93 100 CSQW: Overheating / Coolant Loss

[Eric Billing]

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Looking for help diagnosing the sudden problem on my wagon (132K miles).

The wife called me from the car and complained of a “hot smell” and that the
coolant/overheat warning was on. Had her pull over and pop the hood. Some
steam up by the firewall (fluid hitting exhaust I guessed). The coolant
reservoir was down 1 inch from MIN mark. Since she was only 3 miles from
home, I instructed her to continue home


I got home later that evening, by this time the car had cooled down
completely. The reservoir was empty (about 2 inches below MIN). I observed
drips back by the firewall mostly on the passenger side. However I couldn’t
find any apparent source.

Next day (after getting some coolant) I filled the reservoir (added about
1/3 gallon) and idled the car for about 10 minutes. As the temp came up, so
did the coolant level in the reservoir. A few iterations of burping out the
air resulted in some coolant expanding out the cap of the reservoir, which
was my only visible coolant loss. I let the car cool down, re-filled with
additional coolant (about ¼ gallon) to about mid-way between MIN/MAX, and
started her back up. Idled for another 30+ minutes. Temp gauge looks normal
(straight up). No leaks at all. Again the coolant expanded to beyond MAX,
but did not come out of the expansion tank. I let her idle for another 15
minutes or so. Temp gauge stays in the normal (I think) spot. Absolutely no
leaking back by the firewall.

At this point, the only observable coolant loss was due to my opening the
cap on the reservoir.

So this morning, with spare bottle of coolant in hand, I left for work. 32
degrees here in Mpls. My commute is mostly highway for about 40 minutes.
About 15 minutes into it, I notice that the temp gauge is pushing towards 1
o’clock. Another 15 minutes, and it’s a little higher, but appears to have
stabilized (definitely above normal, though). AT this point, I’m starting to
smell the “hot smell” of coolant on the exhaust manifold. As I pull into the
office parking lot, the coolant/overheat warning light comes on. I pull into
a parking spot, pop the hood (car still running) and observe slightly low
coolant level in the reservoir, and steam rising from the firewall area.
Down below reveals a series of dripping from both sides.

Questions:

a)       Obviously, my ride to work was a little more stressful than idling
in the driveway. However, both were for 30+ minutes. Would the absence of
symptom in the driveway scenario suggest anything useful?
b)       The coolant level was not terribly low this AM—yet the
overheat/coolant light came on. This, to me suggests overheat more than low
coolant. Make sense? If so what does this suggest?
c)       Any suggestions for additional things to check/test for?


Thanks in advance.

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Eric Billing
Eagan, MN 55123

1993 100csqw
1993 urS4

mailto:eric.billing at eds.com

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