have a close look at whatever you can under the hood with the engine at operating temps.