Which engine do you have: 2.7 or 3.2?
Any signs of water/coolant in the oil? Water pump of 2.7 can leak coolant directly into the engine (will ruin engine bearings).
3.2/3.5 can start leaking where the water pump ports connect to the crankcase(at rear of water pump). This does not go into the crankcase, but stays hidden behind the timing cover, leaving a pile of accumulated dry or muddy residue visible only with removal of timing covers.
If 2.7, the area of the coolant bleeder (top front center of engine). Starts seeping, leaving visible residue, and eventually rupturing, suddenly releasing coolant with possible severe overheating.
How does it run? Any missing? Any white smoke out the exhaust (cylinder head gaskets).
Old coolant reservoirs can develop micro racks and porosity in the plastic - coolant seeps out and evaporates, leaving no puddles of water. Look for powdery dry residue on outside surface of the reservoir. Eventually the plastic will suddenly split open for sudden loss of a lot of coolant and possible severe overheating. Also, the reservoir cap seal can harden and crack and seep liquid and vapor coolant into the overflow section out of the reservoir. Remove the cap and inspect the gasket for cracking or hardness.
Check plastic side tanks on the radiator. They are known to start splitting in a single vertical crack, first with seepage and no puddling, but eventually cracking open for sudden loss of coolant and possible severe overheating. Usually the crack is on the rear side of passenger-side tank close to where it joins the metal part of the radiator, but not always.
The radiator drain cock (bottom right rear side of radiator) can start leaking, but usually that only happens if disturbed (opened and closed). Coolant usually drips onto tray underneath radiator, may not puddle on ground if small drip rate.
Hoses seeping in holes in the rubber or at the clamped connections?
What is the position of the engine temperature gage after the engine warms up? Is it steady or does it fluctuate. (Low on coolant and/or thermostat needs replacing?)
'98 LXi - Later Concorde gages (black w/ chrome rings)/'99 LX - LHS gages (white) - HIR bulbs
Last edited by peva; 04-25-2019 at 06:56 AM.