Strange occurence 1994 100 CSQ (loss of coolant)

[David Torrey]

I had a similar experience last August during a trip to Boston with my '93
100 CSQ Wagon .  It was a hot day and the low coolant light came on along
with a corresponding rise in the engine temperature.  Made it to my
destination in Waltham,Ma. where I popped the hood and found the reservoir
full.  After allowing the engine to cool,  I removed the reservoir cap.  At
this point the coolant level dropped dramatically.  I refilled the reservoir
and discovered a leak under the car.  There was no coolant visible anywhere
in the engine compartment.  I drove home to Maine the next day with no
problems.  Here is my interpretation.  The thermostat housing on this engine
has an o-ring which seals the thermostat to the engine block.  I think the
leak was occurring here due to temperature increase and a fatigued seal.
Could possibly have been leaking around the water pump seal as well.  I am
not sure.

Two weeks later I replaced timing belt, tensioners, serpentine belt, water
pump and thermostat.  I found dry coolant residue in this area.  Couldn't
tell exactly where it was coming from.  I have had no problems since then.

I am somewhat puzzled why your leak occurred on a cool day.  Don't know if
this applies to your situation or not but thought I would contribute my
experience.

Best regards

David Torrey